Bats and fire: a global review

REVIEW Open Access

Bats and fire a global reviewSusan C Loeb1 and Rachel V Blakey2

Abstract

Background Bats are important components of forested ecosystems and are found in forests worldwideConsequently they often interact with fire Previous reviews of the effects of fire on bats have focused onprescribed fire effects in part due to the limited number of studies on bat responses to wildfire However over thepast several years studies on bat responses to wildfire and prescribed fire have increased considerably Wereviewed this rapidly expanding body of literature to determine whether bats respond differently to prescribed fireand wildfire and the important factors driving those differences We also examined regional similarities anddifferences in bat response to prescribed fire and wildfire and identified areas in need of further research

Results Our review included 52 studies (29 prescribed fire 23 wildfire) from North and South America EuropeAustralia and Africa although studies from Europe South America and Africa were limited In general we foundthat bats show positive or neutral responses to prescribed fire whereas a greater proportion of negative responseswere reported for wildfire However some of the negative responses to wildfire are short-lived or local suggestingthat bats may be resilient to the effects of fire Factors such as fire severity fire frequency time since last burn burnextent season of burn and pyrodiversity were all found to be important drivers of batsrsquo responses to bothprescribed fire and wildfire

Conclusions The importance of the spatial and temporal aspects of fire suggests that these factors need to beconsidered when designing future studies and interpreting results Pyrodiversity may be a particularly importantconcept to further our understanding of batsrsquo responses to fire We found several gaps in our knowledge includinglack of information on direct effects of fire (eg mortality) regional and taxonomic biases effects of wildfire onroosting habitat and the effects of climate change Although current studies suggest that fire may be an importantmanagement tool for improving bat habitat the threat of more frequent extensive and severe wildfires may putadditional stress on some bat populations particularly those being impacted by disease habitat loss andfragmentation and climate change

Keywords Bats Chiroptera Prescribed fire Pyrodiversity Wildfire

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Correspondence susanloebusdagov1US Forest Service Southern Research Station 233 Lehotsky Hall ClemsonUniversity Clemson SC 29634 USAFull list of author information is available at the end of the article

Fire EcologyLoeb and Blakey Fire Ecology (2021) 1729 httpsdoiorg101186s42408-021-00109-0

Resumen

Antecedentes Los murcieacutelagos son importantes componentes de los ecosistemas boscosos y se encuentran entodo el mundo En consecuencia a menudo interactuacutean con el fuego Revisiones previas de los efectos del fuegosobre los murcieacutelagos se han enfocado en los efectos de quemas prescriptas en parte debido al nuacutemero limitadode estudios sobre las respuestas de los murcieacutelagos a los incendios Sin embargo hace ya varios antildeos que estudiosde las respuestas de los murcieacutelagos a los incendios y a las quemas prescriptas se han incrementadoconsiderablemente Revisamos este cuerpo de literatura que se expande raacutepidamente para determinar si losmurcieacutelagos responden en forma diferente a las quemas prescriptas y a los incendios y la importancia de losfactores que producen esas diferencias Tambieacuten examinamos similitudes regionales y diferencias en la respuesta delos murcieacutelagos a las quemas prescriptas e incendios e identificamos aacutereas que necesitan maacutes investigaciones

Resultados Nuestra revisioacuten incluyoacute 52 estudios (29 quemas prescriptas 23 incendios) de Norte y SudameacutericaEuropa Australia y Aacutefrica aunque los estudios de Europa Sudameacuterica y Aacutefrica fueron limitados En generalencontramos que los murcieacutelagos muestran respuestas positivas o neutras a las quemas prescriptas mientras queuna mayor proporcioacuten de respuestas negativas fueron reportadas para incendios No obstante algunas de lasrespuestas negativas a los incendios son de corta duracioacuten o locales sugiriendo que los murcieacutelagos pueden serresilientes a los efectos del fuego Factores como la severidad del fuego la frecuencia del fuego tiempo desde lauacuteltima quema extensioacuten de la quema temporada de la quema y piro-diversidad se encontraron comoimportantes conductores de las respuestas de los murcieacutelagos tanto para quemas prescriptas como para incendios

Conclusiones La importancia de los aspectos espaciales y temporales del fuego sugieren que estos factoresnecesitan ser considerados en el disentildeo de futuros estudios y en la interpretacioacuten de los resultados La piro-diversidad puede ser un concepto particularmente importante para entender mejor las respuestas de losmurcieacutelagos al fuego Encontramos varios huecos en nuestro conocimiento incluyendo falta de informacioacuten de losefectos directos del fuego (por ej mortalidad) desviacuteos taxonoacutemicos y regionales efectos de los incendios en loshaacutebitats de descanso y los efectos del cambio climaacutetico A pesar de que los estudios actuales sugieren que elfuego puede ser una herramienta importante para mejorar el haacutebitat de los murcieacutelagos la amenaza de fuegosmaacutes frecuentes extensos y severos puede agregar un estreacutes adicional en algunas poblaciones de murcieacutelagosparticularmente aqueacutellas que estaacuten siendo impactadas por enfermedades peacuterdida de haacutebitat y fragmentacioacuten ycambio climaacutetico

IntroductionBats are a highly diverse group of mammals varyingbroadly in morphology life history ecology and conser-vation status (Willig et al 2003 Frick et al 2020) Theyare found on every continent except Antarctica and oc-cupy a diversity of habitats ranging from deserts to rain-forests and may be found from the equator to the Arcticas well as in remote urban and agricultural areas Des-pite the diversity of habitats which bats utilize most batspecies rely on forests to some extent as forests providecritical resources for foraging roosting and drinkingwater (Law et al 2016) Because forests throughout theworld often experience fire both natural and human-ignited bats often interact with fireFire may have direct and indirect effects on bats (Perry

2012) Direct effects include immediate mortality as wellas carbon monoxide toxicity and tissue damage such asear burns (Dickinson et al 2010) Fires may also resultin the need to abandon roosts (Moorman et al 1999Dickinson et al 2009 Jorge et al 2021) making batsmore vulnerable to predation Indirect effects resultfrom changes in the habitat and include the creation or

loss of suitable roost sites changes in foraging habitatstructure and changes in the insect prey base (Perry2012) Indirect effects may be positive neutral or nega-tive For example use or activity of some bat species in-creases after prescribed fire or wildfire while that ofother species declines or does not change (eg Inkster-Draper et al 2013 Austin et al 2018a 2018b Law et al2018b Ancillotto et al 2020)Due to the lack of research on bat responses to fire

prior to the early 2000s Carter et al (2002) reviewedsome of the potential effects of prescribed fire on bats inthe eastern USA and developed several hypotheses abouthow fire may affect their roosting and foraging behaviorPerry (2012) provided a more thorough review of the ef-fects of fire on bats in the eastern oak region of theUSA but most of the papers included in his review ex-amined the effects of prescribed fire on bats More re-cently Loeb (2020) synthesized the literature on effectsof silvicultural treatments including regeneration har-vests thinning gap formation plantation forestry andfire on bat activity and habitat use in temperate zoneforests Like Perryrsquos (2012) review most of the fire

Loeb and Blakey Fire Ecology (2021) 1729 Page 2 of 18

studies included in that review pertained to prescribedfire The reviews by both Perry and Loeb concluded thatalthough responses of bats to fire vary among speciesoftentimes in relation to their ecological and morpho-logical characteristics in general prescribed fire tends tohave either neutral or positive effects on bats Due to thelow number of wildfire studies included in the previousreviews it is not clear whether bats respond to wildfireas they do to prescribed fire Wildfires are often largerin extent than prescribed fires (eg 100000s ha versus100s ha) and more severe causing extensive damage toforests and human communities (Hunter and Robles2020) Thus their effects on bats may differ from those ofprescribed fire Further neither review examined the ef-fects of fire parameters such as burn severity time sincelast burn burn extent fire frequency or pyrodiversity onbatsWildfires have been increasing in frequency severity

and extent throughout fire-prone regions of the world inrecent decades and there is broad scientific consensusthat this is due to a warming and drying climate as wellas other anthropogenic disturbances including fire sup-pression increased human caused ignitions removal ofgrazers and the cessation of indigenous fire manage-ment (Jolly et al 2015 Bowman et al 2020) The use ofprescribed fire has also been increasing in part to reducefuel loads to mitigate the effects of wildfires as well as torestore ecosystems However increasing periods ofdrought and monsoon may reduce the number of dayssuitable for prescribed fire thereby leading to more in-tense wildfires (Chiodi et al 2018) Megafires such asthose that occurred in Australia in 2019ndash2020 and else-where in recent years can have devastating effects onwildlife (Ward et al 2020) For example Bosso et al(2018) estimated that suitable habitat for the 12 bat spe-cies in Vesuvius National Park in southern Italy declinedby approximately 40 for species that foraged in openareas but up to 60ndash80 for species that were dependenton interior forests after a severe wildfire burned roughly40 (~ 3400 ha) of the park Not only did the fire des-troy habitat but due to forest loss it also increased frag-mentation for species associated with closed forestsMany bat species across the globe are endangered or

threatened due to habitat loss and fragmentation dis-ease wind energy development urbanization and cli-mate change (Frick et al 2020) Currently 23 of theworldrsquos bat species are considered to be globally threat-ened (listed as critically endangered endangered vulner-able or near-threatened on the IUCN Red List) with78 of species with either unknown or decreasing popu-lation trends (IUCN 2020) Thus understanding the ef-fects of fire on bats is critical for developing effectivemanagement guidelines and policies to prevent furtherendangerment and foster recovery Over the past few

years several papers have been published on the re-sponse of bats to wildfires Thus we are better able tocompare and contrast batsrsquo responses to prescribed fireand wildfire Our objective was to review the literatureon the responses of bats to prescribed fire and wildfireto address the following questions (1) How do bats re-spond to the occurrence of prescribed fire and wildfire(2) How do bats respond to various fire parameters in-cluding (a) burn extent (area burned) (b) fire frequencyfire return interval and time since last burn defined asthe number of fires in an area over a given time intervalthe average number of years between fires and monthsor years since the most recent fire respectively (Som-mers et al 2011) (c) burn season (often described asgrowing season versus dormant season or wet versus dryseason) (d) burn severity (a firersquos effect on the ecosys-tem particularly the aboveground and belowground or-ganic material) or intensity (energy released during afire Keeley 2009) and (e) pyrodiversity (spatial and tem-poral variability in post-fire landscape characteristicsJones and Tingley In Press) (3) Do bats respond differ-ently to prescribed fire and wildfire (4) What drives re-gional differences and similarities in bat response toprescribed fire and wildfire globally (5) What arecurrent information gaps and how can we best designresearch to address these gaps

