We studied variables affecting spatial and inter-annual variations in presence/absence and abundance of little bustard (Tetrax tetrax) males in extensive cereal farmland in central Spain. Both variables were positively influenced by the percentage of arable surface and also by substrate heterogeneity. In addition, male abundance varied significantly between years and among sectors of the study area, even when taking into account variation in landscape variables. A significant interaction between year and sector showed that abundance variations did not follow a fixed pattern, meaning that interannual variation in male abundance among sectors cannot be predicted. We discuss potential alternatives to explain such variation, as well as the implications of our results for the species' population estimates, status assessment and conservation.

The current study investigates whether a simple measure of taxonomic diversity (Taxonomic Distinctiveness (TD)) can be used as a proxy for different measures of phylogenetic diversity (Phylogenetic Distinctiveness (PD)) in determining species of regional conservation priority, and uses extant South African Chiroptera and Carnivora as a case study. Published phylogenies for the two mammalian Orders allowed the quantification of a node-based measure that was considered to represent phylogenetic diversity (PDNODE), as well as a branch length-based measure that was considered to represent the amount of evolutionary change over time (PDBRANCH). Both the PDNODE and PDBRANCH, together with TD were included in our regional conservation priority assessment. Although no statistically significant differences were detected between the PDNODE, PDBRANCH and the TD for both the Chiroptera and Carnivora, these measures were also shown to be correlated with each other. More importantly, inclusion of either the PDNODE, PDBRANCH, or TD in our analysis did not significantly alter the species that were identified as being of regional conservation priority. Both regional priority scores for the South African Chiroptera and Carnivora and their respective rankings were broadly consistent across the three potential indicators of conservation status utilised. These results suggest that the inclusion of either the PDNODE and/or PDBRANCH in conservation prioritisation exercises may not add value to that currently provided by the TD. Consequently, this implies that in the absence of relevant PD data, the utilisation of the TD in regional conservation priority settings may provide the appropriate information on evolutionary diversity.

Cyclura lewisi is an endangered rock iguana endemic to the island of Grand Cayman. Like many other animals, C. lewisi increasingly depends on modified landscapes for its survival. The remaining natural population is too small and fragmented to yield information on the natural history and population biology of this species. Therefore, we studied habitat use in a population of captive-bred, released iguanas in a botanic park. Compositional analysis was used to examine habitat selection and use by iguanas at two scales: selection of home range within the landscape and selection of locations within home ranges. At both scales and for all time periods examined, iguanas preferred modified habitat to natural habitat. Subhabitats were examined only at the scale of selection within the landscape, for which iguanas showed preference in some but not all time periods. Iguanas used artificial retreats more often than natural retreats and commonly occupied retreats in modified areas. Many female iguanas nested in artificial sites within the park. The use of modified habitats and artificial retreats and nests by reintroduced C. lewisi is encouraging, because this and other species of Cyclura may depend on these resources for future survival.

A set of priority sites for wildfowl conservation in Mexico was determined using contemporary count data (1991–2000) from the U.S. Fish & Wildlife Service mid-winter surveys. We used a complementarity approach implemented through linear integer programming that addresses particular conservation concerns for every species included in the analysis and large fluctuations in numbers through time. A set of 31 priority sites was identified, which held more than 69% of the mid-winter count total in Mexico during all surveyed years. Six sites were in the northern highlands, 12 in the central highlands, six on the Gulf of Mexico coast and seven on the upper Pacific coast. Twenty-two sites from the priority set have previously been identified as qualifying for designation as wetlands of international importance under the Ramsar Convention and 20 sites are classified as Important Areas for Bird Conservation in Mexico. The information presented here provides an accountable, spatially-explicit, numerical basis for ongoing conservation planning efforts in Mexico, which can be used to improve existing wildfowl conservation networks in the country and can also be useful for conservation planning exercises elsewhere.

