Encyclopedia of Caves || Protecting Caves and Cave Life

See Also the Following Article

(Brodar, 1969).

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Brodar, S. (1969). Latest Palaeolithic Discoveries in the PostojnaCaves. Acta Archaeologica, 20, 141�145.

Car, J., & Gospodaric, R. (1984). About geology of karst betweenPostojna, Planina and Cerknica. Acta Carsologica, 12, 93�106.

Gabrovsek, F., Kogovsek, J., Kovacic, G., Petric, M., Ravbar, N., &Turk, J. (2010). Recent results of tracer tests in the catchment ofthe Unica River (SW Slovenia). Acta Carsologica, 39(1), 27�37.

Gospodaric, R. (1976). The Quaternary caves development betweenthe Pivka basin and polje of Planina. Acta Carsologica, 7, 7�13.

Kogovsek, J., & Sebela, S. (2004). Water tracing through the vadosezone above Postojnska Jama, Slovenia. Environmental Geology, 45,992�1001.

Shaw, T. R. (2000). Foreign travellers in the Slovene karst 1537�1900.Ljubljana: ZRC Publishing.

Shaw, T. R. (2010). Aspects of the history of Slovene karst 1545�2008.Ljubljana: ZRC Publishing.

Sebela, S. (1998). Tectonic structure of Postojnska jama cave system (Vol.18, 112 pp.). Ljubljana: ZRC Publishing.

Sebela, S., & Sasowsky, I. D. (1999). Age and magnetism of cave sedi-ments from Postojnska jama cave system and Planinska jamacave, Slovenia. Acta Carsologica, 28, 293�305.

Sebela, S., Vaupotic, J., Kostak, B., & Stemberk, J. (2010). Recent mea-surement of present-day tectonic movement and associated radonflux in Postojna cave, Slovenia. Journal of Cave and Karst Studies,72, 21�34.

Zupan Hajna, N., Mihevc, A., Pruner, P., & Bosak, P. (2008).Palaeomagnetism and magnetostratigraphy of karst sediments inSlovenia. In Carsologica (Vol. 8, 266 pp.). Ljubljana: ZRCPublishing.

PROTECTING CAVES AND CAVE LIFEWilliam R. Elliott

Missouri Department of Conservation

PROTECTING CAVE LIFE

Threats to Cave Life

Caves are often thought of as unchanging environ-ments, but with modern instruments in the farthestreaches of large caves there are detectable, annualchanges in air and water. Some caves are naturallyperturbed by flooding or temperature shifts, and theseevents influence the types of communities found there.

Caves that flood violently usually lack truly cave-adapted species, called troglobites or troglobionts, butmay have troglophiles (cave-loving species) and troglox-enes (animals, such as bats, that roost in caves but exitto feed or migrate). Indiana bats (Myotis sodalis) andgray bats, (Myotis grisescens) hibernate in the near-

freezing zone of certain cold-air-trap caves, whichhave deep or large entrances. Such entrances allowcold air to flow inward during strong cold fronts. Incontrast, in summer gray bats and Mexican free-tailedbats (Tadarida brasiliensis mexicana) prefer warm caveswith high ceiling domes, which, combined with batbody heat, help to create an incubator effect for youngbats in the summer, .30�C in grays and .40�C forfree-tails.

Different animals are adapted to the naturalextremes of caves and other habitats. Human-causedthreats, however, can severely tax the ability of wild-life to adjust. Some of the most destructive changes tocaves were brought about by quarrying and waterprojects that completely destroyed, or flooded caves.Human disturbance of bat roosts caused severedeclines in numerous bat species (Elliott, 2000), butsince 2006 white-nose syndrome (WNS) has killedmore than 1 million bats in the eastern United States.Bats are discussed in more detail below.

Amphibian chytrid fungus, Batrachochytrium dendro-batidis (Bd), was found in southern Missouri caves byRimer and Briggler (2010). This disease has killedmany amphibians worldwide, but this was the firstreport from caves. Eight of 12 caves sampled were pos-itive in all five counties visited. Five of the 7 species ofsalamanders and frogs sampled were positive, with anindividual infection rate of 31%. Chytrid was con-firmed in the grotto salamander (Eurycea spelaea), thefirst report in a troglobite. It is not known if humansspread the chytrid spores into caves, but once in anarea it can spread via groundwater, humans, or pick-erel frogs, which use caves seasonally. Chytrid andWNS in caves point to the need to practice “clean cav-ing” and decontamination as a precaution against thespread of wildlife diseases.