Review approach and available literatureWe used the ISI Web of Science and included the Webof Science Core Collection BIOSIS Citation Index BIO-SIS Previews Current Contents Connect and ZoologicalRecord to search for papers on responses of bats to pre-scribed fire and wildfire through April 2021 Topicsearches were [ldquobat OR chiroprdquo AND ldquofirerdquo] [ldquobat ORchiroprdquo AND ldquoburnrdquo] [ldquobat OR chiroprdquo AND ldquowild-firerdquo] and [ldquobat OR chiroprdquo AND ldquoprescribedrdquo] We alsoexamined the literature cited sections of these papers foradditional references For each paper included in the re-view we determined the type of fire examined (pre-scribed fire or wildfire) the fire parameter(s) examined(eg burn versus no burn time since last burn severity)the response examined (foragingcommuting roostingphysiology demographic or range distributions) andthe response (positive negative or neutral) of each spe-cies or species group (either foraging guild or genus)Examples of positive responses included increased for-aging or commuting activity or occupancy in burnedcompared to unburned sites greater activity or occu-pancy in recently burned sites compared to sites burnedat a greater time interval and selection of roosting sitesin or near burned areas compared to non-burned areasNegative responses included lower activity or occupancyin burned areas compared to non-burned areas loweractivity or occupancy in more severely burned sites and

avoidance of burned sites for roosting Although higherbat activity is often interpreted as a positive response toa treatment such as a fire it is possible that high activitycould be reflecting animalsrsquo need to forage more in theseareas to obtain the resources they need and lower for-aging rates could reflect high efficiency Further werecognize that other factors may also be contributing toresponses of bats to fire such as logging history otherland uses and invasive plants and have noted thesewhere appropriate We also determined the foragingguild (closed-space edge-space or open-space) of eachspecies based on the literature We defined closed-spaceforagers as species that forage primarily in interior for-ests open-space foragers as those species that forage pri-marily in open habitats such as fields forest gaps orforests with relatively open canopies and little mid-storyand edge-space foragers as those species that can useboth open and closed forests and often use the edges be-tween (Aldridge and Rautenbach 1987 Fenton 1990)Open-space foragers are usually characterized by longnarrow wings and large body sizes whereas closed-spaceforagers are usually small-bodied with short broadwings which makes them more agile in closed spacesEdge-space foragers tend to have intermediate character-istics We limited our review to echolocating bats be-cause of the strong relationships between echolocatingbats and vegetation structureWe found 49 published papers and three theses that

addressed the effects of fire on bats 29 studies on pre-scribed fire and 23 studies on wildfire We were not ableto find any studies that addressed the effects of fire onbats prior to 2005 but the number of studies on bothprescribed fire and wildfire has increased since thenparticularly the number of wildfire studies in 2019 2020and early 2021 (Fig 1A) Eleven studies were fromAustralia one study was from Africa two studies werefrom Europe two studies were from Brazil and 36 werefrom North America (one from Canada the rest fromthe USA) No studies from western North America ex-amined prescribed fire whereas only one study fromeastern North America examined wildfire (Fig 1B and2A) Four of the 29 prescribed fire studies and two ofthe 23 wildfire studies were Before-After-Control-Impactdesigns while the remainder of the studies were eitherspace-for-time (eg retrospective post-treatment versuscontrol experiments) or foraging or roost habitat selec-tion studies conducted with radiotelemetry Thirty-eightof the studies (23 prescribed fire 15 wildfire) examinedforaging responses of bats and the majority of these (30)used acoustic detectors while five studies used radiote-lemetry and three used mist-net captures Eleven studiesexamined roost responses (including two that examinedboth foraging and roosting responses) only three ofwhich examined roosting responses to wildfire One

study examined physiological responses of bats to wild-fire one study examined demographic responses to wild-fire in addition to examining foraging responses andtwo studies used species distribution models of databaseoccurrences or range maps along with remotely sensedburn layers to make inferences about associations be-tween bat distributions and pyrodiversity across Africaand southeastern Australia

Bat responses to burned versus unburned sitesMost bat species respond in either a positive or neutralway to prescribed fire (Additional file 1) However someedge- and edgeopen-space foraging bats in two studiesin northern Australia (Inkster-Draper et al 2013Broken-Brow et al 2020) show negative responses toprescribed fire although in one study this only occurredafter high-intensity fires (Additional file 1) Reduction invegetation clutter or the creation of small gaps due toprescribed fire most likely contributes to the increase inbat use in response to prescribed fire compared to con-trol sites (eg Smith and Gehrt 2010 Cox et al 2016Griffitts 2016 Silvis et al 2016 Burns et al 2019 Blancoand Garrie 2020 Smith et al 2020) Foraging efficiencyis higher in more open habitats particularly for edge-and open-space foragers (Aldridge and Rautenbach1987 Fenton 1990) However in some studies the pre-scribed fires may not have been intense enough to re-duce clutter resulting in neither positive nor negativeresponses (Austin et al 2018a) An increase in the insectprey base after prescribed fire may also contribute topositive responses to prescribed fire in some areas (Lackiet al 2009) but not in others (Cox et al 2016) The rela-tionship between insects and fire is complex and de-pends on the local insect community as well as manyother factors including time of year that sampling oc-curs time since the burn and burn severity (Perry2012)Positive responses to prescribed fire are particularly

evident in terms of roost responses In six of the eightstudies that examined roost responses of bats to pre-scribed fire bats were more likely to select roosts in ornear prescribed burn sites than unburned sites and inthe other two studies there was a neutral response (egJohnson et al 2009 2010 Thalken and Lacki 2018 seeAdditional file 1) For example Myotis sodalis (Millerand Allen) in northern Arkansas select mature foreststands that had been burned at least once for roostingand avoid unburned forests (Perry et al 2016) Largecanopy gaps or low clutter resulting from prescribed firemay increase solar radiation on roost trees resulting inlower energetic costs for thermoregulation (Boyles andAubrey 2006)Compared to prescribed fires a greater number of bat

species show negative responses to wildfire (Additional

file 2) Some of the species that show negative responsesare closed-space foragers (eg Nyctophilus spp Rhinolo-phus ferrumequinum [Schreber] Plecotus austriacus [JB Fischer]) but some are edge-space (Vespadelus dar-lingtonia [G M Allen] V vulturnus [O Thomas] Hyp-sugo savii [Bonaparte]) or open-space foragers(Saccolaimus flaviventris [Peters]) However eventhough the number of bat passes by R ferrumequinumand P austriacus significantly declined 1 year after awildfire in Southern Italy they either recovered to pre-burn conditions or showed positive responses 2 yearsafter the fire compared to pre-fire activity (Ancillottoet al 2020) Similarly the proportion of reproductive

female H savii in this same study declined in the yearfollowing the fire but returned to pre-fire levels 2 yearsafter the fire This suggests that time since last burn isan important variable to consider in studies of responsesof bats to fire as discussed belowTwo studies compared roosting behavior of bats in

areas that experienced wildfire to non-burned areas My-otis evotis (H Allen) a closed-space forager roosts far-ther from burned areas than randomly located roosts insouthwestern Colorado (Snider et al 2013) Insect abun-dance was also higher in unburned areas suggesting thatbats may have selected roosts in unburned areas to de-crease foraging costs (Snider et al 2013) In contrast M

Fig 1 Temporal (A) and spatial (B continental scale) distribution of studies that examined prescribed fire and wildfire on bats from the firstidentified study in 2005 through April 2021 The data for 2020 includes five papers that were published in 2021 or are in press

evotis and M lucifugus (Le Conte) in Montana roost al-most exclusively (91 of roost days) within mixed sever-ity burn sites in Montana 1ndash2 years post-fire (Schwab2006) In further contrast with the Snider et al (2013)study insect abundance was almost twice as high inburned areas compared to unburned areas The differ-ences between the two studies may have been due to theenvironmental conditions and insect communities expe-rienced by bats in the two study areas The southwesternColorado study area was in the semi-arid Upper SonoranDesert and the authors speculated that bats selected un-burned areas because they represented less harsh condi-tions (higher humidity less variable and extremetemperatures) compared to burned areas In contrast

the Montana study was conducted within two riverdrainages and thus the environmental conditions mayhave been less harsh and more favorable for bat roostingand foraging Further the responses of the insect com-munities to the wildfires may have varied between thetwo sites due to fire severity seasonal timing previousmanagement and the insect community (Swengel 2001)

Effects of fire parameters on batsmdashburn extentAustin et al (2018b 2020) found no significant effects ofthe extent of either prescribed fires or wildfires on bathabitat use in the central Appalachian Mountains of Vir-ginia (Additional files 3 and 4) Prescribed fires rangedfrom 1 to 8 years old but the areas covered by the

Fig 2 A Global distribution of studies that examined relationships between bats and fire and B inset of North American studies showingdistribution of wildfire (triangle) and prescribed fire (star) studies The underlying map shows fire potential measured by the linear trend in thenumber of days annually that exceeded the 95th percentile of the Fire Weather Index over the years 1979ndash2019 These data were reproducedwith permission from Bowman et al (2020) Both panels are shown in the WGS84 coordinate reference system

prescribed burns were not reported In contrast thewildfires ranged from 3 to 85 years old and wildfire burnextents ranged from 20 to 9322 ha The authors sug-gested that the time since fire for many sites was so longthat the structural changes to the forest were no longerbiologically relevant (Austin et al 2020) In contrastLaw et al (2020) found a positive relationship betweenburn extent and activity of several edge- and open-spaceforagers for wildfire burns lt 5 years old as well as burnsthat were 5ndash15 years old Only one species Chalinolobuspicatus (Gould) an edge-space forager showed a nega-tive response to the extent of recent burns (lt 5 years)however this species did not have a negative response tothe extent of older burns Further the presence of Cpicatus at the landscape scale was relatively stable overthe 5 years (Law et al 2020) and its distribution acrossthe Murray Mallee Region of southeastern Australia isnot affected by burn extent (Senior et al 2021) suggest-ing that the negative effects of recent wildfire extent arelocal for this species However the distributions of sev-eral other species of bats in the Murray Mallee Regionare negatively associated with burn extent (Additionalfile 4) Blakey et al (2021) related bat species richnessin mixed-conifer forests of the Sierra Nevada Califor-nia to extent of areas burned by wildfires in the 30years prior to the study measured as proportion ofcircular buffers with 1ndash10-km radii and found thatbat species richness was positively associated withburned area extent across all buffer sizes They con-cluded that bat communities of the region were resili-ent to wildfire and potentially adapted to the

heterogeneous forest structures that likely occurredprior to the era of fire suppression

Effects of fire parameters on batsmdashfire frequencytime since last burn and fire return intervalTemporal aspects of fire such as fire frequency timesince last burn and fire return interval are importantdrivers of bat responses to both prescribed fire and wild-fire (Fig 3) Three studies examined the effects of pre-scribed fire frequency and two studies examined theeffects of wildfire frequency on bat habitat use (Add-itional files 3 and 4) In southeastern Australia the effectof prescribed fire frequency varies with logging history(Law et al 2019) Bat activity in sites that have been pre-viously logged and thus represent thick regrowth ishigher where prescribed fires are more frequent (burnedevery 2 years compared to every 4 years) In contrast inunlogged sites activity is higher in those sites burnedevery 4 years compared to every 2 years Higher fre-quency burns in the logged sites are more effective at re-ducing stem density than routine burning (every 4years) Nonetheless the effect of fire frequency is smalland logging history and its effect on forest structurehave a greater effect on bat activity and species richnessthan fire frequency (Law et al 2019)In Florida the effects of prescribed fire frequency on

Eumops floridanus (G M Allen) vary with season ofburn and consequently fire intensity (Braun de Torrezet al 2018b) Overall activity and foraging activity arehigher in sites burned every 3ndash5 years (moderate fre-quencies) compared to sites burned at low frequencies(gt 5 years) during the early wet season (AprilndashJune) but

