bluuebunny/crossref_metadata_2025_split huggingface dataset:
A long‐term systematic approach to planning reintroductions: the Persian fallow deer and the Arabian oryx in Israel
Authors: Saltz David 
Published: February 2006

AbstractA long‐term systematic approach to planning the reintroduction of Persian fallow deer (Dama dama mesopotamica) and Arabian oryx (Oryx leucoryx) in Israel is presented. The reintroductions rely on local breeding‐cores that are at their holding capacity of 150 deer and 80 oryx. The approach is based on three elements: (1) maximizing the number of animals that can be withdrawn from a permanent breeding core for the purpose of reintroduction using ‘maximum sustained yield’ (MSY) techniques; (2) determining a priori, using rules‐of‐thumb (such as IUCN Red List Categories), preliminary criteria for project completion; and (3) estimating the time it would take the reintroduced populations to meet the criteria for project completion. I used Monte Carlo Leslie matrix growth models to determine MSY and to project the growth of the reintroduced population. Based on these simulations, the MSY for the fallow deer breeding‐core is 15 adult females in the first year and 12 adult females/year thereafter. The oryx breeding‐core can yield 12 adult females during the first year and 16 adult females every third year thereafter. Project completion was preliminarily set to a wild population of 250 adult deer and 100 adult oryx. The simulations predict that it will take 8–11 years to complete the fallow deer reintroduction and 6–10 years to complete the oryx reintroduction. Post‐release monitoring will help improve the data used in the model and permit re‐assessment of the criteria for project completion.
Impact of poaching on an Asian elephant population in Periyar, southern India: a model of demography and tusk harvest
Authors: Sukumar R. , Ramakrishnan Uma , Santosh J. A. 
Published: February 2006

AbstractIvory poaching has been a serious problem in Asian elephant (Elephas maximus) populations. Reliable records of elephants killed and ivory harvested are generally unavailable. We have used a simulation modelling approach to estimate the numbers of male elephants killed and the quantities of ivory harvested over a 20 year period (1974–94) in the Periyar Reserve of southern India. The age‐structured Leslie matrix projection model was modified for this purpose by considering three segments (female, tusked male and tuskless male), relating fecundity to adult sex ratio and iteratively simulating tusked male mortality rates so as to match the observed elephant population structure at Periyar. Four different scenarios of poaching all gave very similar results. We estimate conservatively that 336–388 tuskers have been poached and 3256–3334 kg of ivory harvested by poachers over the 20 year period. The maximum harvest came from the 10–20 year age class. Trends in various demographic parameters such as population numbers, tusked male to tuskless male ratios and female fecundity are described. The implications of ivory poaching and the extremely skewed sex ratios for the conservation and management of the elephant population at Periyar are discussed.
Behavioural ecology in managed reserves: gender‐based asymmetries in interspecific dominance in African elephants and rhinos
Authors: Berger Joel , Cunningham Carol 
Published: February 2006

AbstractAs large‐bodied mammals become restricted to progressively smaller fragments of former habitat, competitive interactions and interspecies aggression are likely to intensify. Data on the outcomes of 159 encounters between endangered African pachyderms revealed that: (1) female elephants (Loxodonta africana) dominated both sexes of black rhinos (Diceros bicornis); and (2) rhino males but not females displaced elephant bulls. The results of an additional 127 interactions involving pachyderms and 12 additional mammals ranging in size from cheetahs (Acinonyx jubatus) to giraffe (Giraffa camelopardalis) indicates that females of either pachyderm deny immediate access to limited resources. Although the evolution of gender‐specific asymmetries in interspecific dominance has received little formal study, it may best be explained by understanding patterns of parental investment; however, from a conservation perspective, one consequence of size‐related dominance is that with continued containment of elephants and rhinos in managed reserves, the most handicapped species are likely to be the smaller ones.
Phylogeographic uniformity in mitochondrial DNA of the snapping turtle (Chelydra serpentina)
Authors: Walker DeEtte , Moler Paul E. , Buhlmann Kurt A. , Avise John C. 
Published: February 2006

AbstractPrevious studies have revealed considerable genetic variation, geographic localization, and genealogical depth for mitochondrial DNA (mtDNA) haplotypes within each of several species of freshwater turtles in the south‐eastern United States of America. Here we report a notable exception to such phylogeographic patterns. In control‐region sequences of 66 snapping turtles (Chelydra serpentina) collected from 10 south‐eastern states, a single mtDNA haplotype predominated and the two rare variants detected were nearly identical to the common genotype. This pattern of low mtDNA variation and a lack of appreciable geographic population structure is extremely unusual for a widely distributed animal species. For purposes of taxonomy and conservation, these findings suggest the presence of only one ‘evolutionarily significant unit' for C. serpentina in this otherwise phylogeographically rich region of the country. Possible explanations for this phylogeographic pattern in the snapping turtle are considered.
How large must populations be to retain evolutionary potential?
Authors: Franklin I. R. , Frankham R. 
Published: February 2006