Other pressures on cave life act over long timespans and are more difficult to measure. They includehydrological changes caused by land development,which can alter the normal hydrological cycle andincrease sedimentation. For example, residential devel-opments may cause an increase in nitrogenous wastesand sediments washed into caves. Sediments can beharmful to aquatic creatures with gills and/or softbody tissues, such as cavefishes, salamanders, and“cave snails” (eyeless, subterranean snails).

The enrichment of caves with wastes, such asammonia and other nitrogen-based compounds, ininfiltrating waters, can bring an increase in bacterialgrowth. Bacteria in groundwater are not killed by sun-light and they can be transmitted for many miles.Residential developments may also bring exotic spe-cies, such as the aggressive red imported fire ant,which has caused many problems in caves in Texas(Elliott, 2000).

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Encyclopedia of Caves. © 2012 Elsevier Inc. All rights reserved.

Regional overpumping of wells can lower karstgroundwater to the point where important springs andwells run dry, endangering species that live there andthreatening water sources. In Texas, endangered spe-cies of salamander, amphipod, and wild rice havebeen affected by such trends.

Dramatic chemical spills can harm caves if the con-taminants seep into streams or other routes into thecave. Once chemicals are in the groundwater, they aredifficult to remove. Nutrient loss seems to happen lessfrequently than nutrient enrichment, but can causesevere problems (see example of Shelta Cave, below).

Extinct and Endangered Species

Although about six North American troglobitic spe-cies are thought to be extinct, it is likely that othersbecame extinct before they could be discovered ordescribed. Local populations of invertebrates, fishes,salamanders, and bats have been extirpated. Sincesome troglobitic species are endemic to a single caveor a small cluster of caves, and many caves have beendisturbed, filled, quarried, mined, or polluted, it ispossible that some species have disappeared recentlywithout our knowledge.

Bats

Bats are important contributors to the world’s eco-logical health. Caves harbor numerous bat species,which consume night-flying insects, some of which areagricultural, forest, or public health pests (Clevelandet al., 2006). In Missouri, about 800,000 gray bats,which roost in caves year-round, consume 490 metrictons of insects per year (Missouri Department ofConservation, 2010). In the tropics, bats that eat fruitand pollinate plants often roost in caves. So, eventhough some bats do not use caves, the bat-cave con-nection is important.

Declines in North American cave bats becamenoticeable in the 1950s. Six of the 47 continental U.S.bats are currently on the U.S. endangered species listand additional species have been petitioned for listing.The 6 are dependent on caves for part of their lifecycle, and human disturbance has been the major fac-tor in their decline. For example, Indiana bats (M. soda-lis) lost significant numbers through disturbance oftheir hibernacula and improper gating decades ago. Ifsuch bats cannot hibernate deeply, they use up theirbody fat too fast, which results in starvation or deathbefore spring.

Large water projects can drown caves under reser-voirs, or use them as recharge wells. A recharge proj-ect caused violent flooding of Valdina Farms Sinkhole,

a large cave near San Antonio, Texas. In 1987, a largeflood pulse cleaned out the cave. The cave lost a col-ony of four million Mexican free-tailed bats (Tadaridabrasiliensis mexicana) and a rare colony of ghost-facedbats (Moormoops megalophylla). A salamander (Euryceatroglodytes) which lived only in that cave, probably isextinct as a result.

The mining of caves for saltpeter, bat guano, orother minerals can have a drastic effect on bat coloniesand other fauna. Mexican free-tailed bats have beendisturbed by some guano mining in Texas, while someminers may have aided the colonies by mining outrooms that would have filled with guano. The betteroperations mine only in the winter when the bats aregone. The opening of large, second entrances canseverely alter the meteorology of a cave, causing batsto vacate. Marshall Bat Cave, Texas, lost its free-tailcolony after 1945, when a large, 40-m-deep shaft wasdug into the rear of the cave to hoist out guano, caus-ing too much ventilation and cooling of the cave.

Mammoth Cave once harbored Indiana bats beforethe entrance was modified to block incursions of coldwinter air. The National Park Service is currently try-ing to reinstate the natural temperature profile of thecave.

Nutrient loss from the loss of gray bats apparentlycaused a domino effect in Shelta Cave, in Huntsville,Alabama. Shelta had the most diverse cave communityknown in the southeastern United States, but landdevelopment encroached on the cave in the 1960s andthe townspeople were concerned about youths enter-ing the cave. The cave harbored a large colony of graybats. The National Speleological Society purchased thecave in 1967, and they moved their headquarters to abuilding nearby. They gated the cave in 1968 with astrong, cross-barred gate that had been taken from anold jail. This gate, in hindsight, was inappropriate forbats, which abandoned the cave within two years.Urbanization of the area probably affected the colonytoo. In 1981 a horizontal-bar, bat-friendly door was puton the gate, but no bats returned to the cave. The lossof bat guano to the lake in the cave probably contrib-uted to the decline of cave crayfishes there (Elliott,2000). The gate was replaced with a high fence aroundthe area in the early 2000s, and some bats returned.