Fig 3 Examples of studies from various regions and fire types (wildfire and prescribed fire) that have directly examined the spatial (top) andtemporal (bottom) components of the relationship between bats and fire

for sites burned during the cool dry season (JanuaryndashMarch) activity is higher in sites burned at low frequen-cies than at moderate frequencies As discussed belowthe most effective burn schedules for managing bat for-aging habitat in an area may be those that best mimicthe historical fire regime which in south Florida is theearly wet season based on burn seasons prior to Euro-pean colonization (Braun de Torrez et al 2018b) Star-buck et al (2015) also found a positive relationshipbetween evening bat (Nycticeius humeralis) (Rafinesque)habitat use and frequency of prescribed fires but foundneutral effects for all other species analyzed (Additionalfile 3) Evening bats are often associated with savannas(grass forb and shrub dominated ecosystems withwidely spaced trees) and woodlands (open forests with gt50 canopy but little mid-story and a ground layer dom-inated by forbs and woody species Dey and Kabrick2015) both of which can be maintained with frequentlow-intensity fires (Greenberg and Collins In Press)Responses to wildfire frequency appear to vary with

species Milne et al (2005) found that a community ofbats made up primarily of edge-space foragers in north-ern Australia was positively associated with wildfire fre-quency whereas other bat communities were neitherpositively or negatively associated with fire frequency Incontrast P austriacus a clutter-tolerant bat avoidsareas that have burned more than three times in the past30 years though these areas make up most of the land-scape in northeast Iberia (Loacutepez-Baucells et al 2021)Bats in the eastern USA respond in either a neutral

way to time since last prescribed fire (Austin et al2018b) or are positively associated with more recentburns (Armitage and Ober 2012 Burns et al 2019) Forexample activity of open-space foragers and two edge-space foragers (Lasiurus borealis [Muller] and L semino-lus [Rhoads]) is higher in recently burned sites com-pared to sites burned gt 8 years before sampling inFlorida (Armitage and Ober 2012) Perimyotis subflavus(F Cuvier) an edge-space forager is also more likely tooccupy more recently burned stands in the CumberlandPlateau (Burns et al 2019) Because vegetation often re-grows after burns and becomes dense after several yearsbats may prefer more recently burned stands due tolower clutter in those standsTime since wildfire also appears to be an important

factor in assessing wildfire effects on bats For exampleactivity of two closed-space foragers in southern Italydecreased in burned areas the year after a wildfire butrecovered to pre-burn levels 2 years after the fire (Ancil-lotto et al 2020) Demographic responses of H saviifollowed the same pattern Similarly activity of manyspecies of Australian bats returns to pre-burn levels 4years after a wildfire after showing significant decreases1-year post-fire (Law et al 2018b) In the Pantanal forest

of Brazil burned forests are used by sanguivorous car-nivorous frugivorous and gleaning insectivorous bats 3months after a wildfire but primarily by frugivorous batsonly 3 months later (6 months post-fire) (Santos et al2021) The authors suggested that reduction in vegeta-tion clutter immediately after fire facilitates hunting andgleaning activities by predators for a short period afterwhich regeneration of fruiting plants provides resourcesfor frugivorous batsWhile the above studies examined batsrsquo responses in a

relatively short period of time after wildfires (3 monthsto 4 years) Blakey et al (2019) examined batsrsquo responsesto burns where time since last burn was 3ndash107 yearsThey found that in the montane forests of California oc-cupancy of M lucifugus declined as time since last fireincreased while occupancy of Eptesicus fuscus (Palisotde Beauvois) increased up to about 30 years post-fireleveled off at its highest point from about 30ndash60 yearspost-wildfire and then decreased at about 70 years post-fire Fire return interval had no effect on occupancy inthe same study However other factors such as insectoutbreaks succession and land use change could alsohave influenced occupancy across the landscapeNyctophilus geoffroyi (Leach) a closed-space forager in

Australia exhibits contrasting responses to time sincelast burn at the local (Doty et al 2016) and range-widescale within southeastern Australia (Senior et al 2021)Torpor use is significantly lower 4 months after a wild-fire compared to 2 years post-fire which the authors at-tribute to an increase in vegetation on the forest floorover time Nyctophilus geoffroyi hawks insects in mid-airbut also captures prey from the forest floor Thus a re-duction in ground vegetation may facilitate prey captureon the forest floor thus reducing the need to use torporto compensate for energy deficits In the drier and moresparsely vegetated Mallee region occurrence of N geof-froyi is associated with areas that had not burned for upto 100 years at the landscape scale (100000 km2) likelydue to slow regeneration times of suitable roostsSeveral studies have also examined the short-term

(hours to days) effects of fire on bat habitat use Activityof E floridanus increases significantly during the 24 daysafter prescribed fires in Florida compared to the 12 daysbefore the fires and peaks 9 days after the fire (Braun deTorrez et al 2018a) While structural changes to thehabitat may have been responsible for this immediate ef-fect the authors speculated that bats were most likelyattracted to burned areas because of an increase in preyavailability or accessibility In contrast bat species rich-ness and diversity increase gradually one night to 7months after a wildfire in a gallery forest of the BrazilianCerrado most likely in response to recovery of the forestcanopy and a gradual increase in available resources (deOliveira and Aguiar 2015) In tropical northern

Australian forests bat activity doubled at burned sites2ndash39 days after prescribed fire coupled with a commu-nity shift towards edge- and open-adapted species (Ink-ster-Draper et al 2013) Immediate responses ofroosting bats are of particular interest because bats aremost vulnerable while they are in their roosts In Ken-tucky two M septentrionalis (Trouessart) left theirroosts within 10min of a spring prescribed fire being ig-nited during the late afternoon approximately 20 m fromtheir roosts (Dickinson et al 2009) Similarly one Lseminolus and one L borealis flushed approximately 10min after a prescribed burn was ignited near their roost(also during the late afternoon) in Florida (Jorge et al2021) Both the L seminolus and L borealis flew to roosttrees in nearby mesic forests In contrast five other batsin the Florida study did not evacuate their roosts butpresumably survived after ignition of a prescribed firenear their roosts but these bats roosted in taller treesand the fires that were set near their roosts were muchlower intensity with lower mean flame heightsOnly one study examined the effects of prescribed fire

return interval During winter L seminolus in northernFlorida select day roosts in areas with longer mean firereturn intervals particularly in mesic sites (Jorge et al2021) Since prescribed fires are usually conducted inwinter in this area the use of areas with longer fire re-turn intervals may reduce the need to evacuate roostsduring burning

Effects of fire parameters on batsmdashburn seasonPrescribed fires in the southeastern USA are usuallyconducted during the non-growing season althoughgrowing season burns are becoming more common inthe Coastal Plain (Knapp et al 2009) and other regionssuch as the eastern broadleaf and Appalachian forests(Arthur et al In Press) In the western USA prescribedfires are often conducted during spring or early summerSpring and fall are also typical times for prescribed firesin southern Australia (McCaw 2013) while prescribedburns are mostly conducted in the early or late dry sea-son in northern Australia (Broken-Brow et al 2020)Prescribed fire seasons often do not coincide with thehistorical fire season due to operational considerationsas well as concerns about the direct and indirect effectson wildlife (Knapp et al 2009) However E floridanusrespond most favorably to prescribed fires conductedduring the historical season which is April to June (earlywet season) (Braun de Torrez et al 2018b) In the Cum-berland Plateau of Tennessee foraging activity of severalspecies is greater in sites that are burned in the springcompared to the fall but amount of thinning is also afactor (Cox et al 2016) Seasonal differences in bat re-sponses to fire are likely due to timing of fire in relationto bat and prey life cycles as well as intensity of fires in

various seasons For example in northern Australiaearly dry season fires are usually low severity whereaslate dry season fires are usually high severity (Russell-Smith and Edwards 2006 Broken-Brow et al 2020)

Effects of fire parameters on batsmdashburn severityor intensityTwo studies examined the effects of prescribed fire se-verity on bats of the Cumberland Plateau of Kentuckyand Tennessee with contrasting results Lacki et al(2017) found no effect of burn severity on bat activity inMammoth Cave National Park whereas occupancy ofmedium-severity burn sites by P subflavus and Myotisspp is significantly lower than occupancy of low-severityburn sites in Big South Fork National River and Recre-ation Area (Burns et al 2019) Burns et al (2019) sug-gested that medium-severity fires may reduce clutterbelow a threshold that is preferred by some closed-spaceforagers Differences between the studies may be due todifferences in measures of use (activity versus occu-pancy) or because Lacki et al (2017) grouped all batswith echolocation frequencies gt 34 kHz thus obscuringspecies-specific responses For example Myotis spp andP subflavus whose echolocation calls are ~ 40 kHzwould have been included in the gt 34 kHz group Be-cause populations of Myotis spp and P subflavus havedeclined considerably in this area due to white-nose syn-drome (Thalken et al 2018) the gt 34 kHz group wasprobably made up primarily of L borealis and N humer-alis both edge-space foragers who may be less likely tobe negatively impacted by higher severity firesIn tropical northern Australia two prescribed burn in-

tensities are commonly used by land managers low-intensity burns which are generally applied in the earlydry season and high-intensity burns which are generallyapplied in the early wet season for weed control(Broken-Brow et al 2020) In a BACI experimentBroken-Brow et al (2020) found that 2ndash4 weeks post-fireedgeopen-space foragers respond negatively to high-intensity prescribed fires but respond positively to low-intensity fires (Additional file 3) In contrast open-spaceforagers respond positively to high-intensity fires but haveneutral responses to low-intensity firesThe effects of wildfire burn severity on bats in the

western USA vary considerably across studies Based ona trait analysis Blakey et al (2019) concluded that batswith traits consistent with clutter tolerance in mixed-conifer forests of California are associated with less fre-quent fires and less severe burns whereas bats withtraits adapted to open areas are positively associatedwith frequent high-severity burns However in anotherstudy of the effects of wildfire severity on bats in mixed-conifer forests of California two closed-space foragingspecies or groups (M thysanodes [G S Miller] and

Myotis with echolocation calls in the 40 kHz range) werepositively associated with higher severity burns(Buchalski et al 2013) Similarly Steel et al (2019) foundpositive associations between six bat species (closed-space open-space and edge-space foragers) and burnseverity in mixed-conifer forests across four national for-ests in California In southeastern Arizona open-spaceforagers show a moderate positive response to burn se-verity whereas closed-space foraging bats with high-frequency calls show a negative response to burn sever-ity (Saunders 2015 Starbuck et al 2020) However Star-buck et al (2020) found that landscape variables such aselevation and water density are better predictors of bathabitat use than burn severity Saunders (2015) also ex-amined roost selection in this landscape and found noeffect of burn severity on selection of roosts Variationsin bat responses among these studies may be related todifferences in times since fires or differences in land-scape composition and environmental conditions Forexample in the arid southwest USA water availability isparticularly important and may override burn factors(Starbuck et al 2020)

Effects of fire parameters on batsmdashpyrodiversityIn the same way that heterogeneous habitats provide abreadth of niches for species with different habitatneeds pyrodiversity is hypothesized to lead to higherbiodiversity by providing a range of habitat structuresand resources resulting from spatio-temporal variationin fire characteristics (Jones and Tingley In Press) Be-cause bat responses to burned landscapes are variableamong species based on ecological and morphologicaldifferences it follows that bat diversity is likely to bepositively associated with pyrodiversity in fire-prone re-gions (Blakey et al 2019 Burns et al 2019 Broken-Browet al 2020) This is supported by studies in Africa wherebat species richness is positively associated with pyrodi-versity in wet regions (Beale et al 2018) and in thewestern USA where two studies in the Sierra Nevadafound positive relationships between bat richness andpyrodiversity across scales from 250m to 10 km (Steelet al 2019 Blakey et al 2021) However when consid-ered at the species level bats have variable responses topyrodiversity with only three species showing a positiveassociation with pyrodiversity in a western USA assem-blage of 17 species (Steel et al 2019) and 8 out of 9 spe-cies in semi-arid Australian woodlands being negativelyassociated with pyrodiversity (Senior et al 2021) Theoverwhelmingly negative relationship between bat spe-cies and pyrodiversity in the Australian landscape (mea-sured by diversity in post-fire age classes) is likelybecause bat roosting habitat is limited in this environ-ment and takes gt 40 years to regenerate after severewildfires (Senior et al 2021) In other landscapes such as

the Sierra Nevada of California pyrodiversity results in aheterogenous landscape consisting of stands of differingstructure and suitable roosting and foraging habitat isprovided for a wide range of species with varying life his-tories and morphologies (Steel et al 2019 Blakey et al2021)