AbstractMaintaining genetic variation for future evolutionary change is an important issue for conservation biology. However, there is controversy over the effective population size (Ne) required for endangered species to retain their evolutionary potential, with proposed sizes ranging from 500 to 5000. The highest estimate is based on the assumption that 90% of mutations are deleterious. We review the arguments for an effective size of 5000 and conclude that it assumes effective mutation rates that are too low, and heritabilities that are, in general, very high. We conclude that an Ne of 500–1000 is appropriate at this time.
Population differentiation and conservation of endemic races: the butterfly, Plebejus argus
Authors: Thomas C. D. , Glen S. W. T. , Lewis O. T. , Hill J. K. , Blakeley D. S. 
Published: February 2006

AbstractFive races of the Eurasian silver‐studded blue butterfly, Plebejus argus, are restricted to different habitats in north Wales and north‐west England. One of these races is extinct, and others are threatened. The four extant forms differ in morphology, habitat, host plant choice, performance on different host plant species and species of associated ant. Some of these differences are maintained in captivity, suggesting evolutionary divergence. Different races with different habitat requirements require different practical conservation management to maintain existing populations and metapopulations. Between‐population, or racial, variation is an important consideration in the development of conservation programmes for this and other threatened species. Racial differentiation in P. argus suggests relatively long periods of isolation in particular habitats; the same areas contain other rare species and races. Many countries support the principle of conserving genetic variation within species, but practical methods do not exist for recognizing key areas to prioritize. We suggest that the existence of local races of well‐known taxa may be used to indicate biodiversity hotspots, at a taxonomic level below that of full species. These may represent key locations for the conservation of genetic bio‐diversity.
Identification of evolutionary significant units in the Spanish wild goat, Capra pyrenaica (Mammalia, Artiodactyla)
Authors: Manceau Valérie , Crampe Jean‐Paul , Boursot Pierre , Taberlet Pierre 
Published: February 2006

AbstractThe Pyrenean population of Spanish wild goat (Capra pyrenaica pyrenaica) is nearly extinct. To find the most appropriate source of individuals for supplementing the Pyrenean population, we identified Evolutionary Significant Units (ESUs) among populations of the Capra pyrenaica species. We have examined sequence variability of portions of the mitochondrial DNA (mtDNA) control region and cytochrome b (cyt b) gene. Samples were from seven populations of Spanish wild goat distributed over the species' geographic range. The level of divergence between the Pyrenean and other Spanish haplotypes is almost as high as the divergence between the Alpine (C. ibex ibex) and the Spanish wild goats. In addition, the Pyrenean goat is morphologically distinct from other Spanish wild goats. Therefore the Pyrenean population should be considered as an ESU. For the reinforcement, we suggest either using individuals from the most polymorphic Spanish population, or mixing individuals from diverse Spanish origins, since all the other Spanish populations are equally genetically distant from the Pyrenean population.
Time frames for population viability analysis of species with long generations: an example with Asian elephants
Authors: Armbruster Peter , Fernando Prithiviraj , Lande Russell 
Published: February 2006

AbstractWe extend an earlier population viability analysis (PVA) of the Asian elephant (Elephas maximus) conducted by Sukumar & Santiapillai (1993) in order to examine how conclusions about viability can depend upon the time frame examined. We find that there is an approximately 200 year lag period before extinction events begin to occur in slowly declining populations of E. maximus. Therefore, examining population persistence over a 100 year time frame seriously underestimates the risk of population extinction over a longer, 1000 year period. These results are supported by the use of both a species‐specific model of elephant demography, ELEPHANT, and a generic PVA package, VORTEX.For populations with long generations, a 100 year time period will often not be sufficient to evaluate demographic processes leading to extinction. These results have important implications for how investigators conduct PVAs, and for the listing of endangered species by the World Conservation Union (IUCN).
The question of scale in threat analysis: a case study with Brazilian mammals
Authors: Grelle Carlos E. de V. , Fonseca G. A. B. , Fonseca M. T. , Costa L. P. 
Published: February 2006

