We examined how several ecological factors influenced home-range size for 57 mountain lions inhabiting three regions of California. Our specific objectives were to investigate: (1) the relationship between home-range size and sex, age and reproductive status; (2) how broad-scale habitat differences and prey relative abundances influenced home-range size; (3) how seasonality, within these habitats, affected home-range size; (4) whether there was a significant relationship between body mass and home-range size. Results indicate that the effects of season on home-range size influenced the study areas differently. Both intrinsic factors, such as sex and body mass, and extrinsic factors, such as deer relative abundance and study site, influenced home-range size for mountain lions in this analysis. Linear relationships, however, between body mass and home-range size were not evident for any of our study locations. Curvilinear relationships, in contrast, existed between body mass and home-range size for all study areas during particular seasons, influenced strongly by animal sex. Conservation strategies designed to protect mountain lions and their habitats should reflect the above balance between intrinsic and extrinsic factors which influence home-range size.

Over the past 16 years, 13 new species of geoemydid turtles have been described from China. Ten of these new species are based on specimens purchased through the Hong Kong animal trade. Unfortunately, attempts by scientists to discover wild populations of some these newly described species have failed, raising questions about the legitimacy of the type localities and concerns over the validity of the species. Here the phylogenetic and taxonomic validity of two of these species is tested. Mitochondrial DNA haplotypes and allozyme genotypes of specimens matching the descriptions of Mauremys iversoni and Cuora serrata are compared to specimens of established species collected from known localities. The available evidence is consistent with the hypothesis that the specimens represent polyphyletic, intergeneric hybrids. The systematic status of all the new forms of turtles described from pet trade specimens are critical data for conservation efforts, particularly captive breeding.

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.

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.

The number of tiger subspecies is a major conservation issue that is difficult to resolve owing to small fragmented extant populations and limited historical samples in museums, which compromise the rigour of both molecular and morphological taxonomic studies. Rather than considering a static taxonomic approach to geographical variation in the tiger, we consider the changing biogeographical range of the tiger through the last glacial-interglacial cycle, based on habitat associations of modern tiger specimen records, and environmental reconstructions from the Last Glacial Maximum (LGM; approximately 20000 years before present (B.P.)). We regard this cycle as representative of the numerous glacial cycles that span the evolutionary history of the tiger since its appearance in the fossil record about two million years ago, thereby giving a deep-time perspective. The key issue is to determine the extent to which ancestral populations of the tiger were geographically isolated. If no geographical isolation is likely, and gene flow between tiger populations could be maintained until modern times, then diagnosably distinct populations could not have evolved. Our reconstructions show that only two tiger populations were likely to have experienced significant geographical isolation from the main species distribution; these were to the west of Tibet (during the LGM) and on Japan (throughout the glacial cycle). In addition, the LGM is likely to have seen the partial separation of peninsular Malayan and Sunda Islands tigers from mainland populations. From a biogeographical perspective it seems probable that only three contemporary populations were sufficiently separated for the evolution of distinct populations, which can be regarded as subspecies or evolutionary significant units. Therefore, most variation in modern tiger populations is probably clinal, which has important implications for future conservation strategies both in the wild and in captivity.

Successful invasive species often exhibit high phenotypic lability. Even when intuition suggests that their genetic diversity has been reduced by strong founder effects, many successful invasive species still exhibit adaptive change in response to their new environment. To understand the probable long-term ecological impacts of a particular invader, we need to quantify long-term changes in the invader's phenotype, as these changes may well influence the level of impact the invader has on native species. Here we examine morphological change, as a consequence of time since colonisation and other spatial factors, in the cane toad (Bufo marinus). Cane toads are highly toxic and have killed many Australian native predators since they were introduced in 1935. The amount of toxin to which a predator is exposed will depend upon (1) the body size of the toad and (2) the relative toxicity of the toad (here measured by the relative size of the toad's parotoid glands). Using multiple regression and a model-selection approach, we show that both toad size and relative toxicity have decreased with time since colonisation. Thus toads (like many other successful invasives) exhibit phenotypic lability. Importantly, this result strongly suggests that toads will exert their maximal impact on native predators when they first arrive in an area; the level of impact will then decline over time.

