MARCO AND LOUISEMITRANI DEPARTMENTOF DESERT ECOLOGY

Chairperson: Prof. Yael Lubin

Researchers in the Mitrani Department of Desert Ecology use deserts as model ecosystems toadvance the study of ecology in general, and to investigate the ecology of Israel’s deserts inparticular. Our findings can aid the conservation of desert ecosystems and can be applied toenhance prudent and sustainable development of desert regions.

A major departmental project deals with the preservation of biodiversity in arid lands. We areinvestigating environmental heterogeneity (both physical and biological), ecological transformations(natural and man-made), as well as biotic interactions (such as predation, parasitism and resourcecompetition). Changes in the scale of ecological processes and mechanisms involved in creatingand maintaining the diverse patterns of various desert plants and animals are under study.

The range of subjects covered by departmental staff and students includes: physiological ecology,behavioral ecology and life histories, population ecology and genetics, and community andlandscape ecology. Studies in applied ecology, in collaboration with the Jewish National Fundand other organizations, probe the implications of regional development projects, methods ofarresting desertification, and programs initiated to rehabilitate landscapes degraded by humanactivity.

The Mitrani Department facilities include field research sites representing a variety of deserthabitats, animal rooms and outdoor cages, a reference herbarium, areas for garden experimentsin loess and sandy desert soils, and outdoor insect houses. Three research centers are affiliatedwith the Department: The Ramon Science Center (Mitzpe Ramon), the Ha–zeva Research andDevelopment Center (Hazeva, Arava Valley), and the Desertification and Restoration EcologyResearch Center (Sede Boqer Campus), established jointly with the Jewish National Fund.

Phone: 972-8-659-6771 • Fax: 972-8-659-6772 • E-mail: mitrani@bgumail.bgu.ac.il

ACADEMIC STAFFAbramsky, Zvika1

Ayal, YoramKotler, Burt P.Lubin, Yael D.Novoplansky, ArielPinshow, Berry1

Saltz, DavidShachak, Moshe2

ASSOCIATE STAFFBouskila, Amos3

Nathan, Ran3Safriel, Uriel N.4

Yarom, Ilan5

Zaady, Eli2

Ziv, Yaron3

1 Joint appt. with BGU’s Dept. of Life Sciences2 The Desertification and Restoration Ecology Research Center3 Home Department – BGU’s Dept. of Life Sciences4 The Hebrew University of Jerusalem (home university)5 Hazeva Research and Development Center

desertecology 25

View of Nahal Zin

RESEARCH ACTIVITIES

PHYSIOLOGICAL ECOLOGYDesert organisms often have specialized physiological responses not observed in species residingin temperate climates. Departmental researchers investigate the influence of environment on therespiratory physiology, water loss and energy budgets of desert birds and small mammals – andhow these traits influence their life histories.

In 2001, we have completed nearly ten years of work on water balance and energy-substrateuse in free-flying pigeons, which serves as a model for long-distance bird migration. A four-yearstudy of the water, energy and nitrogen balance in desert-dwelling Palestine sunbirds and yellow-vented bulbuls was also completed. The pigeon study produced a complete water-balance ofthese birds while in free-flight, something that has not been achieved for any other species. Animportant and not intuitively obvious finding was that when pigeons are heat stressed duringflight, they cool themselves by increasing cutaneous, rather than respiratory evaporation. Thestudies on sunbirds and bulbuls allowed us to refute the hypothesis that birds with high waterintake, such as those that eat fruit and/or nectar, might resort to increasing urinary ammoniato rid themselves of nitrogen waste, thereby saving water and energy.

With funding from the National Geographic Society, we completed a survey of the bat faunain the Negev highlands.

Various birds regularly undergo extended fasts, with many of them maintaining high-metabolicactivity during long migratory flights. We investigated the effects of fasting on energy substratemetabolism during flight by depriving trained tippler pigeons of food for 2-to-48 h precedingflights of 4 h. Immediately after flight, blood concentrations of uric acid β-hydroxybutyrate andhydroxybutyrate were increased, indicating elevated protein and lipid catabolism during flight.Lighter birds and birds that fasted for longer periods before a flight lost less mass during a 4-hflight than heavier ones and those that fasted for shorter periods. Birds that lost more bodymass during flight had lower blood β-hydroxybutyrate concentrations, suggesting lower in-flightlipid oxidation. Flying pigeons apparently did not compensate for lower lipid catabolism byincreasing protein use. Changes in in-flight protein use were not correlated with either fastduration or preflight body mass. We reasoned that pigeons lost more mass in flight after feedingthan after fasting because recently fed birds utilized more carbohydrates. Thus, pre-flight fastduration is an important determinant of the fuels used in flight.With: L.Z. Gannes, University of Montana, Missoula; K.A. Hatch, Princeton University, New Jersey

We assessed respiratory and cutaneous water loss in trained tippler pigeons both at rest andin free flight. The data indicated that pigeons have more efficient countercurrent heat exchangein their anterior respiratory tract when at rest than in flight, allowing them to recover water thatwould otherwise be lost in their expired breath at rest; the lower the ambient temperature, themore water recovered. When evaporative water loss increases in flight, especially at high ambientair temperature, the major component is cutaneous rather than respiratory. This may result froma reductin in skin water vapor diffusion resistance. Because of the tight restrictions on respiratoryvolume imposed by the bird's requirements for oxygen on the one hand, and maintenance ofblood CO2 levels on the other, the in-flight amount of water potentially lost through respirationis limited.With: G. Michaeli, Ben-Gurion University

EFFECTS OF FASTING ON

IN-FLIGHT FUEL

CATABOLISM OF PIGEONS

PINSHOW

EVAPORATIVE WATER

LOSS FROM FREE-FLYING

PIGEONS

PINSHOW

26desert

ecology

Palestine sunbird (Nectarina osea)feeding on nectar, the subject of

several behavioral and physiologicalstudies at the BIDR

Pigeon resting in its loft

BEHAVIORAL ECOLOGY AND LIFE HISTORIESOrganisms have different ways of coping with marked seasonal changes in resource abundanceand, in particular, the very low abundances typical of many desert ecosystems. They may modifytheir behavior or life history or demographic strategies – namely, by adjusting aspects of growth,reproduction and dispersal. Departmental researchers examine the growth “decisions” of plantsunder different environmental regimes, dispersal mechanisms in plants and animals, and theways that various animals make decisions about foraging, reproduction and development – andthe life history and evolutionary consequences of these decisions.