Bat responses to firemdashprescribed fire versuswildfireMost studies included in this review indicated that pre-scribed fire had neutral or positive effects on batswhereas a greater proportion of negative responses werereported for wildfire However where bat responses towildfire were studied over time they appeared to belargely resilient to the effects of wildfire often recoveringfrom any negative effects within a few years Furtherthis review suggests that the characteristics of fires andtheir interactions with environmental factors may bemore important in driving bat responses than the dis-tinction between prescribed fire and wildfireThe scales of the fires and the designs employed in

studies that examined them relative to the home rangeof the bats also need to be considered when comparingprescribed fire and wildfire (Fig 3) For example manyof the studies that have tested the effects of prescribedfire have been conducted at the stand scale (10ndash20 haLoeb and Waldrop 2008 Cox et al 2016 Smith et al2020) whereas those examining wildfire are often con-ducted at the landscape scale (8000ndashgt 463000 ha Jemi-son et al 2012 Steel et al 2019 Ancillotto et al 2020Austin et al 2020 Law et al 2020 Blakey et al 2021)Although some bats have relatively restricted foragingranges (~ 05 km from the roost Waldien and Hayes2001) others such as Brazilian free-tailed bats (Tadaridabrasiliensis [I Geoffrey Saint-Hilaire]) or spotted bats(Euderma maculatum [J A Allen]) can fly 30ndash56 kmper night (Best and Geluso 2003 Chambers et al 2011)The vagility of bats suggests that we should not makedirect inferences or comparisons between the results ofstand and landscape-scale studies For example while Cpicatus activity is negatively related to the extent of re-cent burns at the stand scale its presence across thelandscape is relatively stable over time suggesting thatthe effects of fire are localized (Law et al 2020) None-theless at the community scale relationships betweenbat richness and wildfire extent configuration and pyro-diversity are relatively consistent across scales from ~ 3ndash30000 ha (Blakey et al 2021)It is evident from our review that bat responses to

both prescribed fire and wildfire are complex and varywith a number of factors including burn extent timing(season and time since fire) severity and pyrodiversityand environmental factors such as forest type structureand health as well as topography ecoregion and climate

as well as the ecology of the bats themselves Furthermany of the fire parameters are not independent For ex-ample in a managed forest of the Sierra Nevada Califor-nia burned area extent is highly correlated (|R| gt 07)with mean burned patch area edge density and pyrodi-versity across scales from ~ 300 to 30000 ha (Blakeyet al 2021)Understanding the spatial temporal and taxonomic

dimensions of relationships between bats and fire islikely to help unravel the differences between prescribedand wildfire as well as regional differences across envi-ronments fire regimes and bat communities Studiesthat deal directly with spatial and or temporal aspects ofthe bat-fire relationship are valuable for making theselinks (Fig 3) For example at smaller spatial scales (~ 1ha) bats are likely to respond to fine-scale features suchas basal area (Blanco and Garrie 2020) but at largerspatial scales (80000 ha) bats are more likely to respondto factors such as configuration of burned areas (Blakeyet al 2021) Furthermore the scale at which bats re-spond most strongly to fire varies among species likelydue to varying levels of mobility For example closed-space bats with high-frequency calls are negatively asso-ciated with burn severity at fine (90-m radius) spatialscales while edge- and open-space bats with low-frequency calls are positively associated with burn sever-ity at coarser spatial scales (576-km radius) (Starbucket al 2020) (Fig 3)

Knowledge gapsBat mortality from fire eventsAlthough it has been suggested that bats may suffer dir-ect mortality during fires resulting from being burnedsmoke inhalation heat exposure (Dickinson et al 2010OShea et al 2016) or as a result of predation whenevacuating roosts (Hovick et al 2017) few data are avail-able on the magnitude of this mortality Based on la-boratory experiments of Australian and US bat speciesbats may take gt 20min to respond to smoke and soundcues of fire when in torpor with longer times to arousalat lower ambient temperatures (Scesny 2006 Layne2009 Doty et al 2018 Geiser et al 2018) Nonethelessbats in both Kentucky and Florida evacuated their roostswithin approximately 10 min after prescribed fires wereset nearby (Dickinson et al 2009 Jorge et al 2021)However the temperatures under which these field ex-periments took place were warmer than the laboratoryexperiments These few examples suggest that bats mayexperience significant mortality from high-intensity fast-moving fires if they are not able to arouse in time to es-cape Because bats are most likely to be in torpor duringmorning (eg Klug and Barclay 2013) it has been sug-gested that prescribed fires be set later in the day whenthey are more likely to respond to audio and olfactory

cues (Layne 2009 Doty et al 2018) Because controllingthe timing of wildfires is not possible risks of mortalityfrom wildfires may be greater than those from pre-scribed fire

Regional variability in the relationships between bats andfireOur literature search did not reveal any studies investi-gating relationships between bats and fire within Asia orthe Indo-Pacific and only two empirical studies in theNeotropics two empirical studies in Europe and onestudy in Africa (Fig 2A) Africa and Asia contain vastareas that experience frequent fires (Archibald et al2013) and increasing fire seasons are predicted with glo-bal climate change (Jolly et al 2015) Additionally firehas been identified as a risk factor to the speciose batcommunities of both regions (Suyanto and Struebig2007 Edirisinghe et al 2018 McCleery et al 2018) Theonly study that has investigated the relationship betweenbats and fire in Africa was based on speciesrsquo range mapsrather than direct observations (Beale et al 2018) It isof considerable importance to global bat conservation tosupport local efforts to study relationships in theseunderstudied regions as they constitute a large propor-tion of global bat diversityThe Neotropics contain the highest number of mam-

malian species in the world including a highly rich batfauna (Burgin et al 2018) Fire is important in manyneotropical ecosystems but is also an increasing threatin many regions due to increasing incidents of drought(Aragatildeo et al 2018) Further 63 of the Neotropics con-sist of fire-sensitive ecosystems (defined as ecosystemswhere most of the organisms have not evolved in thepresence of fire Shlisky et al 2007) Thus understand-ing the response of bats to fire is critical to conservationof this highly diverse fauna To date only two studieshave investigated the relationship between bats and firein the Neotropics (de Oliveira and Aguiar 2015 Santoset al 2021) with somewhat conflicting results It is notclear why so few studies have examined the effects offire on bats in the Neotropics as many studies have ex-amined the effects of logging and deforestation on neo-tropical bats (Meyer et al 2016) However due toincreasing droughts accompanying climate change firesare likely to play a greater role in the ecology and con-servation of neotropical bats and the need for more re-search on its effects is neededIn the Mediterranean region of Europe wildfires burn

frequently and are a key driver of the rapid conversionof forest to shrubland (San-Miguel-Ayanz et al 2012)Additionally megafires are becoming more frequent inthe region due to climate change and land use changessuch as movement of people into fire-prone areas intro-duction of fire-prone invasive species and establishment

of plantations of highly flammable tree species (Moreiraet al 2020) Model-based assessments in the region indi-cate that such fires can significantly reduce and fragmentthe habitat of entire bat communities (Bosso et al 2018)The two recent empirical studies in the region have indi-cated that high-frequency fires can restrict movementsof a clutter-tolerant bat species (Loacutepez-Baucells et al2021) and high-severity wildfire can lead to reducedreproduction and lower body condition in the short term(Ancillotto et al 2020)In Australia there are roughly equal numbers of stud-

ies investigating prescribed and wildfire (Fig 1B)Australia is the most fire-prone of all continents (Mur-phy et al 2019) and though certain ecosystems areadapted to fire Australian wildfire events have been in-creasing in size and severity most notably the 2019ndash2020 fire season which burned 58 million ha of temper-ate broadleaf forests (Boer et al 2020) Australia also hasa long history of prescribed burning which has beenpracticed by Indigenous Australians for many genera-tions to increase landscape productivity to assist hunt-ing and for cultural reasons (eg Yibarbuk et al 2001)Australian studies concerning bats and fire range fromthe temperate southeast to the southwest which is char-acterized by a Mediterranean climate to the tropicalnorth Studies across regions using prescribed firemostly show positive responses by bats with mostly posi-tive to neutral responses to wildfire However only onestudy examined the influence of fire on bat roostinghabitat (Burgar et al 2015) and more research is neededto understand the trade-offs between roost creation anddestruction as a result of fire (Parnaby et al 2010) Nostudies have examined the influence of fire on the twobat species of New Zealand which compared toAustralia has historically less frequent fires a shorterhistory of fire management and fewer fire-adapted plantcommunities (Perry et al 2014 Baillie and Bayne 2019)Although the greatest number of studies on bat re-

sponses to fire have been conducted in North America(Figs 1B and 2A) there are large regional differences inour knowledge of bat responses to prescribed fire versuswildfire For example to date no studies have been pub-lished on bat responses to prescribed fires in westernNorth America and although there are many publishedstudies on responses of bats to prescribed fire in easternNorth America there is only one study of responses towildfire This dichotomy is in part due to the relativelack of prescribed fire being conducted in the westernUSA compared to the eastern USA (Kolden 2019) How-ever due to differences in climate topography foresttypes and fire seasons responses of bats to both pre-scribed fire and wildfire may vary across geographicaland ecological regions Prescribed fires are usually con-ducted during winter spring and fall in eastern North

America and during spring and fall in western NorthAmerica (Ryan et al 2013) These time periods may ormay not align with the historic fire season which vary byregion Further wildfire seasons differ between the eastand west While winter is the season with the greatestprobability of wildfire in eastern North America thegreatest risk of wildfire in western North America isduring late spring summer and fall (Short 2017 Fig 4)As bats insects and flora are at different stages of theirlife cycles when both prescribed fires and wildfire occurin the various geographical regions of North Americathe responses of bats are likely to be different based ontheir phenology Thus predictions based on results ofstudies conducted in one region may not apply in otherregions Further extrapolating from North America toother parts of the world could also be problematic

Understudied bat taxaThe majority of research concerning bats and fire has in-volved two widespread families of bats the Vespertilioni-dae and to a lesser degree the Molossidae As notedabove very little research has been conducted in theNeotropics and therefore the highly diverse Phyllosto-midae family has been understudied Phyllostomid batsplay key roles in forest regeneration due to the high di-versity of seed dispersers (frugivores) and pollinators(nectarivores) in this group Therefore they are likely tocontribute to post-fire vegetation recovery in the region(de Oliveira and Aguiar 2015) While our review focusedon echolocating bats Old World fruit bats are anotherunderstudied group of bats who are impacted by fireFire can trigger dispersal or fragmentation of fruit batcolonies in the short or long term via modification anddestruction of colonial roosting sites (Jenkins et al 2007Baranowski et al 2021) Furthermore fire can greatlyimpact availability of seasonal nectar and fruit resources(Law et al 2000) For example during the 2019ndash2020Australian bushfires 337 of grey-headed flying fox(Pteropus poliocephalus [Temminck]) habitat areaburned including areas of critical winter foraging habitat(Baranowski et al 2021)

Effects of fire on roosts and roosting habitatRoosts are critical for bat survival and reproduction andmore than one-half of all bats use trees or other plantstructures as roosts (Kunz and Lumsden 2003) Fire hasthe potential to significantly affect the availability andquality of roosts and roosting habitat and consequentlybat populations However fewer than one-quarter of thestudies we found examined the roosting responses ofbats to fire and only three examined the roosting re-sponses of bats to wildfire or its severity (Schwab 2006Snider et al 2013 Saunders 2015) Snags are importantroost structures for a number of bat species and both

wildfires and prescribed fires can affect the availability ofsnags (Horton and Mannan 1988 Stephens andMoghaddas 2005 Holden et al 2006 Bagne et al 2008Parnaby et al 2010) Little information is available onthe effects of either prescribed fire or wildfire on charac-teristics of snags that determine their suitability as batroosts such as the presence and amount of bark snagheight and placement on the landscape However a re-cent study on the effects of prescribed fire frequencyfound that the density of snags suitable for bat roosting(defined as pine snags ge 15 cm diameter at breast height)is not affected by fire frequency (Baldwin 2019) Under-standing batsrsquo roost use and selection after wildfire andhow those habitats relate to foraging habitat is critical tofully understanding the short- and long-term effects ofwildfire on bats