A significant proportion of the world's remaining dugongs (Dugong dugon) occur off northern Australia where they face various anthropogenic impacts. Here, we investigate the viability of two dugong meta-populations under varying regimes of indigenous hunting. We construct population viability analyses (PVAs) using the computer package VORTEX and published estimates of population sizes and hunting rates. In Torres Strait between Cape York and New Guinea, our models predict severe and imminent reductions in dugong numbers. Our ‘optimistic’ and ‘pessimistic’ models suggest median times for quasi-extinction of 123 and 42 years, respectively. Extinction probabilities are also high for eastern Cape York Peninsula. We demonstrate the inadequacy of reserves when harvest rates in neighbouring areas are high, identify the maximum harvest rates for meta-population stability and emphasise the urgent need for indigenous community involvement in management to establish sustainable rates of dugong harvest in these regions.

Manipulating family sex ratio is often possible, either through non-invasive methods like changing sex-determining ecological or social factors, or through more invasive methods such as hormone treatment of embryos or sperm sexing prior to using assisted reproductive technologies. If the number of available eggs limits population growth, the production of relatively more daughters than sons may eventually lead to increased population growth in terms of absolute numbers. However, any deviation of the effective sex ratio from equality increases the rate of inbreeding and the loss of genetic variance in the next generation. I show here that there is a range of female biased sex ratios where increased population growth outweighs the effect of an enhanced inbreeding rate during the first generation or the first few generations after the start of a sex ratio manipulation programme. This is especially so in small and declining populations, where some sex ratio manipulations not only increase the effective population number Ne, but also shift the population quickly into population numbers that are safe against the Allee effect. Consequently, an optimal sex ratio manipulation with respect to the genetic quality of a population means sending an endangered population first through a genetic bottleneck to achieve increased Ne, and hence decreased rates of inbreeding, in the long run.

The sensitivity of bat species to stochastic disturbance was investigated by exploiting the natural experiment provided by Hurricane Georges, which struck the island of Puerto Rico (Caribbean) in September 1998. Six forest habitats and three cave roost sites sampled for bats prior to the hurricane were sampled in the same way after the hurricane. Populations showed significant declines in abundance and species richness across all forest habitats sampled. Species' sensitivity to disturbance were not equal: larger species were significantly more affected by disturbance than smaller species, once the effects of phylogenetic non-independence were removed. There was some evidence that frugivorous and nectarivorous species are more affected by hurricane disturbance than insectivorous species. These findings have important implications for maintaining viable populations of species in areas that experience a high degree of environmental fluctuation.

One hundred and sixty-one river sites throughout the Thames catchment area were surveyed during the summer of 1995 and a number of habitat features were recorded in order to identify relevant habitat variables for the water vole (Arvicola terrestris; Arvicolidae). In addition, the role of the American mink (Mustela vision; Mustelidae) in determining the present distribution of water voles in the Thames region was investigated. The data were analysed by using generalized linear models (GLM).

Water voles were found in places characterised by low banks, unmodified channels, vegetated bars, submerged vegetation and were tolerant of moderate levels of bank reinforcement. The presence of mink was the most important variable. The results suggest that the American mink is the main factor determining the current distribution of water voles in this area. Restoration and recreation of habitat for water voles are likely to be a powerful tool in the recovery of water vole populations. It is hypothesised that mink control will be necessary only while the water vole population is small; once the population starts to increase both species could co-exist provided that the habitat is suitable.