Only one of the 5000 extant louse species (Phthiraptera) and no species of flea (Siphonaptera), parasitic helminth (Platyhelminthes), parasitic nematode (Nemata), mite, or tick (Acari) is listed as threatened by the IUCN, despite impassioned pleas for parasite conservation beginning more than a decade ago. Although they should be conserved for their own sake, past arguments, highlighting the intrinsic and utilitarian value of parasites, have not translated into increased attention by scientists or conservation managers, at least by the standard of listing for protection. Here, the use of estimated genealogies and population genetic patterns of parasites to illuminate their hosts' evolutionary and demographic history is advocated. Parasite DNA generally evolves more rapidly than their hosts', which renders it an underexploited resource for conservation biologists, particularly in cases where the hosts' genealogy or degree of population genetic structure is difficult to measure directly. Moreover, parasite gene flow may occur during host dispersal irrespective of host gene flow, revealing host movement through space and time. Parasite ecology and evolution may thus become another tool for the management of endangered vertebrate populations. This will result in the recognition of new host records, parasite species and cryptic lineages, which will help lift the veil of ignorance with respect to parasite biodiversity.

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.

Taxonomic bias has been documented in general science and conservation research publications. We examined whether taxonomic bias is similarly severe in actual conservation programmes as indicated by the focus of species reintroduction projects worldwide. We compiled a database of reintroduction projects worldwide, yielding a total of 699 species of plants and animals that are the focus of recent, current or planned reintroductions. Using IUCN (World Conservation Union) data for total numbers of known species worldwide, we found that vertebrate projects were over-represented with respect to their prevalence in nature. Within vertebrates, mammals and, to a lesser extent, birds, were over-represented, whereas fish were under-represented. This over-representation extended to two mammal orders, artiodactylids and carnivores, and to four bird orders, anseriforms, falconiforms, gruiforms and galliforms. For neither mammals nor birds was reintroduction project bias related to any differences between orders in vulnerability to threat. Bird species that are the focus of reintroduction efforts are more likely to be categorised as ‘Threatened’ than expected on the basis of the distribution of all known species over all threat categories, however, nearly half of all bird species being reintroduced are classified as ‘Least Concern’. The selection of candidates for reintroduction programmes is likely to consider national priorities, availability of funding and local community support, over global conservation status, While a focus on charismatic species may serve to garner public support for conservation efforts, it may also divert scarce conservation resources away from taxa more in need of attention.

Percentage canopy cover data derived from Landsat Enhanced Thematic Mapper (ETM+) sensor data, validated with field measurements, provide a useful tool for delineating Myanmar's Eld's deer (Cervus eldi) habitat. The current extent and condition of remaining Eld's deer habitat is unknown, but the species prefers dry dipterocarp forest. This habitat type has widely varying canopy cover and cannot be accurately delineated with traditional remote sensing techniques. New maps based on estimates of percentage canopy cover represent the variability of dry dipterocarp forests more accurately than maps of strict classes of habitat. Over 500 field measurements of canopy cover were used to train Landsat ETM+ data that were analysed with regression-tree analysis. The resulting satellite-based estimates of canopy cover were compared with an independent set of field validation points (r=0.539, P<0.001, n=114). The satellite-based estimates also showed potential for predicting the presence of Eld's deer (r=0.636, P<0.01, n=14). The results from the predictive maps are in accordance with previous field studies demonstrating the species' preference for dense, dry dipterocarp forest. Patterns of percentage tree-canopy cover across the study area were negatively correlated with human population density (r=-0.307, P<0.001, n=223), suggesting potential further threats to Eld's deer populations if the human population continues to grow.

The little bustard (Tetrax tetrax) has declined rapidly across European farmland landscapes due to agricultural intensification. In France, the number of breeding males in agricultural habitats has been reduced by 92% over the last 20 years as a result of decreases in insect abundance and nest destruction during harvesting. An age- and sex-structured stochastic metapopulation model was formulated for the remaining little bustard population in south-west France and, using actual estimates of demographic rates obtained after 1997, its extinction risk over the next 30 years was estimated to be ca. 0.48. Limited population reinforcement has thus appeared as a potential conservation strategy for this species in agricultural habitats, while agro-environmental actions have begun to have an effect on habitat quality at the landscape level. Different strategies for the reinforcement of fledglings, including the number and frequency of releases and the number of release localities in relation to four criteria for choosing the release points, were evaluated in terms of their effect in reducing the extinction risk of local populations and of the metapopulation. The reinforcement of 100 fledglings per year for 5 years and choosing the actual release points using the current abundance were found to be the optimal choices for reducing the estimated extinction risk of the remaining little bustard population in south-west France.