AbstractRates of biodiversity loss are clearly associated with a reduction in the extent of original habitat. The most frequently used method to derive such estimates comes from the well‐known species–area relationship. We explored the relationship between habitat loss and area for the Brazilian mammal fauna on a biome level (Atlantic Forest, Cerrado and the Brazilian portion of the Amazon basin), as well as on a smaller regional scale (the Rio Doce Valley of the Atlantic Forest). Habitat loss overestimates the number of threatened species when the entire species pool is considered (endemics and wide‐ranging species). Restricting the analyses to the endemic species, the predicted extinction as a function of habitat loss in the Atlantic Forest and in the Cerrado is found to be greater than the number of taxa actually listed as threatened. This relation is reversed in the Amazon. When considering only the localized species pool for the Rio Doce Valley region of the Atlantic Forest, the function accurately predicts the number of extinctions resulting from habitat loss. We suggest that there is both theoretical and empirical evidence to suggest that threat analysis will generate more accurate estimates of species loss when conducted on a more local scale, particularly for the fauna of non‐insular, continental regions. Furthermore, other phenomena affecting the likelihood of extinction of certain groups of species, such as hunting, need to be taken into account in order to better understand the dynamics of biodiversity loss.
Helping reintroduced houbara bustards avoid predation: effective anti‐predator training and the predictive value of pre‐release behaviour
Authors: Heezik Yolanda van , Seddon Philip J. , Maloney Richard F. 
Published: February 2006

AbstractThe success of captive‐breeding and release programmes is often compromised by predation of released individuals, which are naïve about predators. Pre‐release behavioural preparation of release candidates in the form of anti‐predator training has been attempted infrequently, usually using models of predators, but success was most often measured in terms of improved behavioural responses rather than survival to breeding age after release. Here we report that post‐release survival of captive‐reared houbara bustards (Chlamydotis [undulata] macqueenii) was improved through exposure to a live predator before release: a result with possible applications for a wide range of species currently the focus of reintroduction projects. We also show that rearing houbara with minimal human contact and training with a model of a predator had no effect on post‐release survival. Moreover, neither pre‐release behavioural responses to a model predator nor the degree of tonic immobility were predictors of post‐release survival.
Molecular genetic relationships of the extinct ostrich, Struthio camelus syriacus: consequences for ostrich introductions into Saudi Arabia
Authors: Robinson Terence J. , Matthee Conrad A. 
Published: February 2006

AbstractWe sequenced part of the mitochondrial DNA control region of the extinct Arabian ostrich, Struthio camelus syriacus, to determine its phylogenetic relationship to the surviving subspecies, and to provide genetic information pertinent to the reintroduction of contemporary ostrich into Saudi Arabia. Parsimony, neighbour joining, maximum likelihood and a minimum spanning network all supported a close genetic association between the Arabian S. c. syriacus and the north African S. c. camelus. Furthermore, all our analyses suggest a recent common ancestry for the southern African S. c. australis and the east African S. c. massaicus. The Somali race, S. c. molybdophanes, was phylogenetically the most distinct of the ostrich taxa. Our data are supportive of a management decision to introduce S. c. camelus into areas once occupied by the extinct S. c. syriacus based predominantly on their geographic proximity and phenotypic features. Moreover, the presence of a shared lineage in these taxa indicates that gene flow between the two geographic forms may have been possible in the recent evolutionary past, probably along the Egyptian–Sinai–Israel passageway.
Range collapse of a tropical cervid (Cervus eldi) and the extent of remaining habitat in central Myanmar
Authors: McShea William J. , Leimgruber Peter , Aung Myint , Monfort Steven L. , Wemmer Christen 
Published: February 2006

AbstractThe thamin (Cervus eldi) is an endangered species of deer whose present range is greatly reduced from its original distribution covering the deciduous forests throughout south‐east Asia. We mapped the present distribution of thamin using ground surveys and tied this information to habitat types derived from satellite images in order to detect patterns that might indicate the landscape features which precipitated the decline. We conducted a survey of 24 out of 28 Myanmar townships that were reported to contain thamin in 1992, and evidence of thamin were found in 23 of these townships, predominately in mixed deciduous forests where dipterocarp trees were present. There was no significant correlation between the number of thamin detected and forest remaining in the township, or the size of the human or livestock population. A landcover classification of Landsat Thematic Mapper images indicated 58% of the study area contained deciduous forest, of which 12% was dipterocarp forest. Forest tracts containing thamin were digitized and landscape analyses were conducted on a resampled habitat map that emphasized dry and dipterocarp deciduous forest. Of six landscape variables measured only core area size was a significant predictor for the presence of thamin. None of the unsurveyed indaing forest tracts possessed a core area large enough to support thamin. The pattern of thamin decline matches predictions that peripheral, rather than central, populations are more likely to persist in declining species.
Managing disease threats to wild mammals
Authors: Woodroffe Rosie 
Published: February 2006

