U PDATE IncludingEndangered a Reprint Species of theTechnical latest USFWS Bulletin School of Natural Resources and Environment August 7994 Vol. 7 7 No. 70 THE UNIVERSITY OF MICHIGAN
In this Issue Conservation Biology and Controlling International Status of the African Wild Trade in Endangered Dog, Lycaon pictus Species
Resilience and Resistance: Old Growth Forests and the Relevance for Conservation Puerto Rican Parrot Biology and Management Conservation Biology and Status of the African wild dog, Lycaon pictus by - Joshua R, Ginsberg -
The African wild dog (Lycaon Causes of Decline Loss of habitat and direct persecu- pictus) was once found from Senegal to tion by humans were probably respon- South Africa. Inhabiting a wide range of A number of explanations and hy- sible for initial declines and local extinc- ecosystems, from deserts to the alpine potheses have been invoked to explain tions. Morerecently, other factors which meadows of Mount Kilimanjaro (re- the pan-African decline in Lycaon num- may have led to local or regional de- viewed in Fanshawe et al. 1991 ; Ginsberg bers (Fanshawe et al. 1991). Wild dogs clines in numbers include competition andMacdonald 1990),Lycaon wasprob- occur at low densities relative to other with other carnivores (Frame 1986; ably found in all environments except large predators. For example, while Sinclair, in press); direct conflict with true rainforests. Well over a hundred lions frequently occur at densities of one humans (Childes 1988; Hines 1990; thousand wild dogs, or five times that lion per five square kilometers (Schaller Malcolm 1979); disease (Creel et al., in many, may have lived in Africa at the 1972), wild dog densities average one press; Burrows et al. 1994; Gascoyne et turn of the century. By the 19701s, dog per 70 to 100 square kilometers al. 1993; Alexander et a1.1993; Schaller however, many field biologists began to (Fuller et al. 1992a). In addition, be- 1972; Pienaar 1969); intervention by suspect that the species was in rapid cause wild dogs are highly social ani- scientists (Burrows et al. 1994; Burrows decline. mals that hunt and breed in extended 1992,but see Creel 1992and Macdonald Worried about the decline in wild family packs of up to 50 individuals, et al. 1992); and road kills (Ginsberg dog numbers, two scientists who have each pack encompasses an extremely and Cole, in press). A comparison of studied wild dogs in the Serengeti, John large home range (150 to 2000 square dataon causes of mortality in five differ- Fanshawe and Lory Frame, conducted a kilometers, Fuller et al. 1992). As a ent ecosystems indicated that at any postal survey of researchers and manag- result, wild dogs are probably particu- time in an ecosystem, and through time ers working in Africa in an attempt to larly sensitive to habitat fragmentation in different ecosystems, causes and pat- find out how many wild dogs remained and habitat loss (East 1981). terns of mortality differ (Ginsberg et al., in each range state. Their survey (sum- Wild dogs naturally have high rates in press; Burrows, in press). Studies in marized by Ginsberg and Macdonald of mortality and natality and appear to Botswana and in Kruger National Park 1990) showed that wild dogs have dis- have significant intra- and interpopula- suggest that inter- and intraspecific in- appeared, or have been reduced to relict tion variation in demographic measures teractions are responsible for most adult populations of fewer than 50 individu- (Burrows 1994; Fuller et al. 1992). mortality. In Zimbabwe's Hwange Na- als, in 19 of 34 countries where they Because of their large litter sizes (up to tional Park, mortality associated with once lived. Frame and Fanshawe sug- 16 pups per pack), populations can grow human activity (road kills, snaring)dorni- gested that fewer than 5000 wild dogs rapidly in years of low adult mortality nates. In the Serengeti/Mara over the remain in Africa, and of those individu- and high juvenile survivorship. If, how- past two decades, both interspecificcom- als, fewer than 3000 are found in pro- ever, high adult death rates and low petition (Sinclair in press; Frame 1986; tected areas. A significant decline in juvenile survivorship coincide, popula- Malcolm 1979) and disease appear to numbers has even been evidenced in tions can plummet. Computer modeling have been responsible for a large pro- countries where wild dog populations of Lycaon populations (Ginsberg and portion of adult mortality (Burrows et are relatively large. For example, popu- Mace, in prep) suggests that even wild al. 1994;Malcolm 1979; Schaller 1972). lations in Zimbabwe (Childes 1988) and dog populations as large as 300 indi- While disease may have been re- Namibia (Hines 1990), have halved in a viduals have a distinct probability of sponsible for the local disappearance of decade. In response to these declines, going extinct in under 200 years. How- wild dogs in the Serengeti plains, epi- the wild dog was listed as endangered by ever, if several populations of up to 300 demic disease does not always