WNS is the most severe threat to cave- and mine-hibernating bats to date, killing more than 1 millionbats of nine species from 2006 to 2010 in the easternUnited States and Canada. As the fungal infection,probably originating from Europe, spread from thenortheastern United States into Canada and south andwest as far as Oklahoma, many agencies and land-owners prepared for the worst and wrote responseplans. Thousands of caves were closed or restricted tohuman access to avoid possible spread of the

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ENCYCLOPEDIA OF CAVES

infectious, microscopic spores of Geomyces destructans,the apparent causative agent. Bats spread the spores,but it is not clear how much was spread on unwashedcaving gear and clothing. Strict decontamination rulesare required for anyone to enter many caves now, andan effective treatment is not yet in sight. It is clear thatmore and better cave gates and alarm systems willbe needed for important bat caves, but also moreresearch, bat monitoring, and disease surveillance. It isimpossible and undesirable to gate all caves containingbats, which might number 90,000 or perhaps 100,000caves in the United States. Even noncolonial bats areaffected, such as Perimyotis subflavans, the tri-coloredor eastern pipistrelle bat, and sites remain infectiousfor long periods after bats have died off. Captive hold-ing of bats for study, treatment, or even propagation,may be the last resort for some species that are rapidlydeclining, such as Myotis lucifugus, the little brown bat.It is likely that WNS will spread to the western UnitedStates and even into the highland tropics, whereverbats hibernate in chilly caves and mines.

Many cave bats produce small amounts of guano dur-ing migration and hibernation. If WNS causes a declinein gray bat maternity caves in summer, there could be adecline in nutrient input to some cave systems in thesoutheastern United States. Some conservationists haveproposed replacing lost gray bat guano in caves, butthere are problems in that strategy, as outlined below:

1. Many caves with high biodiversity lack gray bats(Elliott, 2007), so loss of gray bat guano is not ageneral threat to all cave biodiversity.

2. Large-scale guano transfer is an untested idea. Asearch of 25,000 references in the American cavebiology literature found 32 reports on guano, butnone was an experimental transfer of bat guanofrom one cave to another.

3. Large-scale guano transfer from one cave to anothermight introduce infectious Geomyces destructansspores, whereas many are trying to practicecontamination control within caves, as well asdecontamination before and after entering caves.

4. Large-scale guano transfer from a gray bat cavewould disrupt the source cave. Other types, such asfree-tail guano, contain different fauna and flora,and it might be biochemically harmful to therecipient community of guanophiles.

5. The total energy contribution of gray bat guano to acave ecosystem has not been measured well. Manynutrients come from rotting detritus, organics ininfiltrating groundwater, bacteria, fungi, deadpickerel frogs and salamanders, cave crickets, andso on. Most of the carbon flux in two Missouri cavestreams that were studied is from allochthonoussources (Lerch et al., 2000, 2002).

6. Wildlife agencies and researchers do not have themanpower for large-scale guano transfer in ascientifically controlled fashion.

Further discussion of bats may be found below, inthe subsections “Cave Gating Criteria” and “CaveRestoration.”

CAVE PRESERVE DESIGN

Cave conservation encompasses many aspects,which can be applied to developed show caves as wellas to “wild” (unmodified) caves. Show caves, however,have special problems, such as growth of cyanobacter-ia and plants near trail lights, accumulation of “cavelint” and trash, and general disruption of the cave’secology. Some show caves avoid the use of trail lightsbut still have good trails; the visitors are providedwith electric hand lanterns, and viewing native wild-life along the trail is a goal of the tour. Such showcaves usually provide a more educational experiencefor the public.

Good cave management includes rules of access tothe cave. Many publicly owned caves can be left opento the public as long as they do not vandalize or dis-turb cave life.

Besides WNS considerations, some caves require apermit system for entry, based on flooding hazards orother considerations of safety or sensitivity. Usually apermit or restricted access cave would be gated to con-trol access, but appropriate signs are needed to informpeople of the availability of permits (Fig. 1). Certaincaves may be considered closed for recreation, but notfor monitoring and research. Examples include a fewcaves that are especially pristine and rich in multipleresources, or which have overlapping seasons forendangered bats. Heretofore, a few eastern Americancaves harboring gray bats in the summer and Indianabats in the winter were accessible between bat seasonsin May and September, but now few are managed thatway.