PLANT DEVELOPMENT AND DISPERSALPlant responses to competition may include costly physiological and morphological changesat the expense of reproduction. It is therefore expected that selection would favor mechanismsthat enable the avoidance of competition among organs of the same plant. We tested whetherplants are capable of self/nonself discrimination, which enables more resources to be allocatedto competitive organs, such as roots, in the presence of nonself competition. Using split-rootexperimentation, we followed the development of double rooted pea plants whose root wasgrown in the presence of a second root belonging to either the same (self) plant or to another(nonself) plant. The plants demonstrated greater root development in the presence and in thedirection of nonself roots. Additional experiments showed that the avoidance of self-competitionis at least partially based on physiological coordination among different organs on the sameplant, rather than on recognition based on chemical signals. This new type of self/nonselfdiscrimination may be common in plants and other organisms where the operation of geneticallybased chemical recognition mechanisms is limited.With: O. Falik

This study focuses on the ways that plants from different ecological backgrounds change theirsize and architecture in response to the availability of limited resources and photoperiodic signals.Trifolium purpureum Loisel (purple clover) plants were collected from Mediterranean (high,relatively predictable resources) and semidesert (low, less predictable resources) populationsin Israel. The plants were grown under high and low water under three photoperiod treatments:“eternal spring” – short nights throughout the growth season; “early spring” – short nights starting70 days before the end of the growth season; and “control” – natural photoperiod conditions.Under the natural photoperiod, the Mediterranean plants developed “optimistically,” producinglarger organs throughout the season. In contrast, semidesert plants developed more “cautiously,”with smaller organs. Under “eternal spring” conditions, plants from both sources flowered andsenesced earlier, as compared to the controls. Under “early spring” conditions, the semidesertplants terminated their vegetative development very soon after the onset of the photoperiodtreatment, while the Mediterranean plants continued their vegetative development similar to thecontrols. We suggest that the effect of environmental signals can be as strong as that of resourceavailability and that their interpretation depends on the plant’s evolutionary history.With: T. Acuña

FORAGING DECISIONSAnimals that cache food act via a personal futures market. Their behavior connects cachingactivities and state-dependent foraging with life expectancy. When a food item can be cachedit has present value if consumed immediately and future value if cached in anticipation of possiblefuture needs. The state of a forager should influence present value, future value and, hence,caching behavior. Future value should improve with the likelihood of future need, the likelihoodthat the cached food item will then be available, and the likelihood that the animal will be aliveto collect it. We studied the way caching animals reveal life expectancy by their balancing ofpresent and future values. Using squirrels, we have shown that animals with low survivorshipexpectations place relatively more value on present consumption than on caching for the futurethan do animals with high expectations of survival. These results demonstrate that squirrels alterforaging and caching behavior according to the future value of their food.With: J.S. Brown, M. van de Merve, University of Illinois, Chicago

27

SELF/NONSELF

DISCRIMINATION IN ROOTS

NOVOPLANSKY

ECOTYPIC DIFFERENCES IN

RESPONSE TO RESOURCE

AVAILABILITY AND

PHOTOPERIOD SIGNALS

NOVOPLANSKY

SQUIRRELS AS FUTURES

TRADERS: CACHING

BEHAVIOR, STATE-

DEPENDENT FORAGING,

AND LIFE EXPECTANCY

KOTLER

desertecology

Foraging behavior provides the link for integrating the interactions of individuals with theirresources, competitors and predators. The study of foraging games sheds light on foragingbehavior, population dynamics, species coexistence and predator-prey interactions. We extendedthe foraging game concept to include many competitors, many predators, two habitats and twomicrohabitats. The added complexity provides added realism and new avenues for competitivecoexistence and predator facilitation. We tested the model by a) quantifying how activity times,apprehension and patch use in gerbils and their predators vary during the night according tothe internal state of the forager, the states of its competitors, moon phase, habitat and microhabitat;b) testing how effectiveness of vigilance, predator lethality, number of predators and marginalvalue of energy affect apprehension; c) quantifying the effect of apprehension on rates of predation;and d) testing for the effect of predator lethality on gerbil population dynamics. To accomplishthese goals, we conducted field and aviary experiments in which we quantified apprehension,foraging activity and patch use of the gerbils and their predators; manipulated the state of targetindividuals; manipulated predator lethality; and quantified rodent population dynamics.With: J.S. Brown, University of Illinois, Chicago

MATING SYSTEMS� PARENTAL CARE AND LIFE HISTORYThe evolution of permanent social living in spiders involved the transition from a typical outbredmating system to regular inbreeding within colonies. Inbreeding is expected to reduce fitnessdue to the accumulation of deleterious alleles, which results in inbreeding depression. Weinvestigated the potential for inbreeding and its fitness consequences in a Negev solitary-livingspecies, Stegodyphus lineatus (Eresidae), which is a member of the same genus as three socialspecies found in Africa and Asia. We found no behavioral avoidance of inbreeding: siblingsmated as readily as nonsibs. Nor was there a reduction in clutch size or hatching rate of theoffspring. Nevertheless, males often dispersed away from their natal neighborhoods to seekmates. First generation inbred and outbred females were similar in body size; inbred males,however, were significantly smaller than outbred males. We found that large males have anadvantage over small males in mating, which suggests that selection favoring large body sizein males may maintain the outbred mating system in this species. In group-living species, wheremany females are available for each male, competition for females is reduced and the matingadvantage of males with large body size is reduced. Thus, social species may not suffer a fitnessloss from inbreeding.With: A.A. Maklakov; T. Bilde-Kofoed, Aarhus University, Denmark; D.R. Smith, University of Kansas, Lawrence

Parental care may have direct and indirect effects on offspring fitness. We investigated the effectsof parental care on the young of the spider Stegodyphus lineatus, a species found in the aridand semi-arid regions of Israel. In this species, the young are released from the single egg sacby the mother and fed by regurgitation for several weeks, after which they kill and consume themother. During the period of maternal care following hatching, the young increase in body massby more than 300%. Scramble competition among the young of the nest may result in the youngdispersing at different body sizes, which may influence their growth and survival after leavingthe maternal nest.With: M. Salomon

POPULATION AND COMMUNITY ECOLOGYDesert communities are unique in two key aspects: the major contributors to the decompositionof plant litter are animal macrodetritivores (e.g., termites, darkling beetles, isopods) and not freemicroorganisms. Macrodetritivores therefore replace herbivores as the main link between plantsand higher trophic levels. We consider the desert community as being composed of four maintrophic links: plants, macrodetritivores, small poikilothermic predators and large endothermicpredators. Along this line of trophic links, large predators control small predators andmacrodetritivores are controlled by their resources. However, in relatively rich habitats whereplant cover is substantial (e.g., wadis), plant cover protects small predators from large ones and

FORAGING GAMES BETWEEN

GERBIL SPECIES AND THEIR

PREDATORS: FREQUENCY-

DEPENDENT BEHAVIOR AND

SPECIES COEXISTENCE

KOTLER, BOUSKILA

THE STRUCTURE OF DESERT

COMMUNITIES

AYAL

PARENTAL CARE AND

MATERNAL EFFECTS IN

SPIDERS

LUBIN

INBREEDING AND THE

EVOLUTION OF SOCIALITY IN

SPIDERS

LUBIN

28desert

ecology

Allenby’s gerbil (Gerbillus andersoniallenbyi) foraging in an experimental

food patch

Stegodyphus lineatus, a subsocialNegev spider, in her nest

the above chain is truncated to only three links, in which small predators are at the top of thechain. Thus in wadis, small predators control macrodetritivores and plant litter is abundant. Wetest our hypotheses in field experiments by manipulating macrodetritivore densities, plant coverand predators.With: M.E. Leibold, University of Chicago, Illinois; Eli Groner, University of Leeds, W Yorkshire, England; E. Elkayam, Ben-Gurion University

CONSERVATION ECOLOGYDesertification spreading in many areas of the world, including the south of Israel, has been welldocumented. This phenomenon, along with man-induced disturbances, can lead to the extinctionof populations and to the reduction of genetic variation in populations that remain. This year,conservation research in the Mitrani Department concentrated on studies of the impact of humanactivities on gazelle populations of gazelles and on the reintroduction by minulating mammalianspecies.

