It 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.

A new species of barking deer (Muntiacus spp.) is described from northern Myanmar. Diagnostic DNA character data are presented along with preliminary information on morphology, distribution, and phylogenetic relationships. This discovery contributes significantly to our knowledge of this poorly studied group and highlights the importance of continued field surveys in remote regions. Similar studies have resulted in a significant increase in conservation efforts in other parts of South-east Asia, and argue for additional conservation efforts for this region.

The Belding's yellowthroat (Geothlypis beldingi) is an endemic species of Baja California Sur confined to the edge vegetation of freshwater at several oases. Information on its current status, distribution and habitat selection, and an analysis of the human-related threats that the species faces at 10 oases are given here. Belding's yellowthroats have disappeared from three historical sites, Santiago, Miraflores and El Triunfo, where they were recorded in the early 1900s. Belding's yellowthroats forage mainly in reed grass and cattails in all oases and were never recorded > 50 m outside the edge vegetation of the water. The main threats we detected to their habitat were cutting of reed grass for rural home construction, burning vegetation, opening trails to the water for cattle, overgrazing of reed grass by horses and burros, and using up the water for agricultural and tourism purposes. Although local populations of the species seem to be common, they are vulnerable because the distribution of the species in southern Baja California is patchy. Populations are in general small and isolated, the bird has habitat-specific requirements, and human-related activity is putting pressure on the habitat of this endemic species. A Multidimensional Scaling Analysis showed that southern populations are likely to be more severely affected than northern ones.

The 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.

The major nesting areas for loggerhead turtles in Brazil are estimated to produce about 90% female hatchlings on account of their warm temperatures. In the present study, sand temperatures were monitored at the southern cooler end of the nesting range (Comboios, Espiríto Santo): the temperatures were cool enough to produce a far greater proportion of males than at the major beaches further north. Particular beaches may be thermally suited for the production of a particular sex. Protection of rookeries that appear minor in terms of numbers of turtles nesting could be important for the health of a larger population by insuring that there is an appropriate sex ratio. Temperatures were also monitored in a central guarded hatchery, set back from high seas. The hatchery was thermally similar to zones on the beach where turtles commonly lay, indicating that this conservation practice is unlikely to introduce any large distortions of sex ratio on this beach.

Large 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.

We 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.

Relationships between mean individual fitness and genetic heterozygosity remain controversial because multiple studies over many years have yielded inconsistent results. However, molecular measurements of genetic variation have mostly been based on allozyme markers, which may have substantial limitations due to their relative insensitivity and occasionally also to the effects of natural selection. We investigated variation in the number of tandem dinucleotide repeats at eight polymorphic microsatellite loci in 38 natterjack toad, Bufo calamita, populations that varied in census size, degree of isolation and distance from the distributional range edge. We also measured fitness attributes, notably larval survival and growth rates, under standardized conditions using samples from six of these populations. The results indicated that larval growth rates were positively and strongly correlated with expected heterozygosity (He) across the microsatellite loci. He was in turn highest in large populations with minimal isolation, but low near the biogeographical range edge irrespective of population size. Larvae from the smallest and most isolated natterjack population exhibited particularly low fitness and heterozygosity. Our results suggest that microsatellite loci may provide a valuable new approach in studies of links between fitness and heterozygosity.

Grouse, partridges and pheasants belong to the highly threatened avian order Galliformes. We collected together existing data on the distribution of these species in east Asia (China and Pakistan south and east to the Lesser Sundas in Indonesia and Palawan in the Philippines) from published and unpublished sources. From this we extracted 1068 records of 101 east Asian endemics (plus three other species that have been found in east Asian protected areas) in 369 protected areas. One species was found in 108 protected areas and a further two in 39 and 38 protected areas: six species were not known from any. Of the threatened endemics, 84% were recorded in 10 or fewer protected areas compared with 50% of endemic species that are non-threatened. A near-minimum network designed to include each species in three protected areas wherever possible comprised 49 irreplaceable sites and 33 others. Comparison with other studies should indicate which of these protected areas are also important for other groups of organisms, such as plants and swallowtail butterflies. There is a need for improvement in knowledge of occurrence in protected areas. This should be provided from further collation of existing information and from undertaking targeted surveys. There is also a need to consider which protected areas are suitable for inclusion in a network and how many such areas are required to ensure that each species is adequately represented.

Five 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.

Single locus neutralist models predict that population size bottlenecks will reduce genetic variation and increase inbreeding, thereby reducing evolutionary potential. However, experimental evaluations of the effects of bottlenecks on quantitative genetic variation do not always follow predictions, especially for characters related to reproductive fitness. Populations of Drosophila melanogaster were subjected to population bottlenecks of a single pair for one or three generations, and their ability to tolerate increasing concentrations of NaCl was compared with those of their outbred base populations, and related highly inbred lines. Bottlenecked populations became extinct at significantly lower concentrations of NaCl than their non-bottlenecked base populations. Population bottlenecks should be avoided in managing species of conservation concern.

The 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.