Populations established with a small number of founders are thought to have a high risk of extinction due to allee effects, demographic stochasticity, inbreeding and reduced genetic variation. We tested whether the initial number of birds released was related to persistence in reintroductions of saddlebacks (Philesturnus carunculatus) and robins (Petroica australis) to New Zealand offshore islands. Data were analysed for 31 populations that had been observed for at least 3 years since reintroductions. The numbers released ranged from 5–188. Most of the populations (26) survived and grew, including five from less than 15 founders, and four out of the five extinctions were attributable to introduced mammalian predators. The number of individuals released did not significantly affect extinction probability. The ability of these small releases to establish populations can be attributed to the closed nature of the islands (allowing birds to find mates), low mortality rates following release and high growth rates at low density. Stochastic simulation models based on data from two reintroduced populations suggested that populations with four founders (two male, two female) would have a negligible chance of extinction through demographic stochasticity and would be able to grow even if there were high rates of egg failure through inbreeding.

We studied the influence of vegetation structure and tree phenology on bird communities along a gradient of tropical forest degradation in NW Madagascar. Birds were censused by point counts at Ankarafantsika, one of the largest remnants of the severely reduced dry deciduous forest. The original forest was dominated by foliage insectivores. A few years after wildfire, regrowth was dense, most forest bird species were still present and additional understorey species appeared. As a result, species richness and abundance per point count increased. In contrast, when forest was transformed into savanna, the avian assemblage became poor, dominated by granivores and aerial insectivores, with only seven species shared with the original forest. Foliage volume, grass volume and bare ground cover explained most of the bird community variation by means of canonical correspondence analysis. Birds tended to increase their habitat breadth along the forest–savanna gradient. An index of bird conservation value, including abundance, endemism and the threatened status of the species, was highest in burned forests (1.12), intermediate in unburned forests (1) and lowest in savanna (0.44). The results emphasise the urgent need to protect not only the undisturbed fragments, but also the burned dry forests, because of their high value for biodiversity.

The present study reports the first population genetic analysis of Arapaima gigas, an important but critically over-exploited fish species of the Amazon basin. We sequenced two discontinuous mitochondrial DNA regions of 1204 base-pairs (bp) (NADH1 segment) and 1143bp (ATPase segment) from 139 individuals of A. gigas representing eight localities spanning the Amazon basin from Iquitos, Peru to Macapá, Brazil. We discovered 34 haplotypes separated by 44 segregating sites. The two most common haplotypes are shared among all populations and isolation-by-distance appears to be the most important population dynamic, although there is no significant association between geographical distance and genetic differentiation. Observed patterns of differentiation appear to be attributable largely to anthropogenic factors associated with over-exploitation. Greatest haplotypic diversity exists upstream of Manaus and in areas away from large centres of population. The female variance and inbreeding effective population sizes are approximately 150000 individuals and localities in the Amazon basin are connected by gene flow. Naturally low levels of population differentiation and relatively high between-population connectivity is encouraging for the conservation and management of A. gigas. If strategically placed biological reserves were created throughout the Amazon basin to act as sources of emigrants within a source–sink metapopulation model, we believe locally depleted populations can be re-populated and maintained by individuals immigrating from these reserves.