From 1985 to 1993, authorized hunting reduced the gazelle population in the Golan Heightsfrom 5000 to 2500 animals. This action was taken to prevent the outbreak of foot-and-mouthdisease. After hunting ceased, gazelle population continued to decline steadily, with only 500individuals remaining in 2000. We undertook a study to identify the possible causes for thisdecline and to provide management recommendations. We showed that the decline resultedfrom predation of jackals on gazelle fawns. Jackal population density is primarily determined byhuman waste, and it cycles regularly as a function of rabies outbreaks. In 1993, when almost30% of the gazelles were removed by hunting, the jackals were entering a fast growth phaseafter the previous rabies outbreak. This combination of events upset the predator-prey relationship.Because jackals do not depend on gazelles as their single source of food, the gazelle declinedid not bring about an associated decline in jackals. Under these conditions jackals were ableto drive the gazelle population down. Careful handling of human waste is needed to resolve theproblem.

The continued growth of the human population in Israel has brought about increased ecosystempressure by hikers and tourists on previously relatively undisturbed regions. The enhanced levelof contact between man and wildlife can bring about changes in wildlife behavior that mayultimately affect social structure. We evaluated the behavioral responses of gazelles along Israel’ssouthern coastal plain and of ibex in the Eretz Hamakhteshim region to increased humanpresence. In both species, levels of vigilance increase with human disturbance. However thisresponse is stronger in larger animal groups, suggesting that in small groups the maximumpossible levels of vigilance are already in effect. Consequently, the usual advantage of living inlarge groups, which provides enhanced predator detection and avoidance, is lower underdisturbance, and indeed in areas with greater human disturbance, gazelle groups are smaller.With: R. Manor

The high rates of species extinction and loss of biodiversity worldwide has made reintroductionsan attractive technique for restoring damaged ecosystems. In Israel, many species have beenextirpated by uncontrolled hunting and habitat loss during the Ottoman regime. Two of thesespecies, the Persian fallow deer and the Arabian oryx – both listed by the World ConservationUnion (IUCN) as critically endangered – are currently being reintroduced in Israel. We are studyingthe behavior of these species in the wild and their dynamics and habitat preferences, in orderto project future performance. Results have shown that both species have adapted to the wildand exhibit “normal” wildlife behavior patterns and positive growth rates. Computer modelsproject that by the year 2005 there will be nearly 250 Persian fallow deer and 100 Arabian oryxin the wild in Israel.

PERSIAN FALLOW DEER

(DAMA MESOPOTAMICA) AND

ARABIAN ORYX (ORYX

LEUCORYX)

SALTZ

29

STUDYING THE DECLINE OF

MOUNTAIN GAZELLE

(GAZELLA GAZELLA)

POPULATION IN THE GOLAN

HEIGHTS

SALTZ

THE IMPACT OF HUMAN

ACTIVITY ON GAZELLES AND

IBEX IN ISRAEL

SALTZ

desertecology

THE DESERTIFICATION AND RESTORATIONECOLOGY RESEARCH CENTER

Dr. Eli Zaady, Resident Scientist

The DRERC promotes research into the causes of desertification and develops means ofpreventing desertification and of restoring already desertified areas. The Center was establishedin the BIDR at the initiative of the Jewish National Fund (JNF) in order to provide research supportto advance its dryland development projects. The Center’s major activity is the promotion ofrelevant research carried out by graduate students and their supervisors in various Israeliuniversities.

RESEARCH ACTIVITIES

This work presents the scientific background and management principles for establishment ofhuman-made savannas in semiarid regions of the northern Negev desert, Israel. Ecological andhydrological knowledge assist in developing management principles and techniques for increasingbiotic productivity while conserving biodiversity. This includes understanding the relationshipsamong landscape mosaics, resources and organisms. A source-sink relationship among landscapeunits contributes to the diversity and productivity of an area. In desertified locales, the relationshipsare such that water, soil and nutrients leak from the system, decreasing productivity and diversity.We adopted a management approach for retention of resources and harvesting runoff water inorder to increase productivity. The methodology focuses on creating artificial patches relativelyrich in water, as well as on runoff water harvesting and storage.With: Y. Moshe, Jewish National Fund

The northern Negev desert in Israel is a mosaic of two types of plant-community patches. Oneis dominated by vascular plants (shrub patches) and the other by a nonvascular crust community(crust patches), consisting of cyanobacteria, bacteria, algae, mosses and lichens. The crustpatches are sources of soil material and sediment (laden runoff water), while the shrub patchesare the sinks, which function as “islands of fertility” in the desert environment. Accumulation ofresources is often a limiting factor in this ecosystem. We investigated the contribution of high-nutrient, readily decomposable organic residues to the aeolian deposition on the crust patches.During our five years of study, three dominant groups of organic matter were identified: plantmaterial, as well as insect and snail residues (feces). The average accumulation of organic mattershowed significant spatial and temporal attributes. Similar quantities were found on the north-and the south-facing slopes of the watershed, with only a minimum present in the wadi. Asignificant difference of average accumulated organic matter was observed during the five-yearstudy, perhaps because of variations in annual rainfall. The results showed that most of theorganic matter originated in native sources. The highest and most significant amount wasregistered during the spring season, which is the flowering season in the northern Negev. Thismay explain the high quantity of plant material obtained and the great amounts of insect andsnail (feces) residue that were also found during this season. Since the crust patches serve asa source of water and nutrients in this ecosystem, the organic residues that are of high nutrientquality and readily decomposable contribute to the productivity of the shrub patches and therebyof the overall ecosystem.With: Z.Y. Offer, BIDR