AbstractInfectious disease is an emerging threat that conservationists are ill‐equipped to manage. The threat is greatest for small populations, which can be driven to extinction by virulent pathogens; these are usually generalist pathogens that ‘spill over’ from other host species, often domestic animals. Recent attempts at disease control have taken a variety of forms, some directed at threatened hosts themselves, and others involving reservoir hosts. Thus far, few such attempts have demonstrated clear benefits of intervention, often because they were ‘crisis management’ tactics allowing no comparison with untreated controls. Design of future strategies is hampered by a lack of basic information concerning the pathogens that represent serious threats, their epidemiology in multiple‐host systems, and the vaccination or treatment protocols likely to be most effective under field conditions. In general, vaccination and treatment will be most valuable in tiny populations facing very high extinction risks. However, interventions that are poorly planned or under‐funded have the potential to do more harm than good. In larger populations, or over larger areas, intensive management may be inappropriate, unsustainable, or simply impractical. In these circumstances, managing population size, structure or contact between host species could offer promising alternatives to intervention.
The plateau pika (Ochotona curzoniae) is a keystone species for biodiversity on the Tibetan plateau
Authors: Smith Andrew T. , Foggin J. Marc 
Published: February 2006

AbstractIt is necessary to look at the big picture when managing biological resources on the Qinghai—Xizang (Tibetan) plateau. Plateau pikas (Ochotona curzoniae) are poisoned widely across the plateau. Putative reasons for these control measures are that pika populations may reach high densities and correspondingly reduce forage for domestic livestock (yak, sheep, horses), and because they may be responsible for habitat degradation. In contrast, we highlight the important role the plateau pika plays as a keystone species in the Tibetan plateau ecosystem. The plateau pika is a keystone species because it: (i) makes burrows that are the primary homes to a wide variety of small birds and lizards; (ii) creates microhabitat disturbance that results in an increase in plant species richness; (iii) serves as the principal prey for nearly all of the plateau's predator species; (iv) contributes positively to ecosystem‐level dynamics. The plateau pika should be managed in concert with other uses of the land to ensure preservation of China's native biodiversity, as well as long‐term sustainable use of the pastureland by domestic livestock.
Infectious disease and the conservation of free‐ranging large carnivores
Authors: Murray Dennis L. , Kapke Cynthia A. , Evermann James F. , Fuller Todd K. 
Published: February 2006

AbstractLarge carnivores are of vital importance to the stability and integrity of most ecosystems, but recent declines in free‐ranging populations have highlighted the potentially devastating effect of infectious diseases on their conservation. We reviewed the literature on infectious diseases of 34 large (maximum body mass of adults >20 kg) terrestrial carnivore species, 18 of which are considered to be threatened in the wild, and examined reports of antibody prevalence (seroprevalence) and cases of infection, mortality and population decline. Of 52 diseases examined, 44% were viral, 31% bacterial and the remainder were protozoal or fungal. Many infections were endemic in carnivores and/or infected multiple taxonomic families, with the majority probably occurring via inhalation or ingestion. Most disease studies consisted of serological surveys for disease antibodies, and antibody detection tended to be widespread implying that exposure to micro‐organisms was common. Seroprevalence was higher in tropical than temperate areas, and marginally higher for infections known to occur in multiple carnivore groups. Confirmation of active infection via micro‐organism recovery was less common for ursids than other taxonomic groups. Published descriptions of disease‐induced population decline or extinction were rare, and most outbreaks were allegedly the result of direct transmission of rabies or canine distemper virus (CDV) from abundant carnivore species to less‐common large carnivores. We conclude that the threat of disease epidemics in large carnivores may be serious if otherwise lethal infections are endemic in reservoir hosts and transmitted horizontally among taxa. To prevent or mitigate future population declines, research efforts should be aimed at identifying both the diseases of potential importance to large carnivores and the ecological conditions associated with their spread and severity.
Use of genetic data for conservation management: the case of the Arabian oryx
Authors: Marshall T. C. , Sunnucks P. , Spalton J. A. , Greth A. , Pemberton J. M. 
Published: February 2006

AbstractIn this study we investigate some applications of genetic markers in animal conservation, using the Arabian oryx (Oryx leucoryx) as an example. Out of 66 sets of microsatellite primers from other ruminants, 58% were found to amplify microsatellites in Arabian oryx. Polymorphism (50% of loci amplified) and allelic diversity (mean 2.1 alleles/locus amplified) were within the range found in other ruminants. Arabian oryx (n= 343) representing most of the major groups world‐wide were typed at six loci. Low but significant population differentiation was found between most oryx groups, suggesting that management of Arabian oryx has led to substantial genetic mixing between populations. Forty percent of the alleles in one additional Arabian oryx sample from the pre‐extinction population in Oman were not found in any contemporary Arabian oryx, and two out of four contemporary populations were deficient in rare alleles, suggesting that the species has lost some neutral genetic variation. The microsatellite loci were sufficiently polymorphic for identification of an Arabian oryx sample in a forensic context, but were not sufficiently polymorphic for large‐scale parentage inference. We suggest that it is important to evaluate whether genetic markers are likely to have sufficient power to answer particular conservation questions prior to committing conservation resources to genetic typing.