Cave preserves have been set aside for the protec-tion of endangered, nonbat species. Too often, how-ever, such preserves surround only the entrance areaand do not include the entire extent of the cave, muchless the recharge area to the cave (often called thewatershed in American usage). It is essential to havegood scientific information about the cave: an accuratemap, a description, inventories of the cave’s resources,and a hydrogeologic assessment. The assessment mayrequire a dye-tracing study in which tracer dyes areput into streams, sinkholes, and other input points.The dyes are recaptured with charcoal traps placed incave streams, springs, or wells. Maps can then be

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drawn that delineate the cave’s water sources, whichmakes it possible to more scientifically manage thelandscape.

Lack of detailed information should not stall conser-vation planning, however. For example, forestersin Missouri try to maintain water quality to ensure apesticide-free food supply for gray bats. They maintaina continuous forest canopy 60 m wide along streams,in the 8 ha around and above gray bat cave entrancesand as travel corridors 60 m wide from gray bat cavesto riparian foraging areas. This canopy provides pro-tection from predators and a substrate for insectproduction.

Buffer zones around small caves in Texas lackingstreams have been as small as one hectare just for theprotection of terrestrial invertebrates. It is importantto maintain native vegetation and drainage patternson the epigeum (surface). Even intermittent cavestreams may have sources beyond a few hectares, sothe preserve would necessarily be larger in such cases.Krejca et al. (2002) recommended a minimum preservesize of 28�40 ha (69 to 99 acres) around a small caveor cave cluster, as well as maintenance and adaptivemanagement against other threats, such as red,

imported fire ants (Solenopsis invicta). If the cave pre-serve is adjacent to undeveloped lands, then occa-sional visits to the cave by raccoons and othernonresident species may continue to provide neces-sary nutrient inputs in the form of droppings. If thepreserve is isolated by developed lands, then it proba-bly should be larger to maintain native flora andfauna. Camel crickets and harvestmen may exit thecave at dusk and forage for carrion and feces in thesurrounding area, but these arthropods may not travelmore than 100 m from the cave entrance. Pesticide useis banned or limited in cave preserves to avoid poi-soning the cave fauna directly or indirectly. Even asmall cave may have to be protected with a strongcave gate to prevent heavy visitation and vandalism,which can alter the cave habitat. Such cave gatesshould be designed to freely allow bats and small ani-mals to pass back and forth. Preserve designs are dis-cussed in various species recovery plans and inguidelines issued by the U.S. Fish and Wildlife Serviceand other agencies.

Buffer zones around large caves may be more diffi-cult to achieve. For example, Tumbling Creek Cave inMissouri has high biodiversity and a recharge area of2331 ha. The cave was under two private properties formany years with extensive forest cover, losing streams,light farming, and cattle production. Even thoughthe cave was managed by the Ozark UndergroundLaboratory, gray bats gradually declined for severalreasons. In the 1990s sedimentation from poor landusage by a neighbor contributed to the decline of acave snail unique to the cave. A drought of severalyears probably contributed to the decline too. Today,more of the cave’s recharge area is under careful landuse, but it remains to be seen if the cave snail willincrease again (USFWS, 2001; Elliott and Aley, 2006;Elliott et al., 2008).

In southeast Alaska’s Tongass National Forest, stud-ies found that some old-growth forest areas had to beprotected on intensely karsted terrain. The limestonewas so pure that little mineral soil had developed, andtrees grew out of a thin moss blanket. When clear-cut,the thin soils washed off into the numerous sinkholes,which fed cave streams, which fed salmon streams. Ina sense, the karst served as three-dimensional streambanks feeding the local streams, and could be consid-ered as stream buffers removed at a distance, and pro-tected under existing laws and forestry standards.Some cave entrances and sinkholes received slash andrunoff from logging and roads, in violation of theFederal Cave Resources Protection Act. Many of theseareas are now protected from road building and tim-ber harvest (Elliott, 1994).

Some states publish “Karst BMP” sheets, providingthe “best management practices” for construction and

FIGURE 1 A 2010 version of a cave sign with information onwhite-nose syndrome.



other ground-disturbing projects on karst. These BMPsshould be applied to prescribed burns and other con-servation projects. Different types of karsts mayrequire different BMPs. The essentials of a karst BMPare summarized below:

1. A karst BMP should generally describe karstgeology, hydrology, and biology, and emphasizethat karst resources are easily damaged bysediments, spills, dumping, and constructionactivities.

2. Identification of sinkholes, recharge areas, sinkingstreams, gaining streams, caves, and springs isneeded to avoid problems. Consult geological,speleological, and state natural heritage surveys.Cave maps are useful for determining the extentof a cave. Dye-tracing studies can delineate therecharge area for a cave, sinkhole, or spring. Somekarst features are hidden under certain soils.