The influence of climate change on relationships betweenbats and fireChanging climates along with changes in land use his-tory and management practices are significantly influen-cing the frequency severity and extent of wildfiresacross the globe (Westerling et al 2006 Dennison et al2014 Jolly et al 2015 Abram et al 2021) Warming cli-mates and increased probability of drought may also de-crease the ability to conduct prescribed fire (Kupferet al 2020) further increasing the probability of wildfires

(Fernandes and Botelho 2003 Kalies and Yocom Kent2016) It is unclear how the interaction between in-creased fire frequency fire severity and fire extent willaffect bats at local and landscape scales For examplemore than 23 of the temperate forest of southeastAustralia (~ 65 million ha) burned during the 2019ndash2020 megafires (Abram et al 2021) and fires of this se-verity and extent may have larger impacts on bats andtheir habitats including mortality than the wildfiresreviewed here Since frequent and high-severity firesfavor bats with traits associated with open and edge hab-itats current wildfire trends in fire-prone forests couldlead to bat community shifts with reductions in clutter-tolerant species (Blakey et al 2019) Further becausewildfire seasons are beginning earlier and lasting longerthere is greater probability that fires will occur duringbatsrsquo reproductive period Other effects of climatechange such as drought may interact with increasingwildfire risk to exacerbate negative effects on bats (Pic-cioli Cappelli et al 2021) Drought significantly impactsreproductive success of bats in arid regions (Adams2010) and in many areas of the world and increased firepotential (Fig 2) may coincide with increasing drought(Dai 2012) putting further strain on bat populationsA decrease in the number of suitable days for pre-

scribed fires due to increasing temperatures and droughtduring prescribed fire seasons could have significant

Fig 4 Monthly fire outlooks for the continental USA based on fire density (fires per unit area) averaged over 1999ndash2010 based on data from thespatial wildfire occurrence database ranging from high density (red) to low (yellow) (Short 2017 National Interagency Fire Center 2021)

impacts on maintenance and restoration of habitat forsome species For example the endangered Indiana bat(M sodalis) relies on yellow pines (Pinus subgenusDiploxylon) as their primary roosts in the Southern Ap-palachian Mountains (Britzke et al 2003 OKeefe andLoeb 2017) which are dependent on fire for their per-sistence (Lafon et al 2007) The inability to conduct pre-scribed fires could prevent restoration of critical habitatfor this species Because prescribed fire appears to im-prove foraging habitat for many species decreasing theamount of prescribed fire may decrease the amount ofsuitable foraging habitat for some species While thin-ning may be a suitable fire surrogate for improving batforaging habitat structure (Humes et al 1999 Blakeyet al 2016 Gonsalves et al 2018a 2018b) potential ben-efits to roosting structures from thinning are likely totake decades to develop and effects of thinning on batroosting may be negative in the short term (Loeb 2020)

Conclusions and management implicationsThis review highlighted the complex nature of the rela-tionships between bats and fire whether those fires areprescribed or wildland Because bats appear to showpositive or neutral responses to prescribed fire pre-scribed fire may be an important management tool forbat habitat management as well as restoration of habitatfor other species control of invasive species and reduc-tion in the intensity and extent of wildfires In contrastnegative responses are more prevalent in response towildfire However some of these negative responses areshort-lived perhaps due to batsrsquo vagility and factors suchas fire timing extent and severity Thus we suggest thatfocusing on characteristics of fires (eg burn extent se-verity frequency) across landscapes over space and timemay be more informative than focusing on the presenceof fire and its typeWhile some general patterns emerged from our re-

view many questions remain unanswered This is in partdue to the necessity of taking advantage of opportunitiesas they arise (eg wildfires) the lack of truly replicatedstudies and the wide variation in ecosystems and studyapproaches that are represented in the studies includedin this review Further most studies of bats are con-ducted over relatively short time scales substitutingspace for time (Law and Blakey 2021) As several studiesin this review pointed out responses of bats to fire maychange over time Thus future studies need to be con-ducted over long enough time periods to detect thesechanges Many of the studies reviewed here relied on theuse of acoustic detectors to measure responses of bats tofire If the probability of detecting bats with detectors isrelated to treatments (eg burn versus no burn burn se-verity) then the data may be biased (eg Burns et al2019) Other biases and caveats described by Loeb

(2020) for studies on batsrsquo responses to silviculturaltreatments such as the assumption that greater activitymeans better habitat and restriction of studies to thesummer months apply to studies of batsrsquo responses tofire Further acoustic studies only measure habitat useAs with silvicultural treatments we know little about thephysiological and demographic responses of bats to ei-ther prescribed fire or wildfire (Loeb 2020) Demo-graphic responses including population genetic effectsare particularly important for determining population-level effects and understanding the long-term and large-scale impacts of fire on the status and management ofbats (eg Brown et al 2009) Thus we suggest that fu-ture studies strive to address specific hypotheses aboutpopulation-level responses of bats to fire as has beendone for other silvicultural treatments (Law et al2018a)Our review also highlights the importance of burn pa-

rameters in assessing firersquos impact on bats Many ofthese parameters are interrelated and must be addressedin tandem One way to do this is to further explore theconcept of pyrodiversity and its utility for understandingbatsrsquo response to fire at a range of spatial and temporalscales While questions remain about how to manage foror even quantify pyrodiversity (Jones and Tingley InPress) a range of long-used (indigenous fire manage-ment) and emerging (pyrosilviculture) approaches maybe used to restore and maintain pyrodiversity in land-scapes where it is beneficial to bats and other biodiver-sity (Kelley et al 2020 North et al In Press) Taking anadaptative management approach to both prescribed fireand managed wildfire could provide an avenue to furtherour understanding of how the different properties andconfigurations of fire influence biodiversity with atten-tion to spatial and temporal scales (Driscoll et al 2010Van Wilgen et al 2014 Kelley et al 2020)

Supplementary InformationThe online version contains supplementary material available at httpsdoiorg101186s42408-021-00109-0

Additional file 1 Responses bats to the presence of prescribed fire inAustralian and North American forests Responses were categorized aspositive neutral or negative based on relative activity occupancy orselection of sites in burned areas Guilds for individual species wereassigned based on the literature (Closed- [C] Edge- [E] and Open-Space[O] foragers)

Additional file 2 Responses of bats to the presence of wildfire inAustralian European and North American forests Responses werecategorized as positive neutral or negative based on relative activityoccupancy or selection of sites in burned areas Guilds for individualspecies were assigned based on the literature (Closed- [C] Edge- [E] andOpen-Space [O] foragers)

Additional file 3 Responses of bats to various prescribed fireparameters in Australian and North American forests Responses werecategorized as positive neutral or negative based on relative activityoccupancy or selection of sites in burned areas Guilds for individual

species were assigned based on the literature Guilds for individualspecies were assigned based on the literature (Closed- [C] Edge- [E] andOpen-Space [O] foragers)

Additional file 4 Responses of bats to various wildfire parameters inAustralian Africa Brazilian European and North American forestsResponses were categorized as positive neutral or negative based onrelative activity occupancy or selection of sites in burned areas Guildsfor individual species were assigned based on the literature Guilds forindividual species were assigned based on the literature (Closed- [C]Edge- [E] and Open-Space [O] foragers)

AcknowledgementsThis manuscript was conceptualized after discussions during the Wildfire andPrescribed Fire Effects on Wildlife in US Forests Symposium at the 2020 WildlifeSociety Annual Conference We thank David M J S Bowman and TAbatzolglou for providing the data and allowing reproduction of Fig 2 andthree anonymous reviewers for helpful comments on previous drafts Thefindings and conclusions in this publication are those of the authors andshould not be construed to represent any official USDA or US Governmentdetermination or policy

Authorsrsquo contributionsThe paper was conceived and framed by SC Loeb Both authors conductedseparate literature searches and combined results SC Loeb and RV Blakeyeach wrote sections of the manuscript and jointly edited and approved it

Author informationS C Loeb is a Research Ecologist R V Blakey is a Postdoctoral Fellow

FundingS C Loeb was supported by the US Forest Service Southern ResearchStation and RV Blakey was supported by the La Kretz Center for CaliforniaConservation Science at the University of California Los Angeles

Availability of data and materialsNo data were presented in this paper All papers included in the review arelisted in the Additional Files

Declarations

Ethics approval and consent to participateNot applicable

Consent for publicationDavid M J S Bowman and T Abatzolglou granted permission to use basedata layers in Fig 2 from Bowman et al (2020)

Competing interestsThe authors declare no conflict of interest

Author details1US Forest Service Southern Research Station 233 Lehotsky Hall ClemsonUniversity Clemson SC 29634 USA 2La Kretz Center for CaliforniaConservation Science Institute of the Environment and SustainabilityUniversity of California Los Angeles CA 90095 USA

Received 17 March 2021 Accepted 12 July 2021

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Sharples RH Nolan T Zhang MJ Wooster JB Wurtzel KJ Meissner AJPitman AM Ukkola BP Murphy NJ Tapper and MM Boer 2021Connections of climate change and variability to large and extreme forestfires in southeast Australia Communications Earth and Environment 2 (1) 8httpsdoiorg101038s43247-020-00065-8

Adams RA 2010 Bat reproduction declines when conditions mimic climatechange projections for western North America Ecology 91 (8) 2437ndash2445httpsdoiorg10189009-00911

Aldridge HDJN and IL Rautenbach 1987 Morphology echolocation andresource partitioning in insectivorous bats Journal of Animal Ecology 56 (3)763ndash778 httpsdoiorg1023074947

Ancillotto L L Bosso P Conti and D Russo 2020 Resilient responses by bats toa severe wildfire conservation implications Animal Conservation httpsdoiorg101111acv12653 24 (3) 470ndash481

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Archibald S CER Lehmann JL Goacutemez-Dans and RA Bradstock 2013 Definingpyromes and global syndromes of fire regimes Proceedings NationalAcademy of Science 110 (16) 6442ndash6447 httpsdoiorg101073pnas1211466110

Armitage DW and HK Ober 2012 The effects of prescribed fire on batcommunities in the longleaf pine sandhills ecosystem Journal ofMammalogy 93 (1) 102ndash114 httpsdoiorg10164411-MAMM-A-1691

Arthur MA JM Varner CW Lafon HD Alexander DC Dey CA Harper SP HornTF Hutchinson TL Keyser MA Lashley CE Moorman and CJ Schweitzer2021 Fire ecology and management in eastern broadleaf and Appalchianforests In Fire ecology and management across US forests Past present andfuture ed CH Greenberg and BS Collins 105ndash147 Switzerland Springer

Austin LV A Silvis WM Ford M Mthersbaugh and KE Powers 2018a Batactivity following restoration prescribed burning in the central Appalachianupland and riparian habitats Natural Areas Journal 38 (2) 183ndash195 httpsdoiorg1033750430380208

Austin LV A Silvis WM Ford and KE Powers 2020 Effects of historic wildfireand prescribed fire on site occupancy of bats in Shenandoah National ParkVirginia USA Journal of Forest Research 31 (4) 1255ndash1270 httpsdoiorg101007s11676-019-00923-y

Austin LV A Silvis MS Muthersbaugh KE Powers and WM Ford 2018b Batactivity following repeated prescribed fire in the central Appalachians USAFire Ecology 14 10 httpsdoiorg101186s42408-018-0009-5