Population viability analysis (PVA) is widely used in conservation biology to compare management strategies and predict probabilities of extinction for endangered species. However, it remains unclear whether the available range of generic PVA programs produce similar predictions when applied to common data sets. A comparative analysis was carried out using six commonly applied PVA packages (GAPPS, INMAT, RAMAS Age, RAMAS Metapop, RAMAS Stage and VORTEX), based on the extensive population data available for the endangered whooping crane, Grus americana. Significant differences were found between the projections of the PVA packages. In particular, the introduction of stochastic variation in breeding structure led to large differences between some packages. Surprisingly, two versions of VORTEX produced very different predictions due to a subtle difference in the way monogamous breeding was modelled. The pattern of similarities and differences among the projections of the packages differ depending on the species examined. In contrast to the predictions of comprehensive (realistic) models, simplified (standardized) models were found to be relatively congruent, which probably reflects similarities in the fundamental biological processes being modelled by the PVA packages. The implications for conservation are clear; caution must be exercised when interpreting the projections of a model built using any one PVA package since, due to seemingly subtle differences in what biological assumptions and threatening processes are included in the models, the predictions among PVA packages (or versions of the same program) are not necessarily concordant.

Faecal oestrogen and progestin analyses were used to assess ovarian activity in non-pregnant scimitar-horned oryx (Oryx dammah) during a 13-month interval. Mean (± SE) luteal phase, interluteal phase and oestrous cycle duration were 18.8 (± 0.5), 5.1 (± 0.2) and 23.8 (± 1.3) days, respectively. All females exhibited a synchronized anovulatory period that ranged from 36–95 days during spring. Short ovarian cycles (10.6 (± 0.8) days) were observed intermittently throughout the year and before the spontaneous resumption of oestrous cyclicity. Periovulatory peaks in oestrogen concentrations were detected for 42.5% (31/73) of ovarian cycles. A parallel analysis of reproductive data from the North American studbook (1985–1994) revealed that captive-held scimitar-horned oryx gave birth throughout the year. Sex ratio at birth was male-biased (54.4%), and 19.1% of all calves failed to survive to 6 months of age (220 out of 1149 births). Only 0.7% of births resulted in twins. Median interbirth interval was 277 days, and 75% of these intervals were less than 332 days. Interbirth interval was extended (P < 0.05) if parturition occurred from January through May. In summary, the scimitar-horned oryx is a seasonally polyoestrous species that experiences a distinct anovulatory period during spring in north-east America.

Infectious 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 response of quantitative traits in translocated populations has not been well explored. Evolutionary shifts in quantitative traits, such as life history characteristics, are of particular interest because of their obvious association with fitness. In a recent survey, Stockwell (1995) examined life history variation of four populations of western mosquitofish (Gambusia affinis) that were derived from a common ancestral population 55–58 years earlier. Three life history traits differed considerably among the four sites and appeared to be correlated with local environmental conditions. To test whether these differences were due to plasticity or rapid evolution, fish from the four sites were maintained under common-garden conditions for two generations. After two generations a genetic basis was inferred for two of the three traits (size at maturity and fat content), but not for the third trait (offspring size). Thus, rapid evolution had occurred for two life history traits in these recently established populations. This case of rapid life history evolution may be due to genetic drift and/or natural selection. These data suggest that translocations may lead to rapid evolutionary responses of targeted taxa. Rapid evolutionary responses are of special concern for ‘refuge’ populations that are maintained as a hedge against extinction.

In 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.

The 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.

In their native Australia, tammar (Macropus eugenii) and parma (M. parma) wallabies are allopatric and differ markedly in habitat use, social structure and degree of reproductive synchrony. They occur sympatrically only on Kawau Is., New Zealand, as a result of introductions last century. Reproductive data collected from wallabies on Kawau Is. in April 1996 show that M. eugenii maintains high reproductive synchrony while M. parma remains asynchronous. Both species show sexual dimorphism and differences in habitat use as seen in Australia. In addition M. parma is more solitary, and is frequently found in closed-canopy woodland, while M. eugenii tends to aggregate in open grassy clearings. Thus the species maintain broad reproductive and biological distinctions, despite enforced sympatry in a novel environment. Highly-resolving genetic (microsatellite) data reveal no evidence for hybridization. This is essential information given the known (M. eugenii) or likely (M. parma) high conservation value of New Zealand stocks. Kawau Is. is the only predator-free site with M. parma, a species whose persistence in Australia is threatened by fox predation. Finally, we use data on mitochondrial cytochrome b sequence divergence amongst several Macropus taxa to demonstrate close agreement with degree of reproductive isolation.

We investigated the distribution of red squirrel (Sciurus vulgaris) populations on the Isle of Wight using Generalized Linear Models (GLMs) and a spatially explicit population dynamics model (SEPM) with the aim of identifying management options for red squirrel conservation. The presence/absence of red squirrels in habitat blocks in the landscape was used as the dependent variable and the size and separation of habitat blocks as independent variables in the GLM analysis. Red squirrel presence within a woodland was significantly related to woodland size and the distance to the nearest wood known to contain squirrels. The SEPM-generated predictions on population viability were closest to the field data when a low dispersal distance of 1 km was used. This suggests that squirrel dispersal on the Isle of Wight is restricted. Our results suggest that some large interconnected woodlands should be maintained if red squirrels are to be conserved for the future.