have the USFWS in 1984. In 1990 the IUCN animals are linked, the probability of catastrophiceffects. In the Selous Game revised its assessment of the status of the extinction drops dramatically. Political Reserve in Tanzania, a closely moni- wild dog from Vulnerable to Endan- initiatives to keep corridors open, such tored outbreak of infectious anthrax had gered, reflecting an increased threat as those found between northern minor effects. In a pack of 42 individu- (Ginsberg and Macdonald 1990). Botswana, western Zimbabwe, eastern als, all adults and yearlings survived and Namibia, and southern Zambia are criti- only four of 24 puppies succumbed to cal, although not necessarily sufficient, the disease (Creel et al., in press). In if this species is to survive. fact, automobiles had a greater effect
1 Endangered Species UPDATE VoL 11 No. 10 1994 than disease on wild dog population both the Selous Reserve in Tanzania Endangewed Species numbers in the Selous Reserve. In (Creel et al., in press) and the Luangwa UPDATE Mikumi National Park, locatedin a small Valley in Zambia (Ginsberg and section of the Reserve, 11 wild dogs Macdonald 1990). A forum for information exchange on were killed by automobiles in one year Rabies was confirmed from analy- endangered species issues alone (Creel and Creel 1994). sis of samples taken from a single wild August 1994 Vol. 11 No. 10 dog carcass in the Serengeti (Gascoyne Effects of Intervention et al. 1993) and two carcasses in the John F. Watson...... Editor Terry Root ...... ,..Faculty Advisor Masai Mara (Richardson et al., in re- Christian Synderman...... Editorial Assistant The need for intensivemanagement view). Individuals in each population Eric he...... Editorial Assistant of fragmented populations is a reality were vaccinated in an attempt to provide Nicole Shutt ...... Subscription Coordinator facing not just wild dogs but many spe- protection against the disease. How- Instructions for Authors: cies of endangered animals. As popula- ever, by 1992 all wild dogs in the study The Endangered Species UPDATE tions become increasingly fragmented, areas in the Serengeti and Masai Mara welcomes articles related to species intensive management, and thus inter- had died or disappeared (Gascoyne et al. protection in a wide range of areas vention, will become more common (see 1993; Burrows et al. 1994). Disappear- including but not limited to: research and management activities and policy analyses papers in Olney et al. 1994). Further- ance of the plains subpopulation of wild for endangered species, theoretical more, many of the data required for dogs in the Serengeti ended a 20 year approaches to species conservation, and conservation planning and management decline in which populations dropped habitat protection. Book reviews, editorial can only be collected with some level of from 77 adults and yearlings in 1970 to comments, and announcements of current events and publications are also welcome. intervention - translocation, disease 26 adults and yearlings in 1977, and then screening and genetic studies, for in- fluctuated between 12 and 31 individu- Readers include a broad range of stance, require anesthesia andlor collec- als from 1976 to 1991 (Burrows, in professionals in both scientific and policy tion of tissue samples. For many spe- press, et al. 1994 ). fields. Articles should be written in an easily understandable style for a knowl- cies -from large, highly mobile ones to Burrows (1992) suggestedthat han- edgeable audience. For further informa- those that are small, cryptic and noctur- dling of the wild dogs to fit radio collars tion, contact the editor. nal -fitting radio transmitters to study and vaccinating the animals with pro- ecology and mortality of animals may jectile darts stressed the dogs, activated Subscription Information: The Endangered Species UPDATE is be the only way in which accurate long- latent disease infections (probably ra- published approximately ten times per year term data can be collected (Kenward bies), and caused the early death of dogs by the School of Natural Resources and 1987). Intervention, however, has po- in these packs. This hypothesis has been Environment at The University of tential costs to survivorship, reproduc- questioned on theoretical grounds by Michigan. Annual rates are $23 for regular subscriptions, and $18 for students and tion, or persistence of apopulation (e.g., Creel (1992), who questioned the evi- senior citizens (add $5 for postage outside Berger and Cunningham 1994; Pietz et dence that handling induced long-term the U.S.). Students please enclose advisor's al. 1993; Cuthill 1991; Hall and stress, and on epidemiologicaland viro- signature on university letterhead. Send Harwood 1990). Inevitably, costs of logical grounds by Macdonald et al. check or money order (payable to The intervention must be balanced against (1992). In a recently published paper, University of Michigan) to: measured benefits. however, data confirm that patterns of Endangered Species UPDATE In studies of wild dogs, interven- wild