The number and extent of human settlements around the world are increasing as the human population grows and people move from rural to urban areas. The decline and ultimately the local extinction of many indigenous species from a range of taxonomic groups within urbanised areas is a recurring theme from cities around the world. However, determining whether a species has become extinct can be difficult because sufficient survey effort may be too costly and expert opinion may involve considerable subjective bias. In this study, we compared the results of four quantitative assessments of the probability of persistence of indigenous mammals within Melbourne, Australia. Our comparisons were methodological, taxonomic and spatial. Less than half (26) of the original 54 species that occurred in Melbourne prior to European settlement have a greater than 95% probability of being extant at the end of 2000. Mammals occurring in local government areas (LGAs) within 10km of the central business district of Melbourne were less likely to be extant, with 29% of species having a greater than 95% probability of persisting, compared to 48% in the outer LGAs. The group of species most negatively affected by urbanisation were the small, ground-dwelling mammals, with just two out of 15 species having a greater than 10% probability of persisting. All four methods gave broadly similar results, with the Bayesian approach consistently suggesting higher probabilities of species persistence. The decline in the number of species is likely to continue with the ongoing expansion of Melbourne. The greatest opportunity to conserve the maximum number of species of mammal within Melbourne is in the outer LGAs where they remain extant. We recommend that state and local governments design and adopt a comprehensive strategy for managing habitat networks that cross jurisdictional boundaries and encompass the greater Melbourne area to enhance prospects for the survival of mammals.

We reintroduced 33 peregrine falcons (Falco peregrinus) at two release areas with contrasting habitat configurations to assess landscape influences on dispersal. One site (Daniel Boone National Forest) had non-forested corridors within a forest matrix, whereas the other site (Tom Dorman State Nature Preserve) had forested corridors within an agricultural matrix. We used aerial telemetry and ground observation to assess differences in dispersal between sites and we used multivariate statistical analyses to detect combinations of response variables depicting landscape influences. Non-forested corridors at Daniel Boone affected post-fledging movements and initiation of dispersal, whereas no discernable pattern in dispersal initiation was observed at Dorman Preserve. Results included significant (p<0.05) differences between peregrines at Daniel Boone and Dorman Preserve in $\bar{x}{\pm}$ SD post-fledging area (PFA) size (2643.5±2599.0 and 931.7±732.1 ha, respectively), maximum movement distances (12.9±13.9 and 6.1±4.6 km, respectively), orientation of movements (second-order $\bar{x}$ angle±95% confidence interval (CI)=280.8±58.6 (non-random orientation) and 358.8±98.8 (random orientation), respectively), time spent on the PFA (16.0±12.2 and 31.0±3.3 days, respectively) and selection of agricultural habitats (Euclidean distance vectors ρ=0.66 and ρ=2.50, respectively). Selection of agriculture by peregrines released on Daniel Boone reflected selection of corridors as part of pre-dispersal movement. These results, coupled with generally unorientated movement behaviour by Dorman Preserve peregrines, provided evidence for an influence of functional landscape connectivity on dispersal in peregrines.

The eastern spotted skunk (Spilogale putorius) was once common throughout the midwestern and southeastern United States, with consistent annual range-wide harvests of [Gt ]100 000 animals. In the 1940s, however, populations seemingly crashed and the species is currently listed by various state agencies as endangered, threatened, or ‘of concern’ across much of its range. We examined long-term harvest records from 10 states to better understand the 20th century population dynamics of eastern spotted skunks, to discern whether the putative decline was biologically real or an artifact of altered harvest pressures and to identify the timing of the decline. Analyses reveal unequivocally that the species was indeed once common in the Great Plains. Beginning in about 1940, harvests dramatically declined, although the onset of declines differed between states. By the early 1950s total harvests in all states were <10% of pre-crash harvest. Thereafter, rates of decline slowed, but nevertheless continued, such that by the 1980s harvests were <1% of those during pre-decline years. Analyses show that these declines are real and not an artifact of harvest effort. Although the causes of the decline remain unclear, the analyses suggest a need for immediate attention to address the long-term persistence of this species.

Hispaniola has been identified as a global priority for avian conservation. However, little quantitative information has been available to help guide optimal strategies for conservation action on the island. Here, the first broad-scale look has been assembled of the distribution of species of conservation concern among protected areas in Haiti and the Dominican Republic and their occurrences have been analysed to determine where conservation activities might be focused to serve avian conservation interests. An iterative, heuristic complementarity approach was used, such that the most highly ranked reserve is that which protects the greatest number of species of conservation concern and subsequently ranked reserves are those that add the most species of conservation concern that are not included in the first reserve. Parks are prioritised by the presence/absence of species of concern and prioritised a second time with individual species first being weighted by species-specific extinction risks and then by uniqueness in terms of endemism at the island or regional level. Parks of highest importance are the Sierra de Bahoruco National Park and Jaragua National Park, but the importance of other protected areas to avian conservation is also documented and discussed.