ECOLOGICAL APPROACH FOR

AFFORESTATION IN ARID

REGIONS OF THE NORTHERN

NEGEV

ZAADY, SHACHAK

COMPOSITION OF SETTLED

DUST IN THE NORTHERN

NEGEV DESERT

OFFER

30desert

ecology

Livestock grazing is considered a disturbance of biotic and abiotic parameters that is capableof degrading rangelands and inducing desertification. We report on a case in the northern Negevdesert in which grazing was used as a management tool for rehabilitation. The aim of this projectwas to quantify the effects of grazing on a managed ecological system. The diversity andcomposition of the plant community, herbaceous biomass, soil moisture, soil organic matter,habitat structure and quality of the vegetation for grazers (protein content and digestion) weremonitored. These parameters were followed on both the southern and northern slopes becauseof the differences in incident solar radiation, which affect the water regime and vegetation.Monitoring took place both in grazed plots and in plots ungrazed for three years. We found thatgrazing had immediate effects on the plant community and habitat structure: densities of plantspecies decreased (~20%), vegetation was reduced (~50-61%), and exposed soil surfaceincreased (~50%). A significant decrease over time was found in the total protein content ofplants – from 17-19% in beginning of the grazing season to 5-6% at its peak. In the northernslope, digestible material was significantly higher at the peak of the growing season in the grazedplots (63.7%) than in the ungrazed plots (57.4%), but not in the southern slope. When plantdiversity, soil fertility and soil moisture were examined, no correlation was found in relation tograzing. This research shows that livestock grazing can be effective as a management tool byreducing the annual vegetation and increasing the source availability for the trees. It imposedlimited damage to the ecosystem.With: A Perevolotsky, R. Yonatan, Agricultural Research Organization, Volcani Center

Over winter flash floods cause erosion in the basins and adjacent agricultural areas in the semi-arid parts of the Negev. This has led to formation of waterfalls (gullies) that erode streams.Consequently, this has caused the loss of soil nutrients over time. Soil erosion in conjunctionwith human activities has greatly contributed to desertification in this part of the Negev. We setout to examine the effects of soil erosion and agricultural practices in seventeen eroded sitesin the northern Negev desert. Organic carbon increased along a moisture gradient, being lowestin areas receiving 200 mm and highest where rainfall is over 300 mm per year. Nature reserveshad higher organic carbon than cultivated areas. Salinity was highest in the nature reserve sitesand irrigated areas because of accumulation of bases resulting from reduced leaching andcontinuous supplies of heavy metals from brackish water used in the irrigation system, respectively.Water holding capacity was higher in nature reserve soils than in cultivated areas, whereaseroded sites contained bigger soil particles than uneroded ones.With: T. Akuja, Y. Gutterman, BIDR

31

THE EFFECTS OF GRAZING

ON ABIOTIC AND BIOTIC

PARAMETERS IN A SEMI-ARID

ECOSYSTEM

ZAADY, SHACHAK

SOIL EROSION EFFECTS AS

INDICATORS OF

DESERTIFICATION PROCESSES

IN THE NORTHERN NEGEV

ZAADY, AVNI

desertecology

Camels grazing in the Negev

THE RAMON SCIENCE CENTERDr. Boris Krasnov, Head

The Ramon Science Center conducts long-term research on the ecology and geology of theMakhtesh Ramon and its surrounding environment in the central Negev desert. The Center issituated in the town of Mizpe Ramon, about 35-km south of the Jacob Blaustein Institute forDesert Research in Sede Boqer and is affiliated with the Mitrani Department of Desert Ecology.Makhtesh Ramon is a large erosion crater some 40 km long and about 8 km wide, surroundedby 400-meter-high natural walls. Initially established as a geological park because of its remarkablediversity of geological structures and habitats, the crater is now the central constituent of Israel’slargest nature reserve – the Negev Mountains National Park. Makhtesh Ramon is home to awide variety of desert animals and plants, some of which are found nowhere else. Of particularecological interest is the fact that the crater forms a natural boundary between two majorbiogeographic zones, the steppe (Irano-Turanian) and the true (Saharo-Arabian) desert. As such,the crater is an extraordinary natural laboratory for the study of ecological interactions of twofloras and faunas. Our studies cover a variety of topics in structural geology, geomorphology,animal community ecology and ecological parasitology

Phone: 972-8-658-8764 • Fax: 972-8-658-6369 • E-mail: krasnov@bgumail.bgu.ac.il

ACADEMIC STAFFAvni, YoavKrasnov, BorisPlakht, JosefSheinkman, VladimirShenbrot, Georgy

ADJUNCT RESEARCHERSDr. Irina KhokhlovaProf. Emanuel Mazor, Weizmann Institute of Science

RESEARCH ACTIVITIES

GEOLOGY

The geology of the Makhteshim region continues to pose numerous questions concerning theprocesses contributing to the origins of its unique geomorphology. Additionally, Ramon ScienceCenter geologists are investigating processes of erosion that continue to contribute to desertificationof the region.

A dense fault system, active during the Quaternary, runs through the central and southern Negev,west of the Arava Rift. Using the geometry and time relations of the active faults, we definedthe seismic risk within a wide region, covering most of the Makhteshim country; more than 1000joints were identified and classified. The youngest joint systems, which are of Quaternary age(less than 1 million years), were found to be oriented to the N and NE, indicating an ongoingdeformation along the Dead Sea Rift.With: Z. Levi, D. Bahat, Ben-Gurion University

We found that three portions of the geomorphosystem Makhtesh Hazera-Nahal Hazera-NahalZin developed separately. The boundaries between them are expressed as dry waterfalls. Thebroad use of thermoluminescense (TL) dating shows that the Late Pleistocene precursor of theDead Sea, called Lake Lisan, invaded the Nahal Zin valley about 35 Ka and remained there untilapproximately 20 Ka.

ACTIVE FAULTS AND JOINTS

IN THE MAKHTESHIM

COUNTRY: AN INDICATOR OF

RECENT TECTONIC ACTIVITY

AND THE SEISMIC RISK IN

THE REGION

AVNI

EVOLUTIONARY LINKS

BETWEEN MAKHTESH

HAZERA AND THE DEAD SEA

BASIN

SHEINKMAN, PLAKHT

32desert

ecology

By studying the history of recent natural ecosystems, we are able to clarify general trends intheir secular changes, enabling improved environmental reconstructions of earlier events. Thisapproach enabled our elucidation of the dynamics of animal populations of Negev desert in theHolocene and the history of regional vegetation and climate in this epoch. We studied five cavesand rock-shelters. Radiocarbon dating from cave deposits near Mizpe Ramon (Ma’aleh Azmaut)showed that the artificial deposition started here about 5000 years ago. The wide spectrum ofmammal and bird bones, pollen, phitolithes, seeds and shells investigated were found in thekarstic caves in the Nahal Lotz and Neqarot valleys.With: A. Savinetsky, N Kiseleva, B. Khassanov, Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow

ECOLOGYEcological research at the Center focuses on certain key groups of organisms. The distributionand abundance of desert rodents provide insights into behavioral, physiological and ecologicaladaptations to hyperarid habitats. Recently initiated research on the ecology of ectoparasitesshould help us understand the relationships between fleas, which are vectors of several diseases,and their mammalian hosts, as well as the role of environment in mediating these relationships.