dog mortality in the Serengeti are School of Natural Resources tion has been demonstrably beneficial. correlated with changes in research prac- and Environment Study of wild dog ecology in all but The University of Michigan tice. The link between correlation and Ann Arbor, MI 48109-1 115 open plains habitats would be impos- causation, however, is uncertain. While (313) 763-3243 sible without the use of radio telemetry changes in mortality are correlated with (Ginsberg et al., in press). Use of telem- changes in research practices, the data Cover: African wild dog (Lycaon pictus) etry has allowed scientists to gain a are also consistent with the explanation Photo by Joshua R. Ginsberg. better understanding of demography, that a disease, either rabies or distemper, The views expressed in the Enhngered feeding ecology, range use, recruitment, could have wiped out the study popula- Species UPDATE are those of the author and causes of mortality. Sample collec- tion even if there had been no handling and may not necessarily reflect those of the tion and long-term monitoring also has U.S. Fish and Wildlife Service or The or vaccination (Burrows et al. 1994). In University of Michigan. shown that disease appears to be rela- the Serengeti during the period in ques- tively common in wild dogs: distemper, tion (1985 to 1992) available data are Production of this issue was made possible parvo-virus, Babesia, and canine insufficient for determining whetherdis- in part by support from the Chevron ehrlichiosis have been isolated or ob- ease induced by handling was respon- Corporation and the US Fish and Wildlife Service Division of Endangered Species served in sera screening in captive and sible for the decline in population num- Region Three. chewon reintroduced animals (Van Heerden bers. 1979,1980, et al. 1989; Alexander et al. Analysis of data from five ecosys- u 1993) . Anthrax has been diagnosed in tems comparing the annual survival of @ printed on recycledpaper
VoL 11 No. 10 1994 Endangered Species UPDATE 2 135 animals that had been handled with the treeless plains of the Serengeti might Genetics, Taxonomy, and the survival of 305 dogs that had not be applicable to conservation and re- Captive Breeding been handled found no difference in search efforts elsewhere, evidence is survival between the two groups accumulating that wild dogs living and Decline in population numbers, re- (Ginsberg et al., in press). In the Kruger hunting in closed habitats (bushland, duction of the species range, and frag- National Park, where over 55% of the woodland) behave differently from those mentation of remaining populations adults and yearlings studied were living in the open plains. should all take their toll on Lycaon ge- handled, population numbers have Comparison of hunting techniques netic variability. Yet effects of habitat doubled since handling began. Disease employed by wild dogs in open and loss and fragmentation on wild dog ge- prevalence was not investigated in all closed environments provides a good netic variability appear to have been ecosystems, but the study in the Selous illustration of these behavioral differ- small. In a collaborative study of ge- coincided with an outbreakof anthrax in ences. Early research on the open plains netic samples collected from wild dogs that population of wilddogs (Creelet al., of the SerengetiMara (Kruukand Turner across eastern and southern Africa, and in press). If an interaction between 1967;Estes and Goddard 1967;Malcolm from wild dogs housed in zoos, Girman handling and latent disease is respon- and Van Lawick 1975) showed that wild et al. (1993) found no significant differ- sible for early mortality of wild dogs in dogs often chase their prey at high speed ences in variability between eastern and the Serengeti, a complex interaction of for long distances, while in the rela- southern African wild dogs, or between factors such as nutrition, disease preva- tively dense bush of Kruger National wild dogs and other large canid species. lence and virulence, and handling must Park, South Africa (Reich 1981), wild Because wild dogs have not been stud- have existed in the Serengeti but not in dogs chased their prey for shorter dis- ied in West Africa, we still know noth- other ecosystems. tances. Furthermore, while wild dogs ing about the genetic/evolutionary his- can approach prey from any direction in tory of Lycaon in this region. Southern Trends in Recent Research open habitats, dogs in denser vegetation and eastern African wild dog popula- will use roads and elephant paths to tions show approximately 1% divergence Until thelate 1980s,our knowledge hunt. Recent studies have yielded simi- in mtDNA sequence and each popula- of African wild dog biology was prima- lar differences in hunting techniques in tion has three distinct mtDNA geno- rily derived from a study conducted from the two habitats. types. Physically, southern wild dogs 1967 to 1978 in the open plains of the Habitat differences also affect the are 30% larger than East African wild Serengeti