Substantial genetic variation is hypothesised to be necessary for the long-term survival of species. Therefore, a major aim in conservation is to maintain and restore variation in small and endangered populations. However, in most populations the amount of genetic variation and, thus, the potential threats posed by limited variation are unknown. In the present study, we assess genetic variation, both at 10 microsatellite loci and at the major histocompatibility complex (MHC), in three closely related Acrocephalus warbler species with contrasting demographies. We found that the recently bottlenecked, island endemic, Seychelles warbler (A. sechellensis; SW) has substantially reduced microsatellite and MHC diversity compared to the widespread great reed warbler (A. arundinaceus; GRW). In contrast, another endangered species with a small breeding range, the Basra reed warbler (A. griseldis; BRW), harboured as much variation as did the GRW. This suggests that significant genetic variation and, therefore, adaptive potential, remains in the BRW – a situation that should hold as long as its habitat and numbers are maintained. Our study is one of the first to assess genetic variation at both ‘non-critical’ microsatellite markers and ‘critical’ MHC loci within endangered species. The two types of loci provided a similar picture of the genetic variation in the species we studied, but this has not been the case in studies of some other species. Using a combination of specific functional loci and genome-wide random markers appears to be the best way to assess the threat posed by reduced genetic diversity.

For selected species, conservation breeding has become integrated into recovery plans, most often through the production of offspring for reintroduction into nature. As these programs increase in size and scope, it is imperative that conservation managers retain the biological integrity of the species. This study investigated the causes of morphological changes that are known to occur in black-footed ferrets (Mustela nigripes) maintained ex situ. In a previous study, ferrets maintained in captivity were 5–10% smaller in body size than pre-captive, in situ animals. In the present study, the authors compared nine morphological characters among ex situ animals and their in situ descendants. Within the ex situ population, cage types were compared to determine whether housing influenced morphometry. Black-footed ferrets born to reintroduced individuals quickly returned to their pre-captive size suggesting that a diminutive morphology ex situ did not have a genetic basis. Furthermore, cage type affected overall body size and shape; ulnas and tibias were as much as 9% shorter for ex situ animals. The authors hypothesise that small cage size and environmental homogeneity inhibit the mechanical stimuli necessary for long bone development. These findings have ramifications for ex situ managers who need to create artificial captive settings that promote natural physical development. In the absence of such an environment, ‘unnatural’ morphologies can result that may contribute to poor fitness or perhaps even domestication.

Rana iberica is an Iberian endemic with populations mainly distributed in northwestern Iberia, but with scattered populations along the Sistema Central in central Spain. These latter populations inhabit mostly mountain areas and are endangered due to habitat loss and fragmentation. At present, no information about genetic variability and gene flow patterns between populations is available and, consequently, it is unknown to what extent geographical fragmentation might have caused restrictions to gene flow. We used six microsatellite loci to characterise genetic variability in R. iberica populations from the Sistema Central. We analysed samples of 142 specimens from 15 populations in this region and another two from additional locations in the Iberian Peninsula. The number of alleles per locus observed ranged from four to 15. Allelic richness, percentage of private alleles and gene diversity was significantly lower in populations from the Sistema Central, where inbreeding coefficients were relatively high. Analysis of molecular variance (AMOVA) and estimated FST values indicated the existence of genetic substructuring within this region and suggested the existence of restrictions to gene flow in geographically close populations. Low heterozygosities and a trend towards lower values of genetic variability from western to eastern populations within the Sistema Central suggest that R. iberica has colonised this region recently. We hypothesise that the observed pattern is due to the interaction of both historical (reduced genetic variability in peripheral populations) and present-day (anthropogenic habitat loss) factors that confirm the vulnerable status of populations of R. iberica in central Spain and point to the need for adopting measures directed towards the preservation of existing habitat.

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.