Bagne KE KL Purcell and JT Rotenberry 2008 Prescribed fire snag populationdynamics and avian nest site selection Forest Ecology and Management 255(1) 99ndash105 httpsdoiorg101016jforeco200708024

Baillie BR and KM Bayne 2019 The historical use of fire as a land managementtool in New Zealand and the challenges for its continued use LandscapeEcology 34 (10) 2229ndash2244 httpsdoiorg101007s10980-019-00906-8

Baldwin ME 2019 Prescribed fire effects on snags in the southern AppalachianMountains 53 M S Thesis University of West Georgia Carollton GA

Baranowski K CL Faust P Eby and N Bharti 2021 Quantifying the impacts ofAustralian bushfires on native forests and gray-headed flying foxes Global Ecologyand Conservation 27 e01566 httpsdoiorg101016jgecco2021e01566

Beale CM CJ Courtney Mustaphi TA Morrison S Archibald TM Anderson APDobson JE Donaldson GP Hempson J Probert and CL Parr 2018Pyrodiversity interacts with rainfall to increase bird and mammal richness inAfrican savannas Ecology Letters 21 (4) 557ndash567 httpsdoiorg101111ele12921

Best TL and KN Geluso 2003 Summer foraging range of Mexican free-tailedbats (Tadarida brasiliensis mexicana) from Carlsbad Cavern New MexicoSouthwestern Naturalist 48 (4) 590ndash596 httpsdoiorg1018940038-49092003)048lt0590SFROMFgt20CO2

Blakey RV BS Law RT Kingsford J Stoklosa P Tap and K Williamson 2016Bat communities respond positively to large-scale thinning of forestregrowth Journal of Applied Ecology 53 (6) 1694ndash1703 httpsdoiorg1011111365-266412691

Blakey RV EB Webb DC Kesler RB Siegel D Corcoran JS Cole and MJohnson 2021 Extent configuration and diversity of burned and forestedareas predict bat richness in a fire-maintained forest Landscape Ecology 36(4) 1101ndash1115 httpsdoiorg101007s10980-021-01204-y

Blakey RV EB Webb DC Kesler RB Siegel D Corcoran and M Johnson 2019Bats in a changing landscape Linking occupancy and traits of a diversemontane bat community to fire regime Ecology and Evolution 9 (9) 5324ndash5337 httpsdoiorg101002ece35121

Blanco CM and J Garrie 2020 Species specific effects of prescribed burns onbat occupancy in northwest Arkansas Forest Ecology and Management 460117890 httpsdoiorg101016jforeco2020117890

Boer MM V Resco de Dios and RA Bradstock 2020 Unprecedented burn areaof Australian mega forest fires Nature Climate Change 10 (3) 171ndash172httpsdoiorg101038s41558-020-0716-1

Bosso L L Ancillotto S Smeraldo S DArco A Migliozzi P Conti and D Russo2018 Loss of potential bat habitat following a severe wildfire a model-basedrapid assessment International Journal of Wildland Fire 27 (11) 756ndash769httpsdoiorg101071WF18072

Bowman DMJS CA Kolden JT Abatzoglou FH Johnston GR van der Werfand M Flannigan 2020 Vegetation fires in the Anthropocene Nature ReviewsEarth and Environmment 1 (10) 500ndash5115 httpsdoiorg101038s43017-020-0085-3

Boyles JG and DP Aubrey 2006 Managing forests with prescribed fireImplications for a cavity-dwelling bat species Forest Ecology andManagement 222 (1-3) 108ndash115 httpsdoiorg101016jforeco200509024

Braun de Torrez E HK Ober and RA McCleery 2018a Activity of anendangered bat increases immediately following prescribed fire Journal ofWildlife Management 82 (6) 1115ndash1123 httpsdoiorg101002jwmg21481

Braun de Torrez E HK Ober and RA McCleery 2018b Restoring historical fireregimes increases activity of endangered bats Fire Ecology 14 (2) 9 httpsdoiorg101186s42408-018-0006-8

Britzke ER MJ Harvey and SC Loeb 2003 Indiana bat Myotis sodalis maternityroosts in the southern United States Southeastern Naturalist 2 235ndash242httpsdoiorg1016561528-7092(2003)002[0235IBMSMR]20CO2

Broken-Brow J AT Hitch KN Armstrong and LK-P Leung 2020 Effect of fireon insectivorous bat activity in northern Australia does fire intensity matteron a local scale Australian Journal of Zoology 67 (6) 260ndash268 httpsdoiorg101071ZO20030

Brown S M Clarke and R Clarke 2009 Fire is a key element in the landscape-scale habitat requirements and global population status of a threatened birdThe Mallee Emu-wren (Stipiturus mallee) Biological Conservation 142 (2) 432ndash445 httpsdoiorg101016jbiocon200811005

Buchalski MR JB Fontaine PA Heady III JP Hayes and WF Frick 2013 Batresponse to differing fire severity in mixed-conifer forest California USA PLoSOne 8 (3) e57884 httpsdoiorg101371journalpone0057884

Burgar JM MD Craig and VL Stokes 2015 The importance of mature forest asbat roosting habitat within a production landscape Forest Ecology andManagement 356 112ndash123 httpsdoiorg101016jforeco201507027

Burgin CJ JP Colella PL Kahn and NS Upham 2018 How many species ofmammals are there Journal of Mammalogy 99 (1) 1ndash14 httpsdoiorg101093jmammalgyx147

Burns LKL SC Loeb and WC Bridges Jr 2019 Effects of fire and its severity onoccupancy of bats in mixed pine-oak forests Forest Ecology and Management446 151ndash163 httpsdoiorg101016jforeco201905024

Carter TC WM Ford and MA Menzel 2002 Fire and bats in the Southeast andmid-Atlantic more questions than answers In The Role of Fire in NongameWildlife Management and Community Restoration Traditional Uses and NewDirections Proceedings of a Special Workshop 139ndash143 US Department ofAgriculture Forest Service Northeastern Research Station General TechnicalReport NE-128

Chambers CL MJ Herder K Yasuda DG Mikesic SM Dewhurst WM Mastersand D Vleck 2011 Roosts and home ranges of spotted bats (Eudermamaculatum) in northern Arizona Canadian Journal of Zoology 89 (12) 1256ndash1267 httpsdoiorge101139Z11-106

Chiodi AM NS Larkin and JM Varner 2018 An analysis of Southeastern USprescribed burn weather windows seasonal variability and El Nintildeoassociations International Journal of Wildland Fire 27 (3) 176ndash189 httpsdoiorg101071WF17132

Cox MR EV Willcox PD Keyser and AL Vander Yacht 2016 Bat response toprescribed fire and overstory thinning in hardwood forest on theCumberland Plateau Tennessee Forest Ecology and Management 359 221ndash231 httpsdoiorg101016jforeco201509048

Dai A 2012 Increasing drought under global warming in observations andmodels Nature Climate Change 3 (1) 52ndash58 httpsdoiorg101038NCLIMATE1633

de Oliveira HF and LMS Aguiar 2015 The response of bats (MammaliaChiroptera) to an incidental fire on a gallery forest at a Neotropical savannaBiota Neotropica 15 (4) endash0091 httpsdoiorg1015901676-0611-BN-2015-0091

Dennison PE SC Brewe JD Arnold and MA Moritz 2014 Large wildfire trendsin the western United States 1984ndash2011 Geophyscial Research Letters 41 (8)2928ndash2933 httpsdoiorg1010022014GL059576

Dey DC and JM Kabrick 2015 Restoration of midwestern oak woodlands andsavannas In Restoration of boreal and temperate forests ed JA Stanturf 2nded 401ndash428 Boca Raton CRC Press httpsdoiorg101201b18809

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Dickinson MB JC Norris AS Bova RL Kremens V Young and MJ Lacki 2010Effects of wildland fire smoke on a tree-roosting bat integrating a plumemodel field measurements and mammalian dose-response relationshipsCanadian Journal of Forest Research 40 (11) 2187ndash2203 httpsdoiorg101139X10-148

Doty AC SE Currie C Stawski and F Geiser 2018 Can bats sense smokeduring deep torpor Physiology and Behavior 185 31ndash38 httpsdoiorg101016jphysbeh201712019

Doty AC C Stawski BS Law and F Geiser 2016 Post-wildfire physiologicalecology of an Australian microbat Journal of Comparative Physiology B 186(7) 937ndash946 httpsdoiorg101007s00360-016-1003-3

Driscoll DA DB Lindenmayer AF Bennett M Bode RA Bradstock GJ Cary MF Clarke N Dexter R Fensham G Friend M Gill S James G Kay DA KeithC MacGregor J Russell-Smith D Salt JEM Watson RJ Williams and AYork 2010 Fire management for biodiversity conservation Key researchquestions and our capacity to answer them Biological Conservation 143 (9)1928ndash1939 httpsdoiorg101016jbiocon201005026

Edirisinghe G T Surasinghe D Gabadage M Botejue K Perera M Madawala DWeerakoon and S Karunarathna 2018 Chiropteran diversity in the peripheral areasof the Maduru-Oya National Park in Sri Lanka Insights for conservation andmanagement Zookeys 784 (784) 139ndash162 httpsdoiorg103897zookeys78425562

Fenton MB 1990 The foraging behaviour and ecology of animal-eating batsCanadian Journal of Zoology 68 (3) 411ndash422 httpsdoiorg101139z90-061

Fernandes PM and HS Botelho 2003 A review of prescribed burningeffectiveness in fire hazard reduction International Journal of Wildland Fire 12(2) 117ndash128 httpsdoiorg101071WF02042

Frick WF T Kingston and J Flanders 2020 A review of the major threats andchallenges to global bat conservation Annals of New York Academy ofScience 1469 (1) 5ndash25 httpsdoiorg101111nyas14045

Geiser F C Stawski AC Doty CE Cooper and J Nowak 2018 A burningquestion what are the risks and benefits of mammalian torpor during andafter fires Conservation Physiology 6 (1) coy057 httpsdoiorg101093conphyscoy057

Gonsalves L B Law and R Blakey 2018a Experimental evaluation of the initialeffects of large-scale thinning on structure and biodiversity of river red gum(Eucalyptus camaldulensis) forests Wildlife Research 45 (5) 397ndash410 httpsdoiorg101071WR17168

Gonsalves L B Law T Brassil C Waters I Toole and P Tap 2018b Ecologicaloutcomes for multiple taxa from silvicultural thinning of regrowth forestForest Ecology and Management 425 177ndash188 httpsdoiorg101016jforeco201805026

Greenberg CH and BS Collins 2021 Fire ecology and management across USforests Past present and future 502 Switzerland Springer

Griffitts R 2016 Assessing the effects of prescribed fire on foraging bats atMammoth Cave National Park after the arrival of white-nose syndrome MSthesis Richmond University of Eastern Kentucky

Holden ZA P Morgan MG Rollins and RG Wright 2006 Ponderosa pine snagdensities following multiple fires in the Gila Wilderness New Mexico ForestEcology and Management 221 (1-3) 140ndash146 httpsdoiorg101016jforeco200509014

Horton SP and RW Mannan 1988 Effects of prescribed fire on snags andcavity-nesting birds in southeastern Arizona pine forests Wildlife SocietyBulletin 16 37ndash44

Hovick TJ DA McGranahan RD Elmore JR Weir and SD Fuhlendorf 2017Pyric-carnivory Raptor use of prescribed fires Ecology and Evolution 7 (21)9144ndash9150 httpsdoiorg101002ece33401

Humes ML JP Hayes and MW Collopy 1999 Bat activity in thinnedunthinned and old-growth forests in western Oregon Journal of WildlifeManagement 63 (2) 553ndash561 httpsdoiorg1023073802642

Hunter ME and MD Robles 2020 Tamm review The effects of prescribed fireon wildfire regimes and impacts A framework for comparison Forest Ecologyand Management 475 118435 httpsdoiorg101016jforeco2020118435

