During the 1990s, populations of two species of griffon vulture, the Indian white-backed Gyps bengalensis and the long-billed Gyps indicus, declined by more than 90% throughout India. These declines are continuing and are due to abnormally high rates of both nesting failure and adult, juvenile and nestling mortality. Affected birds exhibit signs of illness (neck drooping syndrome) for approximately 30 days prior to death. Epidemiological observations are most consistent with an infectious cause of this morbidity and mortality. To investigate the cause of these declines, 28 vulture carcases, including adults and juveniles of both species, were examined in detail. Significant post-mortem findings included visceral gout, enteritis, vasculitis and gliosis. Although we have not yet been able to identify the causative agent of the declines, the results of our pathological studies are most consistent with those for an infectious, probably viral, aetiology. We examine hypotheses for the cause of the declines and, based on our epidemiological and pathological findings, we show infectious disease to be the most tenable of these.

We radio-tracked 24 Myotis daubentonii and 35 Myotis nattereri during the swarming season to determine the catchment area of a swarming site and to study habitat preferences of the bats so that important foraging habitats within the catchment area could be identified. Sixty-one percent of individuals were relocated and 39 day roosts were found for 31 bats. Maximum range from the swarming site was 26.7 km for M. daubentonii and 24.8 km for M. nattereri. Minimum convex polygons depicting the minimum catchment area of the swarming site measured 254 km2 for M. daubentonii and 497 km2 for M. nattereri. Including recoveries of ringed bats increases the area enclosed by the maximum range to at least 4118 km2. Compositional analysis of habitat used in relation to that available suggested selection of mixed agricultural areas by M. nattereri. Broad-leaved woodland was preferred for foraging. Parkland, woodland and open-water habitats were common around roosts of M. daubentonii. Such habitats should be conserved and enhanced to protect these species. Some individuals of both sexes returned to the swarming site of capture, but none visited another swarming site. Bats may be faithful to only one site and may be inflexible should that site be destroyed. Because the catchment area of swarming sites is large, such sites are probably important centres of outbreeding. Protection of these mating sites should be a conservation priority, and key habitats should be protected over a large area around swarming sites.

The First Five Years

In 1998 Animal Conservation was launched to provide a new forum for rapid publication of scientifically rigorous studies of conservation biology. It was hoped that articles would draw from a variety of disciplines, ranging from genetics to population biology to behavioural ecology to palaeobiology. Five years on, it is hard to believe that the editorial that accompanied the first issue felt the need to remind people that conservation biology had indeed come of age as a mainstream biological science. The subject is widely taught at universities, fills about a dozen excellent textbooks, and underpins our understanding of a wide variety of high-profile problems from impacts of climate change to loss of biodiversity and management of endangered species and habitats.

During the twentieth century otter (Lutra lutra) populations in central and western Europe declined and became fragmented because of habitat alterations, chemical pollution and direct persecution. In this study we used microsatellites to describe spatial patterns of genetic diversity and subdivision in otters from eight populations in Europe. Genetic diversity was moderately high within populations (He = 0.45-0.77), and significantly partitioned among locations (FST = 0.17; RST = 0.16; P < 0.001). A Bayesian cluster analysis of multilocus genotypes assigned individuals to seven genetically distinct groups, which were partly concordant with the geographical origin of the samples. An assignment test of the individuals to the populations showed that the Danish and, to a lesser extent, the Spanish populations were unique and distinct, whereas the other populations were partially admixed. Inference of past demographic fluctuations from coalescent analysis suggested that otter populations probably declined several thousand years ago, with the exception of the Irish population for which no such decline could be detected. No genetic evidence for recent bottlenecks was found. The historical decline could stem from post-glacial founding events and recolonization of northern Europe after the last glacial maximum, or from more recent dry stages in the early Holocene in central Europe. On the basis of these results, we recommend that recovery plans should promote the expansion of existing natural populations through improvements of river and wetland habitats.

How well can indicator groups, as sets of species with well-known distributions, represent the distribution of overall biodiversity to select networks of areas for conservation? In the literature, reliable indicator groups of complementarity have proven difficult to find, with some taxon-based indicator groups resulting in no more species represented than when areas are chosen at random. We rigorously test which quantifiable characteristics of species make them better components of indicator groups of complementarity in area networks. We find that even indicator groups comprised of randomly chosen, taxonomically unrelated species perform better than randomly chosen areas, and we demonstrate the improved efficiency of protected-area networks possible when using indicator groups chosen on the basis of species' characteristics.