3. Staging and storage areas with fuel and oil shouldbe located away from karst features, and must haveerosion controls. Concrete and wash water isdisposed off-site. Temporary roads should not besteep, and should have runoff controls.

4. Buffer zones of at least 30 m (100 ft) should bemaintained around caves, sinkholes, and springs.Sediment controls are installed upslope of bufferzones. Pesticides and prescribed burning aregenerally banned within buffer zones.

5. Disturbed areas should be revegetated or allowed toregrow after a project. Annual nonnative grassessuch as rye or wheat may be planted in conjunctionwith native species to provide short-term erosioncontrol. Areas subject to erosion may be plantedwith nonnative mixtures for rapid establishmentand erosion control. Follow-up inspections arerequired and continued controls may be necessary.

6. Avoid altering drainage patterns, and properlydispose of debris and trash away from karstfeatures. Temporary erosion controls should beremoved after serving their purpose, but somepermanent controls may be needed.

Cave Gating Criteria

Cave gates are steel structures built to protect caveresources by keeping out human intruders whileallowing air, water, and wildlife to pass freely in andout. Cave gates have locking doors or removable barsso that authorized persons can gain access duringappropriate seasons for necessary work. Poor cavegates can harm wildlife and cave resources, but goodones can improve conditions for bats and other wild-life. Cave gating is not an automatic solution to caveconservation problems and there are many reasons for

not gating a cave. Technical knowledge and experienceare needed to gate a cave; for example, it cannot bedone properly by a general welding contractor withoutproviding specifications, a design, and onsite supervi-sion by an experienced cave gater. Knowledge of caveecology, especially bats, is necessary before a gate isconsidered. Similar techniques are used for gatingabandoned mines, which often harbor bats of greatvalue. Some governmental agencies and cave conserva-tion groups assist cave owners in cave gating, but firsta decision guide must be followed (below).

A few rules of thumb can be followed for cavegates. Natural entrances should not be sealed, butopening a long-sealed cave can also cause problemsfor the cave unless some means of protection isdevised. Gates should not be made of reinforcing bar,or rebar; it is much too weak. Chain link fences areeasily breached, but can be used around sinkholes ifnecessary; stronger “vertical bar fences” are now pre-ferred. Do not construct any raised footings, stonework, or concrete walls on the floor or around a gatebecause they can hinder air exchange and change thetemperature at the bats’ favorite roosts. Gates shouldbe tailored for the wildlife and other resources in thecave. A cave gate is not a substitute for good landmanagement, but it is a last resort.

Limited space does not allow a full discussion hereof the many construction techniques that have beendeveloped for cave gating. Cave gate designs andspecifications by the American Cave ConservationAssociation (ACCA), Bat Conservation International(BCI), Missouri Department of Conservation, andNational Speleological Society (NSS) are available onthe World Wide Web and in publications.

Cave Gate Styles

Depending on the needs of the cave, the type ofentrance, bats and other wildlife, the design could spec-ify a full gate (Fig. 2), half gate or fly-over gate (Fig. 3),window or chute gate (particularly for maternal graybats), cupola or cage gate (Fig. 4), bay window gate,enclosure, fence, or no gate at all. For example, somebat caves that may need a gate for protection are notfeasible to gate for certain physical reasons. Many cavesthat are feasible to gate ought not to be gated becauseother modes of protection may work better.

It is important to rely on an experienced cave-gatingexpert. Leading organizations are ACCA, BCI, U.S.Forest Service, U.S. Fish and Wildlife Service, theMissouri Department of Conservation, NSS, andothers. ACCA’s designs were adopted by BCI andmany government agencies, and have become theindustry standard.

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FIGURE 2 The National Cave Gating Workshop, 2009, built a bat-friendly, full cave gate at Cliff Cave, Missouri, to protect multipleresources, including endangered Indiana bats.

FIGURE 3 A large half gate or fly-over at Great Spirit Cave, Missouri, completed in 2002. The gate weighs 18 metric tons and measures31 m wide by 5 m high. It protects gray bats (Myotis grisescens) in summer, Indiana bats (Myotis sodalis) in winter, and multiple resources inthis Natural Area cave.



The above organizations teach annual, regionalcave-gating workshops to demonstrate the properdecision-making process, design, and constructiontechniques for ecologically sound cave gates (Fig. 2).These gates have resulted in significant protection andincreases of colonies of endangered bats, such as grays,Indianas, and others. Protection of other irreplaceablecave resources is another benefit of properly builtgates. Such workshops may also lead to the formationof regional cave-gating groups from different organiza-tions. The workshop comprises lectures supplementedby building a real cave gate under the direct supervi-sion of cave-gating experts. Each gate is somewhat dif-ferent, and various problems in funding, logistics,design, safety, teamwork, and construction must besolved.