National Park, Tanzania, and levels of competition and dogs; cranial morphological measures a 1975-1978 study conducted in the kleptoparasitism (the stealing of food by also show a separation between the two Kruger National Park, South Africa other predators) experienced by wild subpopulations. While these data indi- (Reich 1981). Much of the Kruger study dogs in different environments. In open cate that the two populations are distinct and the majority of the early work in the plains of the Serengeti, hyenas were subspecies, recent data (Girman, pers Serengeti focused on the wild dog's present at over 85% of all wild dog kills, com.) show that wild dogs in the Selous complex social organization. From the with parasitism rates a function of the Game Preserve in southern Tanzania point of view of conservation planning, relative ratio of hyena and wild dog have both east and southern African these studies collected insufficient in- group sizes (Fanshawe and FitzGibbon mtDNA genotypes. formation on ecological and demo- 1993). In the Masai Mara, where studies The greatest potential need for wild graphic aspects of the dog's biology. were conducted in a mosaic of grass- dog reintroduction is in East and, if Beginning in the late 1980s, many lands, open woodland, and open habitat exists, West Africa. In these Lycaon research and conservation bushland, hyenas only parasitized 41 % areas, Lycaon populations were either projects were initiated. These research of all kills (Fuller and Kat 1990). In actively exterminated (e.g., Uganda) or efforts have resulted in numerous col- habitats withdenser bush such as Kruger fragmented to the point of disappear- laborative studies of the genetics, be- and Hwange National Parks and Selous ance. Logically, one should attempt havior and ecology of wild dogs in sev- Game Reserve, hyenas parasitize a very reintroduction of wild dogs in large na- eralecosystems (e.g., Fulleret al. 1992a, small percentage (10-16%) of wild dog tional parks of more than 5,000 square b; Girman et al. 1993; Ginsberg et al., in kills and appear to have no effect on kilometers where they have goneextinct press). Of particular interest has been an consumption of prey (Mills and Biggs because of past persecution. Only in expansion of research in woodland and 1993; Creel and Creel 1994; Ginsberg these vast areas of wilderness can a bushland habitats. The Serengeti-Masai unpublished). reintroduced population have any hope Mara ecosystem, in particular the These behavioral and ecological dif- of long-term survival. Potential loca- Serengeti shortgrass plains, is not repre- ferences illustrate the need for wild dog tions for wild dog reintroduction in east- sentative of African ecosystems. Much studies to be conducted in a variety of ern Africa include Virungaand Garamba of Africa, and the majority of African habitats. Information obtained from such National Parks in Zaire, Akagera Na- protected areas, is made up of a mosaic studies will better enable researchers tional Park in Rwanda, and Murchison of closed woodlands, bushlands and and managers to successfully conserve Falls National Park in Uganda. The thickets (White 1983). While studies on and protect the African wild dog. question of what will be used as a source
3 Endangered Species UPDATE VoL 11 No. 10 1994 population for reintroduction attempts decline, national parks and protected Serengeti Hunting Dog Project, 1986-1987, Serengeti Wildlife Research Centre, Seronera. remains. Outside the Selous and areas will offer the only refuge for the Fanshawe, J. H., and C. D. FitzGibbon. 1993. Rungwa-Ruaha Game Reserves in Tan- African wild dog. While a dog may be Factors influencing the hunting success of an zania, few likely sourcepopulations exist man's best friend, the wild dog's future African wild dog pack. Animal Behaviour 45: in eastern Africa. Furthermore, Girman survival will depend on the stewardship 479-490. Frame, L. H., J. R. Malcolm, G. W. Frame, and H. et al.'s 1993 study confirmed, with one of its worst enemy - humans. Van Lawick. 1979. Social organization of exception, studbookdatasuggestingthat African wild dogs (Lycaon pictw ) on the all wild dogs in captivity are of southern Literature Cited SerengetiPlains. ZeitschriftfiirTierpsychology Africa origin. The mesh of need and 50: 225-249. Frame, G. W. 1986. Carnivore competition and availability could not be worse. Alexander, K. A,, P. A. Conrad, I. A. Gardner, C. resource use in the Serengeti ecosystem of The history of reestablishing wild Parish, M. Appel, M. G. Levy, N. Lerche, and Tanzania. Utah State Univ. P. Kat. 1993. Serologic survey for selected Fuller, T. K.,and P. W. Kat. 1990. Movements, dog populations is not encouraging. A microbial pathogens in African wild dogs activity, and prey relationships of African wild reintroduction program in South Africa's (Lycaon pictus) and sympatric domestic dogs dogs (Lycaon pictw) near Aitong, southwest- Umfolozi/Hluhluwe Game Reserve, (Canisfami1iaris)in Maasai-Mara, Kenya. Jour- ern Kenya. African J. Ecology 28: 330-350. nal Of Zoo And Wildlife Medicine 24: 140- sponsored by the Natal Parks Board, has Fuller, T. K., and P. W. Kat. 1993. Hunting used mainly captive-bred animals to at- 144. success of African wild dogs in southwestern Anon. 1994. KrugerNPtranslocateselephant fami- tempt to establish a population in Natal Kenya. J. Mammalogy 74: 464-467. lies for first time, reducing number to be culled. Fuller, T. K., P. W. Kat, J. B. Bulger, A. H. African Wildlife Update 3(3): 5. where wild dogs were pushed to extinc- Maddock, J. R. Gisberg, R. Burrows, J. W. Berger, J. and C. Cunningham. 