ECOLOGY OF ECTOPARASITES AND THEIR RODENT HOSTSWe compared the responses of two fleas, Xenopsylla dipodilli and Parapulex chephrenis,simultaneously exposed to the odors of their respective rodent hosts, Gerbillus dasyurus andAcomys cahirinus. We found that the fleas could discriminate their specific host using the odorcue. Furthermore, females of both flea species produced significantly more eggs when they fedon their specific host than when they fed on other host species.With: I. Khokhlova, BIDR; I. Oguzoglu, Hacettepe University, Ankara, Turkey

The effect of the habitat of host species (rodents) on ectoparasites (fleas) of the Ramon erosioncirque was investigated. We found that one species of flea, Xenopsylla conformis was replacedby a second species, Xenopsylla ramesis, on the rodent hosts, Meriones crassus, living in twodifferent habitats at opposing ends of a steep precipitation gradient. We examined the hypothesisthat air temperature and humidity are important in the structuring of host-ectoparasite relationshipsby altering pre-imaginal flea development. The rates of development of males and females ofthe two species were found to differ with respect to temperature and relative humidity. However,no correlation between development rate and the values of air temperature and relative humidityin the respective habitats was found. Consequently, the paratopic distribution of X. conformisand X. ramesis is caused by factors other than the differential effect of the microclimate parameterson the rate of pre-imaginal development.With: I. Khokhlova, BIDR, N. Burdelova, RSC

Aside from the single report on the cat flea, there is little basic knowledge on flea metabolicrequirements as determined by respiratory gas exchange. Gas exchange in fleas was measuredusing a flow-through respirometry system that monitored CO2 emission. Lowest metabolic rateswere found in the cocoon stages which included prepupa, early stage pupa, late stage pupaand pre-emerged adults. Newly emerged adults and feeding larvae had metabolic rates 2.5 to3 times greater than those of the cocoon stages. Highest rates of gas exchange were found infeeding fleas. The low metabolic requirements of the cocoon stage are thought to contributeto the ability of these stages to survive for longer periods than do free-living larvae or adults.With: I. Khokhlova, BIDR; L. Fielden, Truman State University, Kirksville, MO, USA

ECOSYSTEM DYNAMICS OF

THE CENTRAL NEGEV IN THE

HOLOCENE

PLAKHT

HOST DISCRIMINATION BY

FLEAS USING AN ODOR CUE

KRASNOV, BURDELOVA

DEVELOPMENT RATE OF THE

PRE-IMAGINAL STAGES OF

TWO FLEA SPECIES

(SIPHONAPTERA:PULICIDAE)

AT DIFFERENT AIR

TEMPERATURES AND

RELATIVE HUMIDITIES

KRASNOV

33

RESPIRATORY GAS

EXCHANGE IN THE FLEA

XENOPSYLLA CONFORMIS

(SIPHONAPTERA:PULICIDAE)

KRASNOV

desertecology

PATTERNS OF SPECIES DIVERSITY AND ABUNDANCEThe monitoring of rodent populations began in 1993 on 24 sample grids established in MakhteshRamon and its vicinity. This long-term program aims at assessing how environmental fluctuationsinfluence populations of individual species and the community as a whole. Results of the firstnine years of monitoring were analyzed with regard to the structure and dynamics of the rodentcommunity. Density changes in most rodent species followed fluctuations in the amount ofrainfall. Habitat niche breadth was density-dependent in six species and density-independentin four others. Significant habitat shifts were found in three of ten species. In all pairs composedof species with density-independent variation of habitat breadth and in most pairs where thefirst species had density-independent and the second species had density-dependent variationof habitat breadth, values of habitat overlap were density-independent. However, in most pairscomposed of species with density-dependent variation of habitat breadth, overlap values weresignificantly and positively correlated with density. Composition of spatial guilds was stableproducing five groups in all cases. Only one species (M. crassus) switched its group membershipin a density-dependent manner as a result of density-dependent habitat shifts along thesubstrate/productivity gradient. Within-guild niche overlap increased with density faster thanamong-guild overlap.

ACTIVITY CYCLES AND MICROCLIMATERecent studies on respiratory gas exchange in arthropods have shown that several speciesexhibit a distinctive pattern of external gas exchange, referred to as the discontinuous gasexchange cycle (DGC). This route of water loss can be an important component of the totalwater loss in some species. The study beetle, Pimelia grandis, is common throughout the aridto mesic areas of Israel and Egypt. The form of DGC shown by these beetles is very similar tothat measured in Namib desert tenebrionid beetles. They produced a flutter period, whichconsisted of several discrete bursts of CO2 with little or no CO2 output between these emissions,followed by an unambiguous open period or burst period. Compared to other desert tenebrionidbeetles, P. grandis does not have a long flutter period. There was a significant negative correlationbetween mass-specific metabolic rate and flutter period length. Thus the same amount of CO2

is emitted in a shorter time during the flutter period in order to accommodate the increase inmetabolic demand. This suggests that the flutter period may have some importance in the DGCof P. grandis. The closed period is shorter than expected as it is during this period that no wateris lost through the spiracles. A significant negative correlation between mass specific metabolicrate and closed length was found. Thus to accommodate the increase in metabolic demand,P. grandis reduces the flutter and closed period lengths, but keeps the burst period lengthconstant. P. grandis restricts its activity to night, thereby escaping the extreme saturation of thedesert surface. Moreover by possessing a sub-elytral cavity, the beetle can take advantage ofa form of continuous gas exchange. Continuous gas exchange is an alternative strategy thatmay be advantageous to the beetle. But when water loss becomes too great, the beetle canuse a discontinuous gas-exchange cycle.With: F. Duncan, University of the Witwatersrand, Johannesburg, South Africa

LONG-TERM POPULATION

AND COMMUNITY

DYNAMICS OF RODENTS

IN THE CENTRAL NEGEV

SHENBROT, KRASNOV

STUDY OF THE

DISCONTINUOUS GAS

EXCHANGE CYCLE IN THE

DEHYDRATED TENEBRIONID

BEETLE

KRASNOV

34desert

ecology

RESEARCH INTERESTS

Ph.D. Colorado State University, 1976; ProfessorIncumbent of the Abraham and Bessie Zacks Chair in Desert EcologyCommunity ecology of desert rodents; Applying the theory of density-dependent habitat selectionto measure the magnitude and energetic costs of biotic interactions (competition within andbetween species and predator-prey interactions).Phone: 972-8-646-1342 • Fax: 972-8-647-2890 • E-mail: zvika@bgumail.bgu.ac.il

Ph.D. Hebrew University of Jerusalem, 1998; Researcher Grade CGeology: Morphotectonics; Erosion processes; Palaeogeographic reconstructions.Phone: 972-8-658-8754 • Fax: 972-8-658-6369 • E-mail: avni@bgumail.bgu.ac.il

Ph. D. Hebrew University of Jerusalem, 1978; Senior ResearcherCommunity ecology in relation to primary productivity; Desert community structure; Dynamicsof parasitoid-host interactions from the individual to the population; Dynamics of insect-plantinteractions.Phone: 972-8-659-6774 • Fax: 972-8-659-6772 • E-mail: ayal@bgumail.bgu.ac.il

Ph.D. University of Arizona, 1983; ProfessorCommunity, evolutionary and behavioral ecology; Optimal foraging and habitat use; Trade-offbetween food and safety, implications of information available to foragers; Foraging gamesbetween predators and their prey; Mechanisms of coexistence among desert seed-eating birdsand mammals; Applying foraging theory and mechanisms of species coexistence to conservation.Phone: 972-8-659-6785 • Fax: 972-8-659-6772 • E-mail: kotler@bgumail.bgu.ac.il.