Between 1990 and 1992, Mediterranean striped dolphins (Stenella coeruleoalba) suffered high mortality due to a morbillivirus epidemic. Ten highly variable microsatellite markers were used to assess the population structure of a sample of these stranded animals and to assess the genetic consequences of the epizootic on present stocks. We found little evidence of population structure within the Mediterranean, but distinct separation between this and the North Sea (Atlantic) population, the latter also showing greater genetic diversity. Using a genetic measure of inbreeding, we found that dolphins dying early in the outbreak were significantly more inbred than those dying later. Within 10 years of the end of the epidemic, the level of inbreeding among stranded dolphins had returned to its pre-outbreak levels. However, on average all stranded animals showed elevated levels of inbreeding, suggesting that animals dying from disease may venture towards the shore more than those dying of old age. Our results imply an important role for inbreeding in the dynamics of disease spread and that, in marine mammal research, caution should be exercised when inferring demographic parameters from stranded specimens.

Koalas have undergone a series of sequential founding events on islands in south-eastern Australia in recent times. Populations in South Australia at the Eyre Peninsula and Mt Lofty Ranges were founded in the 1960s from a colony on Kangaroo Island. The Kangaroo Is. colony was derived from animals introduced to French Island from mainland Victoria over a century ago. In this study, we first use microsatellite markers to quantify levels of genetic variation within the South Australian koala populations and the relatively unperturbed Strzelecki Ranges population from mainland Victoria. This analysis revealed low levels of allelic diversity (1.7 ± 0.2 to 2.7 ± 0.5) and heterozygosity (0.208 ± 0.088 to 0.340 ± 0.110) in the three South Australian koala populations relative to the Strzelecki Ranges population, which has the highest levels of allelic diversity (4.7 ± 1.1) and heterozygosity (0.476 ± 0.122) in Victoria. Second, we measured the incidence of testicular aplasia, a unilateral or bilateral failure in testicular development, in the Eyre Peninsula and Kangaroo Is. populations, and in the ultimate founding population at French Is. Testicular aplasia was present at a frequency of 4.3% in French Is., 12.8% in Kangaroo Is. and 23.9% in the Eyre Peninsula, but was undetectable in the non-bottlenecked Pilliga State Forest population of New South Wales. The incidence of testicular aplasia correlated positively with effective inbreeding coefficients derived from heterozygosity values (0.13 ± 0.06 in the Pilliga State Forest, 0.57 ± 0.17 in French Is., 0.63 ± 0.12 on Kangaroo Is. and 0.77 ± 0.12 in the Eyre Peninsula), which may indicate inbreeding depression. These findings are of concern when evaluating the long-term conservation and viability of the South Australian koala populations, which may benefit from genetic augmentation in the future. Finally, unconfirmed reports suggested that animals from other states in Australia were introduced into the Mt Lofty Ranges population. Therefore, we quantified differentiation between the three South Australian populations and the Strzelecki Ranges and French Is. populations, based on microsatellites and mtDNA d-loop region variation. R-statistics and Goldstein's delta mu square distance revealed that differentiation at nuclear loci between populations paralleled known recent population history, except for the close relationship between Mt Lofty Ranges and French Is. This suggested a recent contribution to the Mt Lofty Ranges populations of animals derived from the French Is. translocation program. Furthermore, mtDNA d-loop analysis found no evidence of contributions to the gene pool from animals of New South Wales or Queensland stock, implying that the population was derived exclusively from Victorian stock.