1994. Active tion by the turn of the century (Skinner McNutt, and M. G. L. Mills. 1992. Population and Smithers 1990). This project has intervention and conservation: Africa's pachy- Dynamics of African wild dogs. In D. R. denproblem. Science 263: 1241-1242 met with limited success in establishing McCullough and H. Barrett, editors, Wildlife Brewer, B. A. and S. Rhodes. 1992. International 2001: Populations. Elsevier Science Publish- a small population of wild dogs. In Studbook for the African wild dog, Lycaon ers, London. contrast, two attempts to reintroduce pictw. Chicago Zoological Society. Gascoyne, S. C., M. K. Laurenson, S. Lelo, and M. Burrows, R. 1992. Rabies in wild dogs. Nature wild dogs to Etosha National Park in Bomer. 1993. Rabies in African wild dogs 359: 277. Namibia failed. The first attempt was (Lycaonpictus) in the Serengeti region, Tanza- Burrows, R. In press. Demographic changes and nia J. Wildlife Diseases 29: 396-402. thwarted before it began when the cap- social consequences in wild dogs 1964-1992. Ginsberg, J. R., and D. W. Macdonald. 1990. in A. R. E. Sinclair and P. Arcese, editor. tive-bred animals contracted a vaccine- Foxes, Jacakals and Wolves: An Action Plan Serengeti 11: research, mnnagement, and con- induced distemper. The second attempt for the Conservation of Canids. IUCN. Gland. servation of an ecosystem. Chicago University Ginsberg, J.R. and M.L. Cole (in press). The failed because the dogs did not success- Press, Chicago. African Wild Dog: Fate Uncertain. New Scien- fully avoid other predators each rein- Burrows, R., H. Hofer, and M. L. East. 1994. - tist. Demography, extinction and intervention in a troduced wild dog was killed by lions Ginsberg, J.R., Alexander, K.A., Creel, S., Kat, small population: the case of the Serengeti wild (L. Sheepers, pers com.). P.W., McNutt, J.W., and Mills, M.G.L. (in dogs. Proceedings of the Royal Society B 256: press). Patterns of Mortality in African Wild Reintroductions of captive-bred 281-292. Dogs (Lycaon pictus): Effects of Handling. animals, particularly social carnivores Childes, S. L. 1988. The status and distribution of Conservation Biology. Lycaon pictus in Zimbabwe. Biol. Conserv. (Yalden 1993), are technically difficult. Ginsberg, J.R. and Mace, G.M. (in prep). Demo- 44: 301-316. While translocation may be simpler than graphic stochasticity, small population size, Creel, S. 1992. Cause of wild dog deaths. Nature and dispersal in the African wild dog: a test of reintroductions (Griffith et al. 1989), 360: 633. models. finding a source population for animals Creel, S., and N. M. Creel. 1994. Ray of Hope for Girman, D. J., R. K. Wayne, P. W. Kat, M. Mills, African Wild Dogs. Miombo 11:l-2. in decline across a subspecies distribu- J. R. Ginsberg, M. Borner, V. Wilson, J. H. Creel, S. and N. M. Creel. In press. Communal tion may be impractical. Yet, because Fanshawe, C. Fitzgibbon, and L. M. Lau. 1993. hunting and pack size in African wild dogs, Molecular-genetic and morphological analyses extinction of individual populations of Lycaon pictus. Animal Behaviour. of the african wilddog(Lycaonpictus). Journal wild dogs is likely, linking populations Creel, S., N. M. Creel, J. A. Matovelo, M. M. A. Of Heredity 84: 450-459. Mtambo, E. K. Batamuzi, and J. E. Cooper. In through wildlife corridors or transloca- Griffith, B. J., M. Scott, J. W. Carpenter, and C. press. The effects of anthrax on endangered tion will be the only strategies that will Reed. 1989. Translocation as a species conser- African wild dogs (Lycaonpictus). Journal of vation tool. Nature 245: 477-480. ensure long-term survival. Zoology. Hines, C. J. H. 1990. Past and present distribution Davies, C. 1993. The home range of the African and status of the Wild Dog, lycaon pictus, in wild dog Lycaon pictus in Hwange National Conclusion Namibia. Madoqua 17: 31-36. Park, Zimbabwe. M. Sc., University of Zimba- Hoff, M., M. Kohn, and S. Baabo. 1992. Excre- bwe, Harare. Unlike many endangered, threat- East, R. (1981a).Arearequirementsandconserva- ment analysis by PCR. Nature 359: 199. Houston, R. A., and R. J. Greenwood. 1993. Ef- ened, and rare species, wild dogs are tion status of large African mammals. Nyala 7(1): 3-20. fects of harness radio transmitters on nesting receiving attention while their popula- captive mallards. Journal of Wildlife Manage- tion numbers are in the thousands, not Estes, R. D., apd J. Goddard. 1967. Prey selection and hunting behaviour of the African wild dog. ment 57: 703-709. hundreds. Nonetheless, in the next 20 J. Wildl. Manage. 31: 52-70. Pietz, P. J., G. L. Krapu, R. J. Greenwood, and J. years wild dogs will probably be re- Fanshawe, J. H., L. H. Frame, and J. R. Ginsberg. T. Lokemoen. 1993. Effects of harness trans- mitters on behavior and reproduction of wild 1991. The wild dog - Africa's vanishing stricted to large areas of relatively un- mallards. Journal of Wildlife Management 57: carnivore. Oryx 25: 137-146. disturbed habitat. As human popula- 696-703. Fanshawe, J. H. 1987. Ongoing report of the tions grow and areas of suitable habitat (Continued on UPDATE page 6)