Ph.D. Moscow State University, 1986; Senior ResearcherEcological parasitology; Host-ectoparasite relationships; Population and community ecology ofsmall mammals; Animal behavior (mammals); Community ecology of ground-dwelling arthropods.Phone: 972-8-658-8764 • Fax: 972-8-658-6369 • E-mail: krasnov@bgumail.bgu.ac.il

Ph.D. University of Florida, 1972; ProfessorBehavioral and evolutionary ecology of arachnids, particularly spiders: Mating strategies; Maternalcare of young; Social behavior; Dispersal and population structure; Spider diversity inagroecosystems.Phone: 972-8-659-6782 • Fax: 972-8-659-6772 • E-mail: lubin@bgumail.bgu.ac.il

Ph.D. Hebrew University of Jerusalem, 1990; Senior LecturerEvolutionary ecology, phenotypic plasticity and life history of plants; Plant morphogenesis;Information perception and processing by plants; Genetics of drought-responsive genes; Plantresponse to CO2 fertilization; Ecological implications of wind dispersal of seeds.Phone: 972-8-659-6820 • Fax: 972-8-659-6821 • E-mail: anovopla@bgumail.bgu.ac.il

Ph.D. Ben-Gurion University of the Negev, 1985; Researcher Grade CMolecular biology; Cell biology; Phytochemicals; Signal transduction; Normal and cancer cells;Immunology.Phone: 972-8-658-1641 • Fax: 972-8-658-2068 • E-mail: rivir@bgumail.bgu.ac.il

Ph.D. Duke University, 1975; ProfessorPhysiological ecology; Energy and water exchange in animals; Thermoregulation and osmoregulationin desert animals and flying birds; Avian respiration, thermoregulation and osmoregulation;Physiology of bird migration; Physiological ecology of desert bats.Phone: 972-8-659-6773 • Fax: 972-8-659-6772 • E-mail: pinshow@bgumail.bgu.ac.il

Ph.D. Moscow State University, 1978; Researcher Grade BGeomorphology; Geomorphological and Quaternary mapping; Stratigraphy and palaeogeographyof the Quaternary.Phone: 972-8-658-8764 • Fax: 972-8-658-6369 • E-mail: josefp@bgumail.bgu.ac.il

YORAM AYAL

BURT P. KOTLER

BORIS KRASNOV

35

ZVIKA ABRAMSKY

YOAV AVNI

YAEL D. LUBIN

ARIEL NOVOPLANSKY

RIVKA OFIR

BERRY PINSHOW

JOSEF PLAKHT

desertecology

URIEL N. SAFRIEL Ph.D. Oxford University, 1967; ProfessorAvian ecology; Conservation ecology; Ecology of desertification and global climatic change;Ecological implications of wind dispersal.Phone: 972-8-659-6700 • Fax: 972-8-659-6703 • E-mail: urielsf@bgumail.bgu.ac.il

Ph.D. Colorado State University, 1988; Senior LecturerWildlife management and conservation biology; Wildlife population dynamics; Mountain gazellesand harvesting; Ecology of small populations; Reintroduction of Arabian oryx and Persian fallowdeer; Space-use patterns of wolves in the Golan; Human impact on wildlife; Ecology of ibexpopulations.Phone: 972-8-659-6778 • Fax: 972-8-659-6772 • E-mail: dsaltz@bgumail.bgu.ac.il

Ph.D. Hebrew University of Jerusalem, 1976; Associate ProfessorWatershed ecology of arid lands; Ecology of desertification; Ecological management; Ecologicalsystems; Role of animals in the functioning of arid ecological systems.Phone: 972-8-659-6786 • Fax: 972-8-659-6772 • E-mail: shachak@bgumail.bgu.ac.il

Ph.D. Moscow State University, 1980; Researcher Grade AZoology: Community ecology of desert animals; Protection of endangered and rare species.Phone: 972-8-658-8764 • Fax: 972-8-658-6369 • E-mail: shenbrot@bgumail.bgu.ac.il

Ph.D. Institute of Geography of the Russian Academy of Sciences, 1981; Research AssociateGeography: Quaternary geology and geomorphology.Phone: 972-8-658-8764 • Fax: 972-8-658-6369 • E-mail: sheinkma@bgumail.bgu.ac.il

Ph.D. University of Kansas, 1995; Researcher Grade CEntomology; Biodiversity; Systematics and taxonomy of flies; Biology, ecology and control ofagricultural pests; Desert ecology; Environmental impact of modern settlement on drylands.Phone: 972-8-658-1641 • Fax: 972-8-658-2068 • E-mail: iyarom@bgumail.bgu.ac.il

Ph.D. Hebrew University of Jerusalem, 1992; Researcher Grade CNutrient flows in desert ecosystem; Soil desertification and restoration; Rhizosphere ecology;Soil microbiology and soil microbial ecology; Landscape and microphyte ecology.Phone: 972-8-659-6784 • Fax: 972-8-659-6772 • E-mail: zaady@bgumail.bgu.ac.il

MOSHE SHACHAK

36

DAVID SALTZ

GEORGY SHENBROT

VLADIMIR SHEINKMAN

ILAN YAROM

ELI ZAADY

desertecology

Herd of reintroduced Arabian oryx makes its way east towards Ein Shachak in the Arava.

37

PUBLICATIONS

Avni, Y. Structural and landscape evolution of the Makhteshim country – Interrelations between monoclines, truncation surfaces and the evolutionof the Makhteshim. In: The Makhteshim Country: A Laboratory of Nature; Geological and Ecological Studies in the Desert Region of Israel(Eds. B. Krasnov and E. Mazor), Pensoft, Sofia-Moscow, pp. 33-58 (2001)

Avni, Y., Y. Baetov, Z. Garfunkel and H. Ginat. The Arava Formation – A Pliocene sequence in the Arava Valley, Dead Sea Rift and its western margins,Southern Israel. Israel Journal of Earth Science 51:48-63 (2001)

Avni, Y. and M. Gichua. Erosion as the main cause of ongoing desertification in the Makhteshim country. In: The Makhteshim Country: A Laboratoryof Nature; Geological and Ecological Studies in the Desert Region of Israel (Eds. B. Krasnov and E. Mazor), Pensoft,Sofia-Moscow, pp. 155-169 (2001)

Brown, J.S., B.P. Kotler and A. Bouskila. The ecology of fear and the foraging game between owls and gerbils.Annales Zoologica Fennica 38:71-87 (2001)

Crouch, T. and Y. Lubin. Population stability and extinction in a social spider Stegodyphus mimosarum (Araneae:Eresidae).Biological Journal of the Linnean Society 72:409-417 (2001)