Gates are now made stronger than in the past, but itis important to check and repair them because anycave gate can be breached by determined vandals.Designs have evolved to foil attempts to tunnel undera gate or to destroy the door or lock. Specificationsvary for different gate styles. Gates are usually madeof mild or modified steel “angle iron,” although stain-less and manganal steels may be used in corrosiveenvironments. The latter are more expensive and areunnecessary in most applications. The service life ofmost steel gates may be 30 years.

Cave Gating Decision Guide

Are There Poor Reasons Not to Gate the Cave?

For example,

• Purely aesthetic objections to a gate while the cave’sresources are being degraded anyway.

• It may “start a trend” toward too much gating.• Because a few people consider themselves above the

rules and may threaten the gate.

Score no points for any poor reasons not to gate.

Are There Poor Reasons for Gating the Cave?

For example,

• For fear of liability, which probably is nonexistent.Cave owners are protected by law in some states.

• For administrative convenience (instead of having acomprehensive conservation program).

• To keep wild animals or competing explorers out.

Score no points for any poor reasons to gate.

Are There Good Reasons Not to Gate the Cave?

For example,

• The gate, as designed, will not comply with currentACCA and BCI standards.

• A vigilant owner or manager lives nearby.• Other controls can be used—road gates, signs,

surveillance.• Visitors probably will comply with a good permit

system.• Cave management experts are opposed to the gate.• The cave gaters are inexperienced and overconfident.• No one will commit to checking and maintaining

the gate.• Technical reasons: The entrance is too small for a

proper gate (e.g., half gate for gray bat maternitycolony), or the environment or budget will notallow a good design.

Score one point each against gating if any good rea-sons against gating hold true.

Are There Good Reasons to Gate the Cave?

• The cave is hazardous to casual visitors and noother controls (permits and signs) are adequate.

• Endangered species inhabit the cave and can bebolstered by protection.

FIGURE 4 A cupola or cage gate over a sinkholeentrance, which allows bats to gain altitude and exitlaterally, easier than flying up through a horizontalgrate.

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• The cave is a target for vandals, looters, andtrespassers. A “better clientele” is needed.

• The cave has high value, is threatened, and it canbest be studied and appreciated with a good permitsystem combined with a gate.

Score one point each for gating if any good reasonshold true.

Final Results

Add up the points for and against gating, and deter-mine which seems more important. Other criteria mayhave to be considered.

Security Systems

Electronic technology now allows cave conserva-tionists to deploy alarms and surveillance equipmentin lieu of cave gates, or to supplement gates thatare frequently attacked. Light, vibration and magneticsensors are becoming available that can distinguishhuman intruders from bats and other small animals.

An option for a cave manager would be an audiblealarm versus a silent alarm. The former may frightenoff intruders or anger them, possibly leading to van-dalism of the equipment. A silent alarm would alert anauthority, who could apprehend or warn the intruders.The key question to consider in designing a silent cavealarm system is, “Who will respond, and howquickly?” If law officers or managers cannot respondwithin one hour to apprehend the intruders, then thealarm system probably will not be a deterrent.

There are many options for these security systems, afew of which are outlined below.

Sensors for detecting humans could include attractiveobjects, pressure mats, light detectors, infrared lightbeams, motion detectors, vibration detectors, magneticdetectors, and infrared trail cameras with invisible flash.

The cheapest intrusion detector is an attractive,inexpensive object, such as a coin placed in a knownplace in the cave. If it disappears since the previousvisit, then the manager knows that an unauthorizedperson or a packrat has been there.

Pressure mats were designed for indoor use. Suchmats are switches using no electrical power until theyare triggered by someone stepping on them. They arenot reliable sensors unless they are placed on a flat,hard surface, and then covered with soil. They can belinked together to create a security zone. It may helpto place something just beyond the mats that willattract an intruder and lead him to step on the matunknowingly. A simpler method might be a sign witha momentary switch to the system labeled “Do nottouch this.”

Light detectors are available in custom alarms or asdata loggers, which record the time and date that alight illuminated the detector in the dark zone of thecave. Such data loggers may be used to measure theamount of traffic in well-traveled caves, or to detect ifanyone has trespassed into a closed cave, but the dataare downloaded later and cannot determine anyone’sidentity.

Custom light sensor alarms can alert a manager orlaw officer via radio, telephone, or satellite communi-cation to the Internet. However, it is usually necessaryto install such sensors in the dark zone, leaving theentrance and twilight zone unprotected. They requirecontinuous electrical power, as do motion detectors,which can be accomplished with solar panels and bat-teries or other power sources and cables, which mustbe concealed.