Conservation programmes increasingly involve the translocation of animals to reinforce failing populations or establish new ones. To help guide translocation programmes of swift foxes (Vulpes velox) or other imperilled species, we aimed to discern factors affecting translocation success among reintroduced swift foxes in Canada. Post-release movements characterized three stages. In the initial acclimation phase, foxes moved erratically and quickly distanced themselves from release sites. During the establishment phase, distances from the release site did not change significantly but daily movements were more wide-ranging than those of concurrently tracked, resident swift foxes. In the final settlement phase, movements of translocated foxes reflected those of resident individuals. Radio-telemetry showed that survival and reproductive success were highest for swift foxes with small dispersal distances, suggesting that measures should be taken to acclimatize animals to release sites. Since females had lower survival rates than males, translocations should also use a greater proportion of females to establish balanced sex ratios in the population. Translocated juveniles dispersed less far but survived and reproduced as well as translocated adults, suggesting that juveniles can be used to establish translocated foxes in small, protected areas, while minimizing demographic effects on source populations. The fact that survival rates and litter sizes of translocated foxes were similar to those of resident animals indicates that translocation can be an effective reintroduction tool for this endangered species, and possibly other foxes.

Successful management of endangered species may be greatly facilitated by the ability to monitor population trends. The Australian northern hairy-nosed wombat (Lasiorhinus krefftii) is one of the world's most endangered mammals, but precise abundance estimation by trapping surveys has proven exceedingly difficult. A mark-recapture study was conducted in the sole remaining L. krefftii population, based on microsatellite identification of individuals and their gender from DNA in remotely collected single hairs. Population size was estimated to be 113 (95% confidence interval of 96 to 150). This suggests an increase in population size over the previous estimate of 65 (95% CI 42-186) in 1993, although the estimates did not differ significantly. There was a significant male bias in the sex ratio (2.25 males:1 female), in agreement with recent trapping surveys. The non-invasive approach used here is vital for estimating population size and trends, and hence it is the most important recent advance in the conservation management of the northern hairy-nosed wombat.

With the increasing human population world-wide, animals and humans are sharing more habitat. In this study, we consider the consequences of this habitat usage overlap on the behaviour patterns and social structure of a threatened species. Specifically, we used focal animal samples to collect data on the Cuban rock iguana, Cyclura nubila, in six field sites. Three of these sites are subject to considerable anthropogenic habitat usage, whereas three are in relatively low anthropogenic usage areas. Individuals in high anthropogenic usage sites were more closely assembled, with more males and females sharing a smaller amount of space. These animals exhibited even more aggressive behaviour and social interactions than expected when taking into account the larger number of possible interactants. High anthropogenic usage sites also had more male–male interactions and fewer males interacting with females. We suggest that social and mating system changes have occurred. Ramifications of these recent changes in the behavioural repertoires on the long-term survival of the species are discussed.

To investigate how anthropogenic activity might affect large carnivores, we studied the behaviour of spotted hyenas (Crocuta crocuta) during two time periods. From 1996 to 1998, we documented the ecological correlates of space utilization patterns exhibited by adult female hyenas defending a territory at the edge of a wildlife reserve in Kenya. Hyenas preferred areas near dense vegetation but appeared to avoid areas containing the greatest abundance of prey, perhaps because these were also the areas of most intensive livestock grazing. We then compared hyena behaviour observed in 1996-98 with that observed several years earlier and found many differences. Female hyenas in 1996-98 were found farther from dens, but closer to dense vegetation and to the edges of their territory, than in 1988-90. Recent females also had larger home ranges, travelled farther between consecutive sightings, and were more nocturnal than in 1988-90. Finally, hyenas occurred in smaller groups in 1996-98 than in 1988-90. We also found several changes in hyena demography between periods. We next attempted to explain differences observed between time periods by testing predictions of hypotheses invoking prey abundance, climate, interactions with lions, tourism and livestock grazing. Our data were consistent with the hypothesis that increased reliance on the reserve for livestock grazing was responsible for observed changes. That behavioural changes were not associated with decreased hyena population density suggests the behavioural plasticity typical of this species may protect it from extinction.

Rare bouts of extreme environmental perturbations (catastrophes) have been predicted to have a major influence on the probability of extinction. Yet very little information is available on the frequency and severity of catastrophes. Improving the available information concerning catastrophe parameters would allow for an evaluation of their effect and a start towards understanding their causes. We used the Global Population Dynamics Database to determine the frequency and severity of die-offs in 88 species of vertebrates. We define a catastrophe as any 1-year decrease in population size of 50% or greater. The data yielded three findings. (1) The frequency of severe die-offs in vertebrate populations is strongly related to the generation length of the organism. (2) The probability of a severe die-off for a particular population is approximately 14% per generation. (3) The frequency of die-off severity can be modelled as a modified power function with the frequency of die-offs decreasing with increasing magnitude of effect. The distribution is not consistent with catastrophes stemming from environmental sources different than those responsible for smaller fluctuations, but seems to represent the tail of a continuous distribution of environmental perturbations.