Dall, S.R.X., B.P. Kotler and A. Bouskila. Attention, apprehension, and gerbils searching in patches.Annales Zoologica Fennica 38:15-23. (2001)

Fielden, L., B. Krasnov and I. Khokhlova. Respiratory gas exchange in the flea Xenopsylla conformis (Siphonaptera:Pulicidae).Journal of Medical Entomology 38:735-739 (2001)

Gannes, L.Z., K.A. Hatch and B. Pinshow. Effects of fasting on in-flight fuel catabolism of pigeons.Physiological and Biochemical Zoology 74:1-10 (2001)

Gromov, V., B. Krasnov and G. Shenbrot. Behavioral correlates of spatial distribution in Wagner’s gerbil Gerbillus dasyurus (Rodentia:Gerbillinae).Mammalia 65:111-120 (2001)

Groner, E and Y. Ayal. The interaction between bird predation and plant cover in determining habitat occupancy of darkling beetles.Oikos 93:22-31 (2001)

Horn, H S., R. Nathan and S.R. Kaplan. Long-distance dispersal of tree seeds by wind.Ecological Research 16:877-885 (2001)

Johannesen, J. and Y. Lubin. Evidence for kin structured-group founding and limited juvenile dispersal in the subsocial spiderStegodyphus lineatus. Journal of Arachnology 29:413-422 (2001)

Khokhlova, I., B.Krasnov, G. Shenbrot and A. Degen. Body mass and environment: a study in Negev rodents.Israel Journal of Zoology 47:1-14 (2001)

Kotler, B.P., J.S. Brown, A. Oldfield, J. Thorson and D. Cohen. Foraging substrate and escape substrate: Patch use by three species of gerbils.Ecology 1781-1790 (2001)

Krasnov, B. A monitoring protocol for a nature reserve: A case study for the Ramon Nature Reserve. In: The Makhteshim Country: A Laboratory ofNature; Geological and Ecological Studies in the Desert Region of Israel (Eds. B. Krasnov and E. Mazor),Pensoft, Sofia-Moscow, pp. 309-322 (2001)

Krasnov, B. and I. Khokhlova. The effect of behavioral interactions on the exchange of flea (Siphonaptera) between two rodent species.Journal of Vector Ecology 26:181-190 (2001)

Krasnov, B., I. Khokhlova, N. Burdelova and G. Shenbrot. Flea assemblages on rodents in Makhtesh Ramon: Host-habitat mediation of host-parasite relationships. In: The Makhteshim Country: A Laboratory of Nature; Geological and Ecological Studies in the Desert Region of Israel(Eds. B. Krasnov and E. Mazor), Pensoft, Sofia-Moscow, pp. 251-272 (2001)

Krasnov, B., I. Khokhlova, L. Fielden and N. Burdelova. Development rates of two Xenopsylla flea species in relation to air temperature and humidity.Medical and Veterinary Entomology 15:249-258 (2001)

Krasnov, B., I. Khokhlova, L. Fielden and N. Burdelova. The effect of temperature and humidity on the survival of pre-imaginal stages of two fleaspecies (Siphonaptera:Pulicidae). Journal of Medical Entomology 38:629-637 (2001)

Krasnov, B. and E. Mazor, Eds. The Makhteshim Country: A Laboratory of Nature; Geological and Ecological Studies in the Desert Region of Israel,Pensoft, Sofia-Moscow, pp. 420 (2001)

Krasnov, B., E. Mazor, Y. Avni, J. Plakht and G. Shenbrot. Urban ecology: Mizpe Ramon as an example. In: The Makhteshim Country: A Laboratoryof Nature; Geological and Ecological Studies in the Desert Region of Israel (Eds. B. Krasnov and E. Mazor),Pensoft, Sofia-Moscow, pp. 365-384 (2001)

Krasnov, B. and G. Shenbrot. Tenebrionid beetles of Makhtesh Ramon: Seasonality, diversity and community structure. In: The Makhteshim Country:A Laboratory of Nature; Geological and Ecological Studies in the Desert Region of Israel (Eds. B. Krasnov and E. Mazor), Pensoft, Sofia-Moscow, pp. 187-216 (2001)

Lubin, Y., J.R. Henschel and M.B. Baker. Costs of aggregation: Shadow competition in a sit-and-wait predator. Oikos 95:59-68 (2001)Mazor, E. and B. Krasnov. Epilogue: Vivid research in the Laboratory of Nature. In: The Makhteshim Country: A Laboratory of Nature; Geological

and Ecological Studies in the Desert Region of Israel (Eds. B. Krasnov and E. Mazor), Pensoft, Sofia-Moscow, pp. 403-404 (2001)Mazor E. and B. Krasnov. Makhteshim Country, Ramon Science Center and Nature Laboratory. In: The Makhteshim Country: A Laboratory

of Nature; Geological and Ecological Studies in the Desert Region of Israel (Eds. B. Krasnov and E. Mazor), Pensoft, Sofia-Moscow,pp.1-32 (2001)

desertecology

38

Michaeli, G. and B. Pinshow. Evaporative water loss from free-flying pigeons. Journal of Experimental Biology 204:3803-3814 (2001)Nathan, R. The challenges of studying dispersal. Trends in Ecology and Evolution 16:481-483 (2001)Nathan, R. Dispersal biogeography. In: Encyclopedia of Biodiversity (Ed. S.A. Levin), Academic Press, New York, vol. 2, pp. 127-152 (2001)Nathan, R., U.N. Safriel and I. Noy-Meir. Field validation and sensitivity analysis of a mechanistic model for tree seed dispersal by wind.

Ecology 82:374-388 (2001)Novoplansky, A., contributing author. Intergovernmental Panel on Climate Change (IPCC) Third Assessment Report on Climate Change: Impacts,

Adaptation, and Vulnerability, vol. 2, World Meteorological Organization (WMO), United Nations Environment Programme (UNEP) (2001)Novoplansky, A. and D. Goldberg. Interactions between neighbor environment and drought resistance.

Journal of Arid Environments 47:11-32 (2001)Novoplansky, A. and D. Goldberg. Effects of water pulsing on individual performance and competition hierarchies in plants.

Journal of Vegetation Science 12:199-208 (2001)Ovadia, O., Y. Ziv, Z. Abramsky, B. Pinshow and B.P. Kotler. Harvest rates and foraging strategies in Negev Desert gerbils.