Inkster-Draper TE M Sheaves CN Johnson and SKA Robson 2013 Prescribedfire in eucalypt woodlands immediate effects on a microbat community of

northern Australia Wildlife Research 40 (1) 70ndash76 httpsdoiorg101071WR12133

IUCN 2020 The IUCN red list of threatened species wwwiucnredlistorgAccessed 29 Dec 2020

Jemison M L Lumsden J Nelson M Scroggie and R Chick 2012 Assessing theimpact of the 2009 Kilmore East-Murrindindi Complex fire on microbatsHeidelberg Department of Sustainability and Environment

Jenkins RKB D Andriafidison HJ Razafimanahaka A Rabearivelo NRazafindrakoto Z Ratsimandresy RH Andrianandrasana E Razafimahatratraand PA Racey 2007 Not rare but threatened the endemic Madagascarflying fox Pteropus rufus in a fragmented landscape Oryx 41 (2) 263ndash271httpsdoiorg101017S0030605307001883

Johnson JB JW Edwards WM Ford and JE Gates 2009 Roost tree selectionby northern myotis (Myotis septentrionalis) maternity colonies followingprescribed fire in a Central Appalachian Mountains hardwood forest ForestEcology and Management 258 (3) 233ndash242 httpsdoiorg101016jforeco200904008

Johnson JB WM Ford JL Rodrigue JW Edwards and CM Johnson 2010Roost selection by male Indiana myotis following forest fires in CentralAppalachian Hardwoods forests Journal of Fish and Wildlife Management 1(2) 111ndash121 httpsdoiorg103996042010-JFWM-007

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Jones GM and MW Tingley In Press Pyrodiversity and biodiversity A historysynthesis and outlook Diversity and Distributions httpsdoiorg101111ddi13280

Jorge MH WM Ford SE Sweeten SR Freeze MC True MJSt Germaine HTaylor KM Gorman EP Garrison and MJ Cherry 2021 Winter roostselection of Lasiurine tree bats in a pyric landscape PLoS One 16 (2)e0245695 httpsdoiorg101371journalpone0245695

Kalies EL and LL Yocom Kent 2016 Tamm Review Are fuel treatmentseffective at achieving ecological and social objectives A systematic reviewForest Ecology and Management 375 84ndash95 httpsdoiorg101016jforeco201605021

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Kelley LT KM Giljohann A Duane N Aquilueacute S Archibald E Batllori AF BennettST Buckland Q Canelles MF Clarke M-J Fortin V Hermoso S Herrando REKeane FK Lake MA McCarthy A Moraacuten-Ordoacutentildeez CL Parr JG Pausas TDPenman A Regos L Rumpff JL Santos AL Smith AD Syphard MW Tingleyand L Brotons 2020 Fire and biodiversity in the Anthropocene Science 370eabb0355 httpsdoiorg101126scienceabb0355

Klug BJ and RMR Barclay 2013 Thermoregulation during reproduction in thesolitary foliage-roosting hoary bat (Lasiurus cinereus) Journal of Mammalogy94 (2) 477ndash487 httpsdoiorg10164412-MAMM-A-1781

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Kolden CA 2019 Wersquore not doing enough prescribed fire in the Western UnitedStates to mitigate wildfire risk Fire 2 (2) 30 httpsdoiorg103390fire2020030

Kunz TH and LF Lumsden 2003 Ecology of cavity and foliage roosting bats InBat ecology ed TH Kunz and MB Fenton 3ndash89 Chicago The University ofChicago Press

Kupfer JA AJ Terando P Gao C Teske and JK Hiers 2020 Climate changeprojected to reduce prescribed burning opportunities in the south-easternUnited States International Journal of Wildland Fire 29 (9) 764ndash778 httpsdoiorg101071WF19198

Lacki MJ DR Cox LE Dodd and MB Dickinson 2009 Response of northernbats (Myotis septentrionalis) to presribed fires in eastern Kentucky forestsJournal of Mammalogy 90 (5) 1165ndash1175 httpsdoiorg10164408-MAMM-A-3491

Lacki MJ LE Dodd NS Skowronski MB Dickinson and LK Rieske 2017Relationships among burn severity forest canopy structure and bat activityfrom spring burns in oakndashhickory forests International Journal of Wildland Fire26 (11) 963ndash972 httpsdoiorg101071WF16159

Lafon CW JD Waldron DM Cairns MD Tchakerian RN Coulson and KDKlepzig 2007 Modeling the effects of fire on the long-term dynamics andrestoration of the yellow pine and oak forests in the southern AppalachianMountains Restoration Ecology 15 (3) 400ndash411 httpsdoiorg101111j1526-100X200700236x

Law B A Doty M Chidel and T Brassil 2018b Bat activity before and after asevere wildfire in Pilliga forests Resilience influenced by fire extent andlandscape mobility Austral Ecology 43 (6) 706ndash718 httpsdoiorg101111aec12617

Law B L Gonsalves A McConville and P Tap 2020 Landscape monitoringreveals initial trends in occupancy and activity of bats in multiple-use forestsAustral Ecology 46 261ndash276 httpsdoiorg101111aec12976

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Law B KJ Park and MJ Lacki 2016 Insectivorous bats and silviculturebalancing timber production and bat conservation In Bats in theAnthropocene conservation of bats in a changing world ed CC Voight and TT Kingston 105ndash150 Heidleberg Springer

Law BS and RV Blakey 2021 Bats in temperate forests Where are the trends inbat populations In 50 Years of bat research Foundations and new frontiersed BK Lim MB Fenton RM Brigham S Mistry A Kurta EH Gillam ARussell and J Ortega 93ndash104 Cham Springer httpsdoiorg101007978-3-030-54727-1_6

Law BS M Chidel and PR Law 2018a Forest bat population dynamics over 14years at a climate refuge Effects of timber harvesting and weather extremesPLoS One 13 (2) e0191471 httpsdoiorg101371journalpone0191471

Layne JT 2009 Eastern red bat (Lasiurus borealis) response to fire stimulus duringtorpor Springfield MS thesis Missouri State University

Loeb SC 2020 Qualitative synthesis of temperate bat responses to silviculturaltreatmentsmdashwhere do we go from here Journal of Mammalogy 101 (6)1513ndash1525 httpsdoiorg101093jmammalgyaa089

Loeb SC and TA Waldrop 2008 Bat activity in relation to fire and fire surrogatetreatments in southern pine stands Forest Ecology and Management 255 (8-9) 3185ndash3192 httpsdoiorg101016jforeco200710060

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McCaw WL 2013 Managing forest fuels using prescribed fire ndash A perspectivefrom southern Australia Forest Ecology and Management 294 217ndash224httpsdoiorg101016jforeco201209012

McCleery R A Monadjem B Baiser R Fletcher K Vickers and L Kruger 2018Animal diversity declines with broad-scale homogenization of canopy coverin African savannas Biological Conservation 226 54ndash62 httpsdoiorg101016jbiocon201807020

Meyer CFJ MJ Struebig and MR Willig 2016 Responses of tropical bats tohabitat fragmentation logging and deforestation In Bats in theAnthropocene conservation of bats in a changing world ed CC Voight and TKingston 63ndash103 Heidleberg Springer httpsdoiorg101007978-3-319-25220-9

Milne DJ M Armstrong A Fisher T Flores and CR Pavey 2005 Structure andenvironmental relationships of insectivorous bat assemblages in tropicalAustralian savannas Austral Ecology 30 (8) 906ndash919 httpsdoiorg101111j1442-9993200501535x

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Moreira F D Ascoli H Safford MA Adams JM Moreno JMC Pereira FXCatry J Armesto W Bond ME Gonzaacutelez T Curt N Koutsias L McCaw OPrice JG Pausas E Rigolot S Stephens C Tavsanoglu VR Vallejo BW VanWilgen G Xanthopoulos and PM Fernandes 2020 Wildfire management inMediterranean-type regions Paradigm change needed EnvironmentalResearch Letters 15 (1) 011001 httpsdoiorg1010881748-9326ab541e

Murphy BP LD Prior MA Cochrane GJ Williamson and DMJS Bowman2019 Biomass consumption by surface fires across Earthrsquos most fire pronecontinent Global Change Biology 25 (1) 254ndash268 httpsdoiorg101111gcb14460

National Interagency Fire Center 2021 National significant wildfire potentialoutlooks httpswwwpredictiveservicesnifcgovoutlooksoutlookshtmAccessed 6 Mar 2021

North MP RA York BM Collins MD Hurteau GM Jones EE Knapp L KobziarH McCann MD Meyer SL Stephens RE Tompkins and CL Tubbesing InPress Pyrosilviculture needed for landscape resilience of dry western UnitedStates forests Journal of Forestry httpsdoiorg101093joforefvab026

OKeefe JM and SC Loeb 2017 Indiana bats roost in ephemeral fire-dependent pine snags in the southern Appalachian Mountains USA ForestEcology and Management 391 264ndash274 httpsdoiorg101016jforeco201701036

OShea TJ PM Cryan DTS Hayman RK Plowright and DG Streicker 2016Multiple mortality events in bats a global review Mammal Review 46 (3)175ndash190 httpsdoiorg101111mam12064

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Perry GLW JM Wilmshurst and MS McGlone 2014 Ecology and long-termhistory of fire in New Zealand New Zealand Journal of Ecology 38 157ndash176

Perry RW 2012 A review of fire effects on bats and bat habitats in the easternoak region In Proceedings of the 4th Fire in Eastern Oak Forests Conference volGTR-NRS-P-102 170ndash191 Springfield Northern Research Station

Perry RW SC Brandebura and TS Risch 2016 Selection of tree roosts by maleIndiana bats during the autumn swarm in the Ozark Highlands USA WildlifeSociety Bulletin 40 (1) 78ndash87 httpsdoiorg101002wsb624

Piccioli Cappelli M RV Blakey D Taylor J Flanders T Badeen S Butts WFFrick and H Rebelo 2021 Limited refugia and high velocity range-shiftspredicted for bat communities in drought-risk areas of the NorthernHemisphere Global Ecology and Conservation 28 301608 httpsdoiorg101016jgecco2021e01608

Russell-Smith J and AC Edwards 2006 Seasonality and fire severity in savannalandscapes of monsoonal northern Australia International Journal of WildlandFire 15 (4) 541ndash550 httpsdoiorg101071WF05111

Ryan KC EE Knapp and JM Varner 2013 Prescribed fire in North Americanforests and woodlands history current practice and challenges Frontiers inEcology and the Environment 11 (s1) e15ndashe24 httpsdoiorg101890120329

San-Miguel-Ayanz J M Rodrigues SS de Oliveira CK Pacheco F Moreira BDuguy and A Camia 2012 Land cover change and fire regime in theEuropean Mediterranean Region In Post-fire management and restoration ofSouthern European Forests ed F Moreira M Arianoutsou P Corona and JDe Las Heras 21ndash43 Switzerland Springer httpsdoiorg101007978-94-007-2208-8_2

Santos CF RC Teixeira J Raizer and E Fischer 2021 Post-fire phyllostomidassemblages in forest patches of the Pantanal wetland Mammalia 85 (2)155ndash158 httpsorcidorg0000-0001-8722-9876 httpsdoiorg101515mammalia-2020-0037

Saunders EH 2015 Bat assemblage and selection of maternity roosts in a post-wildfire landscape MS thesis Flagstaff Northern Arizona University

Scesny AA 2006 Detection of fire by eastern red bats (Lasiurus borealis) Arousalfrom torpor MS thesis Springfield Missouri State University

Schwab NA 2006 Roost-site selection and potential prey sources after wildlandfirefor two insectivorous bat species (Myotis evotis and Myotis lucifugus) in mid-elevation forests of western Montana Missoula MS thesis ArlingtonUniversity of Montana