Understorey insectivorous birds are highly vulnerable to different forms of habitat disturbance in tropical forests. Here we examine the effects of an unprecedented surface fire on understorey insectivores and forest litter arthropods in a terra firme forest of central Brazilian Amazonia, and compare species and guild abundance both close to and far from the clearly distinguishable fireline separating burnt and unburnt forest. All six of the most abundant insectivorous foraging guilds examined were detrimentally affected by fire, with dead-leaf gleaners and professional ant-followers being the most heavily affected. While army ants were apparently absent from the burnt forest, results from pit-fall traps showed that wildfires had only a limited effect on the abundance of most leaf-litter invertebrates. The fireline appeared to be an abrupt barrier to many understorey insectivorous birds, and there was little evidence to suggest that primary forest species were recolonizing burnt forest up to 1 year after the fires. Factors affecting the capture frequency of insectivorous birds are discussed.

We sampled blood from free-living spotted salamanders (Ambystoma maculatum) to test whether differences in the concentrations of a stress hormone (corticosterone) were associated with different qualities of breeding and migration habitat. Spotted salamanders are forest specialists that migrate to vernal pools to breed, and upland habitat degradation may have sub-lethal effects on animals that lead to population declines. An individual's level of physiological stress may function as a biomonitor for sub-lethal effects, and thus as a biomonitor for ecosystem quality. We compared unstressed (baseline) and stress-induced corticosterone concentrations in spotted salamanders: (1) at sites that differed in amount of forest loss; (2) during breeding migration across forest habitat versus pavement; (3) in microhabitats that varied in soil drainage and canopy cover. Removal of large amounts of terrestrial habitat surrounding a breeding pond was correlated with lower baseline (in males) and stress-induced corticosterone concentrations, which may indicate healthy individuals with a reduced ability to respond to additional stress or individuals experiencing chronic stress. Male salamanders migrating across pavement had elevated baseline corticosterone concentrations compared to animals migrating through a forest, consistent with an acute stress response. However, concentrations of corticosterone did not differ between individuals in microhabitats with canopy cover and well-drained soil versus those in microhabitats with no canopy cover and/or swampy soil. This endocrinological technique may be one useful measure of a population's health, helping to identify populations where further ecological study is recommended to evaluate conservation concerns.

Although the conservation of endangered species often implies the definition of priority areas for conservation, detailed information on their distribution patterns is seldom available over a large geographic range. The present paper explores the performance of an alternative data analysis approach, artificial neural networks, for assessing distribution patterns of endangered mammals when data are scarce and noisy. This approach was applied to identify wolf occupancy in Portugal based on information on wolf depredation and inquiries. Artificial neural networks were able to discriminate successfully between areas sporadically used by vagrant individuals and areas occupied by resident wolves, with a low estimated prediction error (around 1%). Only 33% of the wolf range is regularly occupied, being fragmented in five nuclei. These nuclei are surrounded by more disturbed marginal areas, with a source-sink dynamic between nucleus and marginal areas. Selection of priority areas for wolf conservation in the context of the Natura 2000 Network increased twofold the proportion of wolf regular range within protected areas. The good performance of artificial neural networks in assessing wolf distribution patterns suggests that this approach may be applied to other species where detailed records of distribution are limited.

Introduced predators are a leading threat to seabird populations world-wide and cats (Felis catus) have probably had the most universally damaging effect (Moors & Atkinson, 1984). Eradication of feral cat populations from seabird colonies is a conservation priority (Tershy et al., 2002) and there are many studies that demonstrate the benefits of these actions for seabirds (e.g. Forsell, 1982; Cooper et al., 1995). However, detailed estimates of the effects of cat predation on seabird population viability are lacking in spite of the fact that such data could provide important support for land managers attempting to promote eradication programmes for seabird restoration.

We show a direct impact of El Niño/Southern Oscillation (ENSO) related fires on the demography and persistence of the siamang (Symphalangus syndactylus), a frugivorous, Southeast Asian rainforest primate. Siamang groups affected by ENSO-related wildfires in a Sumatran rainforest were significantly smaller and experienced significantly lower infant and juvenile survival. Likelihood of infants surviving to subadults was higher by a factor of 2.8 for groups in undisturbed habitat. Burn groups had access to 48% fewer reproductive-size strangling fig trees in their territories, compared to non-burn groups. Dietary and foraging behaviour changes associated with habitat disturbance may result in lower productivity and higher mortality of young animals. Reproductive potential of burn groups is insufficient to offset low survival and groups are unlikely to persist for more than two generations. Increasing frequency of ENSO events increases the likelihood that siamang and other long-lived species that rely on fruiting trees will experience multiple fires within one generation; the resulting reduction in seed dispersal services will slow recovery of burned forest.