Non-invasive genetic sampling (NGS) is becoming a popular tool for population estimation. However, multiple NGS studies have demonstrated that polymerase chain reaction (PCR) genotyping errors can bias demographic estimates. These errors can be detected by comprehensive data filters such as the multiple-tubes approach, but this approach is expensive and time consuming as it requires three to eight PCR replicates per locus. Thus, researchers have attempted to correct PCR errors in NGS datasets using non-comprehensive error checking methods, but these approaches have not been evaluated for reliability. We simulated NGS studies with and without PCR error and ‘filtered’ datasets using non-comprehensive approaches derived from published studies and calculated mark–recapture estimates using CAPTURE. In the absence of data-filtering, simulated error resulted in serious inflations in CAPTURE estimates; some estimates exceeded N by[ges ]200%. When data filters were used, CAPTURE estimate reliability varied with per-locus error (Eμ). At Eμ=0.01, CAPTURE estimates from filtered data displayed <5% deviance from error-free estimates. When Eμ was 0.05 or 0.09, some CAPTURE estimates from filtered data displayed biases in excess of 10%. Biases were positive at high sampling intensities; negative biases were observed at low sampling intensities. We caution researchers against using non-comprehensive data filters in NGS studies, unless they can achieve baseline per-locus error rates below 0.05 and, ideally, near 0.01. However, we suggest that data filters can be combined with careful technique and thoughtful NGS study design to yield accurate demographic information.

The invasion of Britain by American mink has had a catastrophic impact on water vole populations. We surveyed and live-trapped water voles over 2 years in eight c. 25 km2 blocks in the upland of Scotland behind and ahead of the mink invasion front. Water voles had a similar distribution in the Grampian Mountains of north-east Scotland, on the edge of the invasion front, and in the Assynt area of north-west Sutherland well beyond the front. Water voles occurred in small, discrete colonies. Median nearest-neighbour distance between colonies was 0.6-0.7 km in both areas. Colonies experienced a high degree of turnover with extinction and colonization being commonplace and only a fraction of suitable sites were occupied at a given time. High dispersal rates connecting numerous (> 30) colonies over large areas (> 25 km2) enable water voles to persist in such circumstances. Synchronized fluctuations in occupancy not caused by mink also occurred at the regional scales of the Grampian Mountains and Assynt areas. Localized mink invasions have fragmented a previously continuous metapopulation into smaller clusters and this may indirectly affect the likely persistence of water vole colonies not directly exposed to predation by mink.

Approximately 40% of the world's leatherback marine turtles (Dermochelys coriacea) nest in Suriname and French Guiana. Trends in nest numbers reconstructed for the last 34 years indicate several up and down events. We undertook computer simulations to determine whether a density-dependent phenomenon might be involved because the period of high-density nesting coincides with a high level of nest destruction by nesting females. The parameters of density-dependent nest destruction were calculated for the Yalimapo-Awala beach. We show that: (1) density-dependent nest destruction occurs, but (2) it promotes a density-dependent feminization of hatchling sex ratio, and consequently (3) the global production of juveniles continues to increase in relation with the increasing number of deposited nests even for the highest densities observed at that beach. Mean annual production of female hatchlings per adult female, although density dependent, is less than two juveniles even at the lowest densities of nesting females.

Genetic adaptation to captive environments is likely to reduce the reproductive fitness of endangered species when they are reintroduced into natural environments. Equalization of family sizes is predicted to halve genetic adaptation to captivity as it removes selection among families and is recommended in captive management of threatened species. This prediction was evaluated by comparing the reproductive fitnesses of replicate populations of Drosophila maintained using either equal (EFS) or variable family sizes (VFS) for 25 generations in captivity under uncrowded conditions on a medium containing CuSO4. After 25 generations, EFS populations produced 8.8% more offspring per pair than their outbred base population on CuSO4 medium, while VFS produced 17.5% more. Consequently, the rate of genetic adaptation to captivity in EFS was about half that in VFS, as predicted. In simulated ‘wild’ conditions (crowded, competitive conditions on medium lacking CuSO4), both treatments showed much lower reproductive fitness than their outbred base population, the reductions being 38% in EFS populations and 43% in VFS populations. Surprisingly, reproductive fitness of the two treatments did not differ significantly under these conditions. These results raise doubts about the ability of equalization of family sizes to reduce genetic deterioration that adversely affects reintroduction success for captive populations of endangered species.