Vol. 11 No. 10 1994 Endangered Species UPDATE 4 Opinion Resilience and Resistance: Relevance for Conservation by William Burnside Biology and Management
Resilience and resistance, two mea- less than thirty years, seven of twenty- extent to which A changes in response to sures of ecological stability, have wide five bird species were either extinct or a permanent change in B. Variable A applications in conservation biology, yet so rare as to go undetected. may take years to recover after distur- their relevance for conservation manage- bance by B (e.g., Felix et al. 1992). This ment may differ. Resilience measures The Effect of delay increases the probability that B the rate of return of an ecological variable Interconnectedness will act again before A has the opportu- in response to a onetime disturbance. nity to rebound to equilibrium. Indeed, Resistance measures the change in an Species live together as intercon- Fuls and Bosch (1991) describe a situa- ecological variable in response to a per- nected parts of a complex natural ma- tion in which A is unable to achieve its manent disturbance. Natural communi- chinery (Ehrlich 1986). Depending on prior equilibrium state even though B ties are often limited in their ability to degreeofconnectivity, the rate at which disturbs it only occasionally. Actual recover from a single disturbance (e.g., communities recover from disturbance communities are subject to differentlev- Kuss and Hall 1991),and are even further is limited by the recovery rate of their els of disturbance, ranging from none to limited in their ability to recover from less resilient species (Pimm 1991). a constant stream. repeated disturbances. The applicability Golladay et al. (1992) found that streams Several studies have examined the of resilience as a working measure of in clearcut forest areas were more sus- effects of repeated disturbances on com- stability is constrained by the long recov- ceptible to nutrient loading during munities. Folsier (1986) found the veg- ery time of many communities and the storms than streams in intact forest ar- etation in a northern Saharan watershed increasing probability of human-caused eas. Soil and nutrients continued to in a highly unstable state partly due to disturbance. Studying and managing for enter disturbed streams after undis- stress from human-set fires. The fre- long-term ecological change (i.e., resis- turbed streams had recovered. The quent fire disturbances upset the bal- tance) more accurately reflects the reali- resilience of the streams, and thus that ance of a system already stressed from ties faced by many disturbed cornmuni- of the forestlstream complex, was lim- drought. Fuls and Bosch (1991) found ties. ited by the slow recovery rate of the that long-term patchovergrazing stressed forest. vegetation "beyond a threshold of Two Measures of Ecological Areas of interest to conservation drought resilience." Even occasional Stability biologists are likely to be disturbed disturbances can effectively alter a repeatedly. Fuls and Bosch (1991) community's "equilibrium." Resilience measures the rate of re- found that, even after grazing had Pristine systems are subject to oc- turn of an environmental variable follow- stopped altogether, patches of a semi- casional,periodic, or even frequent natu- ing a disturbance (Pimm 1984). An ex- arid grassland that were in poor condi- ral disturbances. However, humans are ample of resilience is the rate at which a tion due to past periodic grazing ex- disturbing areas with increasing fre- deer population regains its former num- panded during drought. The drought quency and intensity, decreasing the bers after aonetime hunting season. Many resilience of the overgrazed patches probability that many communities will natural communitiesrecover slowly from was compromised as aresult of the past recover between perturbations. Further- disturbance. Five years after low-level grazing disturbances. The inability of a more, conservationists are concerned trampling by hikers, the ground flora at population or community to return to with the subset of human-affectedpopu- the Hubbard Brook Experimental Forest equilibrium between successivedistur- lations and areas with the highest prob- in New Hampshire had still not recovered bances recalls another measure of eco- ability of effectively undergoing perma- (Kuss and Hall 1991). Various other logical stability: resistance. nent