Behavioral Ecology 12:219-226 (2001)Plakht, J. Relief structure and the Quaternary history of the makhteshim. In: The Makhteshim Country: A Laboratory of Nature;

Geological and Ecological Studies in the Desert Region of Israel (Eds. B. Krasnov and E. Mazor), Pensoft, Sofia-Moscow, pp. 59-98 (2001)Prange, H.D., J.L. Shoemaker, Jr., E.A. Westen, D.G. Horstkotte and B. Pinshow. Physiological consequences of oxygen-dependent chloride binding

to hemoglobin. Journal of Physiology 91:33-38 (2001)Saltz, D. Sex ratio variation in ungulates: Adaptation meets environmental perturbation of demography. Oikos 94:377-384 (2001)Saltz, D. Ungulates of Makhtesh Ramon: Dynamics, behavior, and their conservation implications. In: The Makhteshim Country: A Laboratory of

Nature; Geological and Ecological Studies in the Desert Region of Israel (Eds. B. Krasnov and E. Mazor), Pensoft, Sofia-Moscow,pp. 273-298 (2001)

Schneider, J.M., J. Roos, Y. Lubin and J.R. Henschel. Dispersal of Stegodyphus dumicola: They do balloon after all!Journal of Arachnology 29:114-116 (2001)

Sheinkman, V., J. Plakht and E. Mazor. Makhtesh Hazera, the Zin Valley and the Dead Sea basin: Evolutionary links. In: The Makhteshim Country:A Laboratory of Nature; Geological and Ecological Studies in the Desert Region of Israel (Eds. B. Krasnov and E. Mazor), Pensoft, Sofia-Moscow, pp. 97-122 (2001)

Shenbrot, G. and B. Krasnov. Lizards of Makhtesh Ramon: Habitat distribution and spatial organization of communities. In: The Makhteshim Country:A Laboratory of Nature; Geological and Ecological Studies in the Desert Region of Israel (Eds. B. Krasnov and E. Mazor), Pensoft,Sofia-Moscow, pp. 217-234 (2001)

Shenbrot, G. and B. Krasnov. Rodents of Makhtesh Ramon: Habitat distribution and temporal dynamics of the spatial organization of communitiesIn: The Makhteshim Country: A Laboratory of Nature; Geological and Ecological Studies in the Desert Region of Israel (Eds. B. Krasnov andE. Mazor), Pensoft, Sofia-Moscow, pp. 235-250 (2001)

Shenbrot, G. and B. Krasnov. Rodents in desert environment: Is density dynamics really correlated with annual rainfall fluctuations? In:Ecology of Desert Environments: Festschrift for Professor J.L. Cloudsley-Thompson (Ed. I. Prakash), Scientific Publishers,Jodhpur, India, pp. 405-421 (2001)

Shochat E., Z. Abramsky and B. Pinshow. Breeding bird species diversity in the Negev: Effects of scrub fragmentation by planted forests.Journal of Applied Ecology 38:1135-1147 (2001)

Tchabovsky, A., B. Krasnov, I. Khokhlova and G. Shenbrot. The effect of vegetation cover on vigilance and foraging tactics in the fat sand rat,Psammomys obesus. Journal of Ethology 19:107-115 (2001)

Tchabovsky, A., S. Popov and B. Krasnov. Intra- and interspecific variation in vigilance and foraging of two gerbillid rodents, Rhombomysopimus and Psammomys obesus: The effect of social environment. Animal Behaviour 62:965-972 (2001)

Van Tets, I.G., C. Korine, L. Roxburgh and B. Pinshow. Changes in the composition of the urine of yellow-vented bulbuls (Pycnonotus xanthopygos):The effects of temperature, nitrogen and water intake. Physiological and Biochemical Zoology 74:853-857 (2001)

Ward, D., K. Feldman and Y. Avni. The effects of loess erosion on soil nutrients, plant diversity and plant quality in the Negev desert wadis.Journal of Arid Environments 49:1-13 (2001)

Zaady, E., Z.Y. Offer and M. Shachak. The content and contribution of the accumulated aeolian organic matter in a dry ecosystem.Atmospheric Environment 35:769-776 (2001)

Zaady, E., M. Shachak and Y. Moshe. Ecological approach for afforestation in arid regions of the northern Negev Desert, Israel. In: Deforestation,Environment and Sustainable Development: A Comparative Analysis (Ed. D.K. Vajpeyi), Greenwood Publishing Group,Westport, CT, pp. 219-238 (2001)

desertecology

TECHNICAL STAFF

39

MITRANI DEPARTMENT OF DESERT ECOLOGY

Yael Bar-Ilan – Ha–zeva Research and Development CenterSol BrandNadezhda BurdelovaOfer EitanMarc GoldbergDr. Vasiliy Kravchenko – Ha–zeva Research and Development CenterMichal Laniado – Ramon Science CenterMoris Melnikov – Ha–zeva Research and Development CenterIris MusliSonia RosinDror TschoryDanit TellerNatali Zeevi – Ha–zeva Research and Development CenterMarina Zvilikhovsky – Ramon Science Center

Yael KaplanTamar Livne – Ha–zeva Research and Development CenterRinat LukatsOrli Plotkin – Ha–zeva Research and Development CenterMarcia RothAvi Shushan – Ramon Science Center

Robert Dudley – University of Texas, AustinNina Kiseleva – Institute of Ecology and Evolution, MoscowBarry Lovegrove – University of Natal, Pietermaritzburg, South AfricaStanislav Pekar – Masaryk University, Brno, Czech RepublicJerzy Proszynski – Polish Academy of Sciences, WarsawPenny Reynolds – University of Richmond, Richmond, VAThomas Rödl – Max Planck Research Institute for Ornithology, Andechs, GermanyArkady Savinetsky – Institute of Ecology and Evolution, MoscowJon Wright – University of Wales, Bangor Gwynedd, UKAndrei Tchabovsky – Institute of Ecology and Evolution, Moscow

Dr. Trine Bilde-KofoedDr. Carmi KorineDr. Ian Van TetsDr. Kerstin Weigand

Adam Green – Department of Wildlife Ecology, University of Wisconsin, MadisonTodd McWhorter – Department of Ecology and Evolutionary Biology, University of Arizona, TucsonIsik Oguzoglu – Hacceteppe University, Turkey

SECRETARIAL STAFF

VISITING SCIENTISTS

POSTDOCTORAL FELLOWS

VISITING GRADUATE

STUDENTS

desertecology

40

Tania AcunaClara ArizaNoa AvniShirli Bar David (Tel Aviv University)Gil Ben NatanPablo BlinderShlomi BrandwineRami BuchnikShai DanielleAmit DolevAnat DumoshEfrat ElazarOmer FalikZhang FengchunMoses Kirega GichuaAdiv Gal (Hebrew University of Jerusalem)Michal GruntmanDror HablenaHadas HavlenaNimrod Israeli (Hebrew University of

Jerusalem)Anat Levi

Zafrir LeviAlex MaklakovRegev ManorNir MaozShai MarkmanYarden OrenOfer OvadiaAmir Pearlberg (Tel Aviv University)Guy PeerNoam Ra’anan (Hebrew University of

Jerusalem)Dinesh RaoOrnea Reisman-BermanMor SalomonNir SapirPirchia SinaiGil StavHila Tsahor-OhayonSergei VolisGideon WasserbergMichal ZarfatiIdo Zurim

GRADUATE STUDENTS

desertecology

The barn owl (Tyto alba), a major local predator of small ground mammals under study at BIDR