Invisible infrared light beams can be positioned at acertain height so that bats and wildlife are unlikely totrip them, and they can be deployed in the entrance,but false alarms may occur. Arrays of infrared beamsor “beam breakers” are now used to monitor elevatedbat activity during WNS-related activity.

Vibration detectors can be concealed and tuned torespond only to the seismic shaking caused by ahuman walking, or by earthquakes. They are moreeffective when attached to a cave gate, but like all caveelectronics, they must be hardened against the harsh,damp, mineral-rich cave atmosphere, and flooding.

All of the above sensors must be linked to a systemthat conveys information out of the cave, either via acable that must be concealed, or by wireless relays.The system can then trigger an automated telephonecall, radio call, or satellite signal to an authority.

Concealed video and still cameras are routinelyused by law officers to obtain evidence leading to thearrest and conviction of law breakers. The image mustbe clear enough to identify the suspect. They are some-what labor-intensive and vulnerable to attack if theculprit notices the equipment, but they are easilydeployed to new sites as needed.

MANAGEMENTAND EDUCATION

Cave Management

A general goal of land management over a cave isto not alter the landscape much or build infrastructure,such as sewer lines, pipelines, roads, and the like,especially if the cave contains streams and species ofconcern. Paving over the top of a cave cuts off much ofits water supply. Installing septic systems may relegatethe cave to a sewer.



In prescribed burns one should insure that smokedoes not enter caves, especially those occupied byendangered bats. For example, if one burns a hillsideunder certain meteorological conditions, a cold frontmay carry the smoke down the slope and into a cave,especially if it is a cold-air trap. This could be harmfulfor hibernating bats. Conversely, smoke could rise upa hill and into a cave that serves as a summer roost,because it may be a warm-air trap.

Cave Restoration

Many cavers and cave managers favor cave cleanupand restoration projects for multiple reasons. Graffitiremoval may seem to be only an aesthetic pursuit, and itusually does not directly help restore wildlife in the caveunless toxic materials are removed. However, one has toconsider how some caves become targets for vandalism.If a government agency or cave owner allows people tovandalize and litter a cave, then many visitors assumethat it is all right to do so, and they will continue.Inaction is considered condoning the bad behavior.Vandalism sometimes extends to harassment or killingof bats and other wildlife. Trashy caves become traininggrounds for ignorant behavior, places to act up, and thisbehavior spreads to other caves. The same behavior isseen in illegal dumpgrounds, where a few leave somehousehold trash on vacant land. If no one objects, othersthen opportunistically dump there and the problemaccelerates. Signage does not seem to help at that point.

We can involve volunteers in photographing, docu-menting, then carefully removing graffiti. Such a conser-vation project helps to restore public respect for a cave,especially if we publicize the work and explain the effort.An important educational need is filled in this way. Wecan also take the opportunity to educate volunteersabout wildlife during the project, which they appreciate.

Most graffiti that this author has seen is not historicallysignificant, but important signatures and markings areusually left in place or else documented in a photographicfile or database before removal. Certainly aboriginal andother valuable markings and art must be protected.Various rules and laws define the types and ages of mark-ings that must be preserved in place, so it is best to checkwith the appropriate state historical program office aboutsuch requirements. More stringent requirements may bepracticed by conservationists on their own initiative.

An example of restoration is Little Scott Cave inMissouri, managed by the Missouri Department ofConservation (MDC). This cave is near a highway, andit became a target for repeated vandalism, includingextensive and gross graffiti, breakage, spray paintingtwo bats to death, hundreds of beer cans from under-ground parties, and candles from occult ceremonies.

Cavers repeatedly tried to clean up the mess and noti-fied MDC. Finally, MDC gated the cave in April 2000 tostop the cycle. MDC simultaneously instituted an easyprocedure for getting access to the cave by telephoneinterview. MDC awarded grants to two grottoes (cavingclubs) to clean up the cave using low impact techniquesin which no chemicals were used. This work was notedin local newspapers and in Elliott and Beard (2000).