ecological change. Long recovery communities have similarly low levels of time, together with the increasing prob- resilience (e.g., Felix et al. 1992). Functional Interrelationship ability of disturbance, combine to limit Resistance, another measure of eco- and Probability the relevance of resilience as a working logical stability, gauges the effect of a measure of ecological stability. Resis- permanent change in one variable on Resilience and resistance are func- tance, which measures the response to a another variable, or variables, in a system tionally related. Consider "A" as the permanent change, represents an increas- (Pimm 199 1). An example of resistance variable being disturbed, and "B" as ingly accurate measure of stability. is the response of a deer population to the variable causing the disturbance. permanent hunting pressure. Savidge Resilience, then, is the rate at which A (1987) measured the resistance of Guam's returns to equilibrium following a one- avifauna to an introduced snake. Within time change in B. Resistance is the
5 Endangered Species UPDATE VoL 11 No. 10 1994 Conclusion (continuedfrom UPDATEpage 4) vanHeerden, J. 1980. The transmissionofBabesis Kenward, R. E. 1987. Wildlife radio tagging. canis to the wild dog Lycaonpicfus (Temminck) Academic Press. London. and black-backed jackal Canis mesomelas permanent change is in- Kruuk.. H., . and M. Turner. 1967. Com~arative Shreber. J. S. Afr. Vet. Ass. 51: 119-120. creasingly the rule rather than the excep- notes on predation by lion, leopard, cheetah and vanHeerden, J., N. Bainbridge, R. E. J. Burroughs, tion for natural communities. Unfortu- wild dog in the Serengeti area. Mammalia 31: and N. P. J. Kriek. 1989. Distemper-like dis- 1-27. ease and encephalitozoonosis in wild dogs nately' management is a Macdonald, D W., M. Artois, M Aubert, D L, (Lycaonpictus) (Temick 1820). Onderstepoort triage discipline, whose adherents lack Bisho~,J. R. Ginsberg, A, King, N, ~~k,and K. Vet. Res. 48: 19-21. the resources to save all imperiled spe- B. D. 'Perry. 1992. c;~=of wild dog deaths. White, F. (1983). Vegetation map of Africa., cies and areas. Managers and biologists Nature 360: 633-634. UNESCOIAETFATNNSO, Paris. must therefore concentrate their efforts Maddock, A. H., and M. Mills. 1994. Population Yalden, D. W. 1993. "The problems of reintro- chsrrteristi. of Ahran wild dogs Lycaon ducing carnivores." In N. Dunstone and M. L. I as efficiently as possible. Their con- victus in the eastern transvaal lowveld, South Gorman, editors, Mammals as Predators Sym- I straints necessitate weighing the rela- Africa, as revealed through photographic posia of the Zoological Society of London I records. Biological Conservation 67: 57-62. 69289-306. Oxford University Press, Oxford & tive merit of these different conceptual approaches to ecological stability. While Malcolm, J. R. 1979. Social organisation and UK. communal rearing in African wild dogs. Ph. D. resilience and resistance are important thesis, Harvard University. concepts for research, stability as mea- Malcolm, J. R., and H. van Lawick. 1975. Notes sured by resistance has more immediate on wild dogs (Lycaon pictus ) hunting zebras. relevance for actual conservation and Mammalia 39: 23 1-240. Mills, M. G. L., and Biggs, H. C. (1993). Prey management efforts. apportionment and related ecological relation- ships between large carnivores in Kruger Na- Literature Cited tional Park. In N. Dunstone and M. L. Gorman, editors, Mammals as Predators. Symposia of Ehrlich, P.R. 1986. The Machinery of Nature. the Zoological Society of London 69253-268. Simon and Schuster, New York, N.Y. Oxford University Press, Oxford UK. Felix, N.A., M.K. Raynolds, J.C. Jorgensen, and Olney, P., G. 0. Mace, and A. Feistner. 1994. K.F. Dubois. 1992. Resistance and resilience of Creative Conservation: Interactive Manage- tundra plant communities to disturbance by ment of Wild and Captive Animals. Chapman winter seismic vehicles. Arctic and Alpine Re- and Hall. London, UK. search 2469-77. Pienaar, U. D. V. 1969. Predator-prey relation- Folsier, H. 1986. Forest-savanna dynamics and ships amongst the larger mammals of the Kruger desertification processes in the Gran Sahara. National Park. Koedoe 12: 108-176. Interciencia 11:311-316,357. Reich, A. 1981. TheBehaviourand Ecology ofthe Fuls, E.R. and O.J.H. Bosch. 1991. The influence African Wild Dog (Lycaonpictus )in the Kruger of below-average rainfall on the vegetational National Park. Ph. D. thesis, Yale University. traits of patch-grazed semi-arid grassland. Jour- Richardson, J. D., K. A. Alexander, L. Munson, nal of Arid Environments 21:13-20. and P. W. Kat. In review. An outbreak of rabies Golladay, S.W., J.R. Webster, D.E. Benihid, and among African wilddogs (Lycaonpictus) in the W.I. Swank. 