Minimum convex polygons (convex hulls) are an internationally accepted, standard method for estimating species' ranges, particularly in circumstances in which presence-only data are the only kind of spatially explicit data available. One of their main strengths is their simplicity. They are used to make area statements and to assess trends in occupied habitat, and are an important part of the assessment of the conservation status of species. We show by simulation that these estimates are biased. The bias increases with sample size, and is affected by the underlying shape of the species habitat, the magnitude of errors in locations, and the spatial and temporal distribution of sampling effort. The errors affect both area statements and estimates of trends. Some of these errors may be reduced through the application of α-hulls, which are generalizations of convex hulls, but they cannot be eliminated entirely. α-hulls provide an explicit means for excluding discontinuities within a species range. Strengths and weaknesses of alternatives including kernel estimators were examined. Convex hulls exhibit larger bias than α-hulls when used to quantify habitat extent and to detect changes in range, and when subject to differences in the spatial and temporal distribution of sampling effort and spatial accuracy. α-hulls should be preferred for estimating the extent of and trends in species' ranges.

The Cape Sable seaside sparrow (Ammodramus maritimus mirabilis) is Federally protected under the Endangered Species Act of the United States of America. This legislation prohibits direct or indirect take - the killing or harming - of the protected species. In 1993 and 1995, the opening of floodgates into Everglades National Park during the normal dry season resulted in a direct take of the sparrow. The argument was also made that there was indirect take through destruction of the habitat upon which the sparrow depends. Using a combination of fieldwork and satellite image analysis, we show that the floods did damage to the habitat of the sparrow. Moreover, they did so for a period longer than the actual flooding, further increasing the sparrow's extinction risk. Recovery of the sparrow population to pre-flood levels will require an adequate and stable amount of habitat. We now have a technique for monitoring that habitat and ensuring that poor water management does not threaten it. More broadly, this technique has the potential for monitoring the habitat of many other species and avoiding another situation such as the sparrow faces.

This paper applies the ‘choice experiment’ method to investigate public preferences over the design of wild goose conservation policy in Scotland. We argue that this method can shed useful light on the design of conservation policy, allowing policy-makers to take account of people's preferences, be they members of the general public (whose taxes often pay for conservation actions), local residents more directly affected by the policy, or visitors to wildlife areas. Preferences can be quantified in economic terms, so that the costs and benefits of different policy designs can be compared. In our study, we find that the general public, local residents and visitors have very different preferences for the conservation of geese. Whether geese are shot, the endangered status of geese, the spatial targeting of conservation and the size of the goose population all have impacts on the perceived benefits of conservation. In general, though, people are willing to pay for wild geese conservation.

Many species have strong habitat preferences that directly influence population viability. For successful reintroduction of threatened populations that rely on habitat structures, the correct placement of artificial structures is also important to population persistence. In this paper, we present a hierarchical approach to the problem of translocating animals that rely on permanent habitat structures, in which we first use population dynamics data to identify areas of suitable habitat, and then identify optimal configuration for habitat structures. We use data collected from a non-endangered, conspecific population of the endangered riparian woodrat (Neotoma fuscipes riparia) to examine the degree to which the distribution of dens in translocation sites might influence the likelihood that animals persist in their new environment. We characterize the habitats in which dens occur, analyze their spatial clustering, and compare them to temporal changes in population status for sex and age classes. We compare the potential efficacy of translocation efforts using spatial analysis versus solely habitat-based approaches and identify the optimal spatial configuration of dens that should be considered in this translocation effort. We found that patterns of habitat use were positively correlated with overstorey cover, and animal weight was positively correlated with understorey cover. Woodrats appear to select den locations on the basis of understorey cover, but also benefit from dense overstorey cover and distance to nearest tree. Our results suggest that in translocation efforts, artificial dens should be placed in clusters within a radius of 15 m, as values above and below this value showed negative correlations with body mass. Translocations should occur after reproductive events, which occur in April and August for woodrats in southern California. Our analyses provide practical guidelines in determining appropriate timing and spacing for translocation events in the context of animal condition, minimizing disease transmission, and reproduction.

The roan antelope (Hippotragus equinus) population inhabiting the Kruger National Park, South Africa, declined from 450 animals in 1986 to around 25 free-ranging animals subsequent to 1994. A computer simulation model was developed to: (1) evaluate likely contributions of low rainfall, habitat deterioration, population fragmentation and predation to the observed population decline; (2) project future likelihood of persistence of the population remnant, under various scenarios. Direct consequences of severe drought and habitat deterioration alone were inadequate to explain the observed decline, unless effects were more severe than assumed in the model. An increased predation loss to around 30% per year was needed. Persistence probability over 50 years was less than 0.5 if the predation loss remained above 20% per year. Models that take into account only stochastic uncertainty in demography and environmental variability are of limited reliability if potential changes in predation risk are not also accommodated.