Senior KL KM Giljohann MA McCarthy FW Rainsford and LT Kelly 2021Predicting mammal responses to pyrodiversity From microbats tomacropods Biological Conservation 256 109031 httpsdoiorg101016jbiocon2021109031

Shlisky A J Waugh P Gonzalez M Gonzalez M Manta H Santoso E Alvarado AAinuddin DA Rodriacuteguez-trejo R Swaty D Schmidt M Kaufmann R Myers AAlencar F Kearns D Johnson J Smith and D Zollner 2007 Fire ecosystems andpeople threats and strategies for global biodiversity conservation 17 The NatureConservancy Global Fire Initiative Technical Report

Short KC 2017 Spatial wildfire occurrence data for the United States 1992-2015[FPA_FOD_20170508] Fort Collins USDA Forest Service Research DataArchive

Silvis A SD Gehrt and RA Williams 2016 Effects of shelterwood harvest andprescribed fire in upland Appalachian hardwood forests on bat activityForest Ecology and Management 360 205ndash212 httpsdoiorg101016jforeco201510010

Smith CK AJ Turner JK Hiers J Garai WN Wilson and AN Nunley 2020 Theeffects of oak (Quercus) restoration on forest trajectory and small mammaluse in the southern Cumberland Plateau USA Fire Ecology 16 (1) 20 httpsdoiorg101186s42408-020-00080-2

Smith DA and SD Gehrt 2010 Bat response to woodland restoration withinurban forest fragments Restoration Ecology 18 (6) 914ndash923 httpsdoiorg101111j1526-100X200900538x

Snider EA PM Cryan and KR Wilson 2013 Roost selection by western long-eared myotis (Myotis evotis) in burned and unburned pinonndashjuniperwoodlands of southwestern Colorado Journal of Mammalogy 94 (3) 640ndash649 httpsdoiorg10164411-MAMM-A-1531

Sommers WT SG Coloff and SG Conard 2011 Synthesis of knowledge Firehistory and climate change 190 Boise Joint Fire Science Program

Starbuck CA SK Amelon and FR Thompson III 2015 Relationships betweenbat cccupancy and habitat and landscape structure along a savannawoodland forest gradient in the Missouri Ozarks Wildlife Society Bulletin 39(1) 20ndash30 httpsdoiorg101002wsb512

Starbuck CA ES Considine and CL Chambers 2020 Water and elevation aremore important than burn severity in predicting bat activity at multiplescales in a post-wildfire landscape PLoS One 15 (4) e0231170 httpsdoiorg101371journalpone0231170

Steel ZL B Campos WF Frick R Burnett and HD Safford 2019 The effects ofwildfire severity and pyrodiversity on bat occupancy and diversity in fire-suppressed forests Scientific Reports 9 (1) 16300 httpsdoiorg101038s41598-019-52875-2

Stephens SL and JJ Moghaddas 2005 Fuel treatment effects on snags andcoarse woody debris in a Sierra Nevada mixed conifer forest Forest Ecologyand Management 214 (1-3) 53ndash64 httpsdoiorg101016jforeco200503055

Suyanto A and MJ Struebig 2007 Bats of the Sangkulirang limestone karstformations East Kalimantan - A priority region for Bornean bat conservationActa Chiropterologica 9 (1) 67ndash95 httpsdoiorg1031611733-5329(2007)9[67BOTSLK]20CO2

Swengel AB 2001 A literature review of insect responses to fire compared toother conservation managements of open habitat Biodiversity andConservation 10 (7) 1141ndash1169 httpsdoiorg101023A1016683807033

Thalken MM and MJ Lacki 2018 Tree roosts of northern long-eared batsfollowing white-nose syndrome Journal of Wildlife Management 82 (3) 629ndash638 httpsdoiorg101002jwmg21411

Thalken MM MJ Lacki and JS Johnson 2018 Shifts in assemblage of foragingfats at Mammoth Cave National Park following arrival of white-nosesyndrome Northeastern Naturalist 25 (2) 202ndash214 httpsdoiorg1016560450250203

Van Wilgen BW N Govender IPJ Smit and S MacFadyen 2014 The ongoingdevelopment of a pragmatic and adaptive fire management policy in a largeAfrican savanna protected area Journal of Environmental Management 132358ndash368 httpsdoiorg101016jjenvman201311003

Waldien DL and JP Hayes 2001 Activity areas of female long-eared myotis inconiferous forests in western Oregon Northwest Science 75 307ndash314

Ward M AIT Tulloch JQ Radford BA Williams AE Reside SL Macdonald HJMayfield M Maron HP Possingham SJ Vine JL OrsquoConnor EJ MassinghamAC Greenville JCZ Woinarski ST Garnett M Lintermans BC Scheele JCarwardine DG Nimmo DB Lindenmayer RM Kooyman JS Simmonds LJ Sonter and JEM Watson 2020 Impact of 2019ndash2020 mega-fires onAustralian fauna habitat Nature Ecology and Evolution 4 (10) 1321ndash1326httpsdoiorg101038s41559-020-1251-1

Westerling AL HG Hidalgo DR Cayan and TW Swetnam 2006 Warming andearlier spring increase Western US forest wildfire activity Science 313 (5789)940ndash943 httpsdoiorg101126science1128834

Willig MR BD Patterson and RD Stevens 2003 Patterns of range size richnessand body size in the Chiroptera In Bat ecology ed TH Kunz and MBFenton 580ndash621 Chicago The University of Chicago Press

Yibarbuk D Whitehead P J Russell-Smith J Jackson D Godjuwa C Fisher ACooke P Choquenot D Bowman D M J S 2001 Fire ecology andAboriginal land management in central Arnhem Land northern Australia atradition of ecosystem management Journal of Biogeography 28(3) 325-343httpsdoiorg101046j1365-2699200100555x

Publisherrsquos NoteSpringer Nature remains neutral with regard to jurisdictional claims inpublished maps and institutional affiliations

Abstract

Background

Results

Conclusions

Resumen

Antecedentes

Resultados

Conclusiones

Introduction

Review approach and available literature

Bat responses to burned versus unburned sites

Effects of fire parameters on batsmdashburn extent

Effects of fire parameters on batsmdashfire frequency time since last burn and fire return interval

Effects of fire parameters on batsmdashburn season

Effects of fire parameters on batsmdashburn severity or intensity

Effects of fire parameters on batsmdashpyrodiversity

Bat responses to firemdashprescribed fire versus wildfire

Knowledge gaps

Bat mortality from fire events

Regional variability in the relationships between bats and fire

Understudied bat taxa

Effects of fire on roosts and roosting habitat

The influence of climate change on relationships between bats and fire

Conclusions and management implications

Supplementary Information

Acknowledgements

Authorsrsquo contributions

Author information

Funding

Availability of data and materials

Declarations

Ethics approval and consent to participate

Consent for publication

Competing interests

Author details

References

Publisherrsquos Note

Resumen

Antecedentes Los murcieacutelagos son importantes componentes de los ecosistemas boscosos y se encuentran entodo el mundo En consecuencia a menudo interactuacutean con el fuego Revisiones previas de los efectos del fuegosobre los murcieacutelagos se han enfocado en los efectos de quemas prescriptas en parte debido al nuacutemero limitadode estudios sobre las respuestas de los murcieacutelagos a los incendios Sin embargo hace ya varios antildeos que estudiosde las respuestas de los murcieacutelagos a los incendios y a las quemas prescriptas se han incrementadoconsiderablemente Revisamos este cuerpo de literatura que se expande raacutepidamente para determinar si losmurcieacutelagos responden en forma diferente a las quemas prescriptas y a los incendios y la importancia de losfactores que producen esas diferencias Tambieacuten examinamos similitudes regionales y diferencias en la respuesta delos murcieacutelagos a las quemas prescriptas e incendios e identificamos aacutereas que necesitan maacutes investigaciones

Resultados Nuestra revisioacuten incluyoacute 52 estudios (29 quemas prescriptas 23 incendios) de Norte y SudameacutericaEuropa Australia y Aacutefrica aunque los estudios de Europa Sudameacuterica y Aacutefrica fueron limitados En generalencontramos que los murcieacutelagos muestran respuestas positivas o neutras a las quemas prescriptas mientras queuna mayor proporcioacuten de respuestas negativas fueron reportadas para incendios No obstante algunas de lasrespuestas negativas a los incendios son de corta duracioacuten o locales sugiriendo que los murcieacutelagos pueden serresilientes a los efectos del fuego Factores como la severidad del fuego la frecuencia del fuego tiempo desde lauacuteltima quema extensioacuten de la quema temporada de la quema y piro-diversidad se encontraron comoimportantes conductores de las respuestas de los murcieacutelagos tanto para quemas prescriptas como para incendios

Conclusiones La importancia de los aspectos espaciales y temporales del fuego sugieren que estos factoresnecesitan ser considerados en el disentildeo de futuros estudios y en la interpretacioacuten de los resultados La piro-diversidad puede ser un concepto particularmente importante para entender mejor las respuestas de losmurcieacutelagos al fuego Encontramos varios huecos en nuestro conocimiento incluyendo falta de informacioacuten de losefectos directos del fuego (por ej mortalidad) desviacuteos taxonoacutemicos y regionales efectos de los incendios en loshaacutebitats de descanso y los efectos del cambio climaacutetico A pesar de que los estudios actuales sugieren que elfuego puede ser una herramienta importante para mejorar el haacutebitat de los murcieacutelagos la amenaza de fuegosmaacutes frecuentes extensos y severos puede agregar un estreacutes adicional en algunas poblaciones de murcieacutelagosparticularmente aqueacutellas que estaacuten siendo impactadas por enfermedades peacuterdida de haacutebitat y fragmentacioacuten ycambio climaacutetico

IntroductionBats are a highly diverse group of mammals varyingbroadly in morphology life history ecology and conser-vation status (Willig et al 2003 Frick et al 2020) Theyare found on every continent except Antarctica and oc-cupy a diversity of habitats ranging from deserts to rain-forests and may be found from the equator to the Arcticas well as in remote urban and agricultural areas Des-pite the diversity of habitats which bats utilize most batspecies rely on forests to some extent as forests providecritical resources for foraging roosting and drinkingwater (Law et al 2016) Because forests throughout theworld often experience fire both natural and human-ignited bats often interact with fireFire may have direct and indirect effects on bats (Perry

2012) Direct effects include immediate mortality as wellas carbon monoxide toxicity and tissue damage such asear burns (Dickinson et al 2010) Fires may also resultin the need to abandon roosts (Moorman et al 1999Dickinson et al 2009 Jorge et al 2021) making batsmore vulnerable to predation Indirect effects resultfrom changes in the habitat and include the creation or

loss of suitable roost sites changes in foraging habitatstructure and changes in the insect prey base (Perry2012) Indirect effects may be positive neutral or nega-tive For example use or activity of some bat species in-creases after prescribed fire or wildfire while that ofother species declines or does not change (eg Inkster-Draper et al 2013 Austin et al 2018a 2018b Law et al2018b Ancillotto et al 2020)Due to the lack of research on bat responses to fire

prior to the early 2000s Carter et al (2002) reviewedsome of the potential effects of prescribed fire on bats inthe eastern USA and developed several hypotheses abouthow fire may affect their roosting and foraging behaviorPerry (2012) provided a more thorough review of the ef-fects of fire on bats in the eastern oak region of theUSA but most of the papers included in his review ex-amined the effects of prescribed fire on bats More re-cently Loeb (2020) synthesized the literature on effectsof silvicultural treatments including regeneration har-vests thinning gap formation plantation forestry andfire on bat activity and habitat use in temperate zoneforests Like Perryrsquos (2012) review most of the fire

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Abstract