The endemic pink pigeon has recovered from less than 20 birds in the mid-1970s to 355 free-living individuals in 2003. A major concern for the species' recovery has been the potential genetic problem of inbreeding. Captive pink pigeons bred for reintroduction were managed to maximise founder representation and minimise inbreeding. In this paper, we quantify the effect of inbreeding on survival and reproductive parameters in captive and wild populations and quantify DNA sequence variation in the mitochondrial d-loop region for pink pigeon founders. Inbreeding affected egg fertility, squab, juvenile and adult survival, but effects were strongest in highly inbred birds (F≥0.25). Inbreeding depression was more apparent in free-living birds where even moderate levels of inbreeding affected survival, although highly inbred birds were equally compromised in both captive and wild populations. Mitochondrial DNA haplotypic diversity in pink pigeon founders is low, suggesting that background inbreeding is contributing to low fertility and depressed productivity in this species, as well as comparable survival of some groups of non-inbred and nominally inbred birds. Management of wild populations has boosted population growth and may be required long-term to offset the negative effects of inbreeding depression and enhance the species' survival.

There are many methods available for evaluating conservation priorities. Traditional methods of species richness, genus richness and critical species counts were compared with newer methods of phylogenetic and genetic diversity. Conservation priorities for areas designated by the Interim biogeographic regionalisation for Australia (Thackway & Cresswell, 1995) were assessed on the basis of the freshwater crayfish fauna of Australia. Distributions for all crayfish species were taken from the literature, and plotted in the IBRA areas. Species and genus richness, as well as the number of rare or endangered species were calculated for each area. A phylogeny of 35 representative crayfish based on 16 S rDNA sequence data was used to assess phylogenetic and genetic diversity of species and genera. Methods of species richness and phylogenetic diversity agreed to a large extent in their ranking of areas, both methods agreed that the north-west coast of Tasmania and the south-eastern portion of the continent were of highest priority for conserving the greatest amount of diversity. These results differ greatly from high priority areas based on other taxonomic groups, emphasizing the importance of broad taxonomic and ecological sampling in making conservation decisions.

The relationship between population size and temporal variability in population size was examined using 2387 populations of 203 species from the Global Population Dynamics Database. Population variability, relative to population size, was assayed by regressing the standard deviation of population size against mean population size. Linear regression produced slopes that were less than one in 165 of 203 species. Thus, temporal fluctuations in population size became significantly weaker as population size increased. Similarly, the slope was significantly less than one for a single regression including all 2387 populations, regardless of taxonomic classification. The slopes of the regression lines did not differ for major taxonomic groupings, but the Y-intercept was significantly lower for birds than for the other taxonomic groupings. Factor analysis was used to examine the highly correlated parameters: data reliability, population size and taxonomic lineage. Population size was obviously the most important parameter affecting temporal variation in population size, data reliability was also very important, but taxonomy was of little or no importance. The relationship between temporal variation in population size and mean population size, predicted from the data, was used to predict the probability of extinction assuming a normal distribution of population sizes. This simple model predicts that populations of vertebrates will have to number in the thousands for long-term conservation to be effective.

Osmoderma eremita, an endangered beetle restricted to hollow trees, was surveyed in stands of different size, isolation and physical characteristics in an area in south-eastern Sweden. To infer habitat occupancy the presence/absence of fragments of adult body parts was used. Mark–release–recapture of adults with pitfall traps set in tree hollows was carried out to estimate local population size. Habitat occupancy/tree was higher in larger stands than in smaller stands, but there was no correlation between occupancy/stand and isolation of stands. This suggests dispersal is important in the population processes within stands, but not between stands. Osmoderma eremita was found in most of the larger stands and this probably mirrors the fact that the density of old-growth oaks has been much higher in the area than today. Habitat fragmentation over the last two centuries has disrupted the network of habitat patches, thus preventing dispersal into smaller, younger stands. A minimum number of suitable trees aggregated in stands seems to be necessary to provide long-term viability of local O. eremita populations. To preserve viable O. eremita populations, it is therefore necessary to increase size and connectivity of stands with hollow trees.