1992. Changes in stream stability Masai Mara, Kenya. Journal of Wildlife Dis- following forest clearing as indicated by storm eases nutrient budgets. Archiv fur Hydrobiologie Schaller, G. B. 1972. The Serengeti Lion: A Study Supplementband 90: 1-33. of Predator-Prey Relations. Univ. of Chicago Kuss, F.R. and C.N. Hall. 91. Ground flora tram- Press. Chicago, IL. pling studies: Five years after closure. Environ- Sinclair, A. R. E.. In press. "Serengeti Past and mental Management 15715-727. Present." In A. R. E. Sinclair and P. Arcese, Pimm, S.L. 1984. The complexity and stability of editors, Serengeti 11: research, management, ecosystems. Nature 307:321-326. and conservation of an ecosystem. Chicago: Pimm, S.L. 1991. The Balance of Nature? Univer- Chicago University Press. sity of Chicago Press, Chicago, IL. Skead. 1980. Historical mammal incidence in the Savidge, J.A. 1987. Extinction of an island forest Cape Provence. Dept. of Nature and Environ- avifauna by an introduced snake. Ecology mental Conservation. Cape Town. f 68:660-668. Skinner, J, D, and R H N Smithers. The Mammals of the Southern African Subregion, Second Edition. Pretoria, South Africa: Univ. of Pretoria, 1990. Stander, Philip E. 1991. Aspects of the ecology and scientific management of large carnivores in sub-Saharan Africa. M. Phil. Thesis, Cam- bridge University, UK. Joshua Ginsberg is a Research Fellow in Ecology William Burnside is a graduate student at the Stanley Price, M. R. 1989. Animal reintroduction: at the Institute of Zoology, London, and is the University of Michigan's School of Natural Re- the Arabian oryx in Oman. Cambridge Univer- Deputy Chairman of the IUCN-SSC Canid Spe- cialist Group. His research interests focus on the sources and Environment. sity Press. Cambridge, UK. van Heerden, J. 1979. The transmission of canine conservation of Africa's large mammals and their ehrlichiosis in the Wild Dog Lycaon pictus habitat. He can be contacted at: (Temminck) and Black-backed Jackal Canis Institute of Zoology mesomelas Schreber. J. S. Afr. Vet. Ass. 50: Regents Park 245-248. London NW 1 4ry, UK
VoL 11 No. 10 1994 Endangered Species UPDATE 6 Bulletin Board
Biodiversity Center Listserver Ecosystem Management Study: call Change of Editor for all nationwide projects The Smithsonian Institute, in coop- After serving as editor of the UP- eration with the University of California The University of Michigan's DATE for the past year, Lynn Gooch at Berkely, is pleased to announce the School of Natural Resources and Envi- has completed her graduate work and creation of a new listserver to discuss ronment is sponsoring an Ecosystem left Ann Arbor. Our loss is The Nature information management for the pro- Management Project which will inven- Conservancy's gain, as Lynn accepted a posed U.S. National Biodiversity Infor- tory ongoing ecosystem management position with TNC's ofice in Portland, mation Center. The listserver, Biodicen- efforts nationwide. The goal of this Oregon. Her dedication and expertise L, may be of interest to those desiring project is to assemble a comprehensive will be missed here at the UPDATE and biodiversity information sources and source of information on ecosystem throughout the School of Natural Re- tools. New subscribers from any sector management efforts, to be used as a tool sources and Environment as well. are welcome. Readers can find a short for academics, natural resource manag- Soon after I took over the position description of the Center concept in the ers, and decision-makers. This 'catalog' of editor, a long time UPDATE reader Smithsonian National Museum of Natu- is designed to aid in the development of remarked to me that "the UPDATE keeps ral History's gopher (nmnhgoph.si.edu) new ecosystem management applica- getting better and better." That com- under Biodiversity Programs. tions and the refinement of existing ones. ment is a tribute to Lynn and all the other The draft mission for the Center is The project is currently identifying ef- editors who have come before me. At to function as a clearinghouse to 1) pro- forts which contain at least one of the the same time it presents me with a vide awareness of available biodiversity following two attributes: efforts which challenge to keep the UPDATE at its data and information; 2) enable access extend land management units beyond present level of quality while seeking to to such data and information; and 3) property or political boundaries to in- improve wherever possible. I look for- facilitate the use and exchange of, and corporate ecological boundaries, or ef- ward to that challenge, and1 hope to hear collaborative discussions about, the in- forts revealing a shift in management from UPDATE readers with sugges- formation in order to meet the needs of priorities away from a single resource or tions or ideas. Please call or write to the public and private customers for conser- species emphasis to consideration of address and phone number given on the vation, sustainable use, education, and ecosystem processes. The project is second page, or send E-mail to scientific inquiry. actively soliciting information on exist-
Non-Profit Organization U.S. POSTAGE PAID Ann Arbor, MI UPDATE Permit No. 144 School of Natural Resources and Environment The University of Michigan Ann Arbor, MI 48109-1115