Before restoring a cave to a more natural state, oneshould consider how altered the cave is and definerealistic goals for the restoration project. Is it a showcave with many years of accumulated change and littlehope of complete restoration, or is it a wild cave that isnot so ecologically disturbed? In a show cave nuisancespecies may be present: cyanobacteria near electriclights, exotic species in cave lint along trails, or epi-gean (surface) wildlife that is attracted to artificial foodsources in the cave. The following questions should beasked before planning projects:

1. Do we know what native species should be in thecave?

2. How can we restore the cave to a more normalaesthetic and ecological state without harming thenative species?

3. To what historic or prehistoric period should werestore the cave?

The historic period is an important question in eco-logical restoration for bats, many of which species havedeclined drastically within the past few decades. Somespecies of bat can be protected by bat-friendly gates.Some roosts may return to the “maximum past popula-tion” as measured by ceiling stains. Most colonies donot fully recover. Very large bat colonies (e.g., free-tails)may not tolerate a full gate at all because of the bottleneck, traffic jam, and acoustical confusion it may cause.

It is important not to remove decayed wood andorganic matter from a cave without first checking it forcave life, which may have colonized it over manyyears (Elliott, 2006).

No cave is ever completely restored to its formeraesthetic or ecological state. Proper biological inven-tory and project planning will improve the success ofrestoration efforts.

Prioritizing Caves

Cave protection usually involves crisis management:caves and cave life that are under the greatest threatreceive the most attention. Rarely do we look at cavesover a large region and consider which ones deserveprotection before they become degraded.

Caves can be very different, and comparing and rank-ing them seems difficult. In some states adequate records

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exist to allow cavers, managers, and scientists to evaluateand prioritize caves for protection. Ideally, a cave wouldreceive a numerical score for each of its resources. A com-posite score can then be derived for the whole cave andused for ranking and prioritizing caves or karst regions. Acave could be scored for its length, depth, hydrology, bio-diversity, value as a bat cave, geology, paleontology,archaeology, history, speleothems, aesthetics, recreationalvalue, and the threats against it. There are various waysto score each aspect; for instance, for biodiversity one canconsider the total number of species present, how rare orendemic the cave’s troglobitic species are, the cave’simportance to endangered species, and its overall biodi-versity. Small numerical differences between caves are notimportant, and the rankings are used as a general guide.

Most states have a Natural Heritage Database, usu-ally within a state agency, and many states have a statecave database, usually managed by a nonprofit cavesurvey organization. Increasingly these databases arebeing carefully shared among organizations for thepurpose of protecting significant caves from road andland development and other threats. The locations ofcaves, especially those on private lands, are protectedin each system so as not to draw the attention ofpotential intruders. Coordinates can be truncated tocoarse values for mapping over large areas withoutrevealing cave names or precise locations.

Public Education

Cave conservation includes publications, videos,and educational programs for the public. MDC andother organizations offer workshops on cave ecologyfor biologists and teachers.

It is not necessary for the public to become experi-enced cavers to achieve conservation goals, but it ishelpful to inform the public about all the resources con-nected to caves. Two concepts are important to conveyto the public: (1) caves operate on a much longer timescale than surface landscapes, and are essentially non-renewable resources. (2) Our caves have already lost somuch—when we visit a cave we should give somethingback to it. For example, we can pick up trash, teachothers about cave conservation, or advocate for thecave and the bats to those who have authority over it.Even for those who do not enjoy caves, it is importantto know that bats provide ecosystem services to us inthe form of insect control, and that valuable karstgroundwater resources and caves are highly related.

See Also the Following Articles

Exploration of Caves—GeneralRecreational Caving

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Elliott, W. R. (2000). Conservation of the North American cave andkarst biota. In H. Wilkens, D. C. Culver & W. F. Humphreys(Eds.), Subterranean ecosystems (pp. 665�689). Amsterdam: Elsevier.

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Elliott, W. R., Echols, K., Ashley, D. C., Aley, T., Leary, A., &McKenzie, P. (2008). Waterborne contaminants in TumblingCreek Cave, Missouri. In W.R. Elliott (Ed.), Proceedings of the 18thNational Cave and Karst Management Symposium, October 8�12,2007, St. Louis, Missouri (pp. 107�123). Jefferson City, MO:Missouri Department of Conservation.

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Lerch, R. N., Erickson, J. M., & Wicks, C. M. (2002). Intensive waterquality monitoring in two karst watersheds of Boone County,Missouri. In G. T. Rea (Ed.), Proceedings of the 2001 National Caveand Karst Management Symposium. Tucson, Arizona, October 16�19,2001 (pp. 158�168). Tucson, AZ: USDA-Forest Service, CoronadoNational Forest.

Lerch, R. N., Erickson, J. M., Wicks, C. M., Elliott, W. R., & Schulte, S. W.(2000). Water quality in two karst basins of Boone County, Missouri(Abstract). Journal of Cave and Karst Studies, 62, 187.

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http://www.mdc.mo.gov/conmag/2000/10/cave-restoration

http://www.mdc.mo.gov/conmag/2000/10/cave-restoration

Documents

Encyclopedia of Caves || Protecting Caves and Cave Life