Most large native carnivores have experienced range contractions due to conflicts with humans, although neither rates of spatial collapse nor expansion have been well characterised. In North America, the grizzly bear (Ursus arctos) once ranged from Mexico northward to Alaska, however its range in the continental USA has been reduced by 95–98%. Under the U. S. Endangered Species Act, the Yellowstone grizzly bear population has re-colonised habitats outside Yellowstone National Park. We analysed historical and current records, including data on radio-collared bears, (1) to evaluate changes in grizzly bear distribution in the southern Greater Yellowstone Ecosystem (GYE) over a 100-year period, (2) to utilise historical rates of re-colonisation to project future expansion trends and (3) to evaluate the reality of future expansion based on human limitations and land use. Analysis of distribution in 20-year increments reflects range reduction from south to north (1900–1940) and expansion to the south (1940–2000). Expansion was exponential and the area occupied by grizzly bears doubled approximately every 20 years. A complementary analysis of bear occurrence in Grand Teton National Park also suggests an unprecedented period of rapid expansion during the last 20–30 years. The grizzly bear population currently has re-occupied about 50% of the southern GYE. Based on assumptions of continued protection and ecological stasis, our model suggests total occupancy in 25 years. Alternatively, extrapolation of linear expansion rates from the period prior to protection suggests total occupancy could take >100 years. Analyses of historical trends can be useful as a restoration tool because they enable a framework and timeline to be constructed to pre-emptively address the social challenges affecting future carnivore recovery.

Extirpated from the wild in 1972 by overhunting, Arabian oryx (Oryx leucoryx) were re-introduced in Saudi Arabia in March 1990; 17 oryx were released into Mahazat as-Sayd, a 2244 km2 fenced reserve in west-central Arabia, which lies at the periphery of their historical home range. The population has increased to 346 animals. The National Commission for Wildlife Conservation and Development, and those that manage the herd, have recently asked, ‘What is the optimal management strategy to assure long-term persistence of the species, given the absence of immigration and predation?’ Food resources, determinants of rates of mortality and birth, covary with unpredictable rainfall in Mahazat as-Sayd. Using data-driven assumptions, we developed a computer model that evaluated the probability of extinction (Pex) under various management strategies: no intervention, removing a fixed number of animals each year, removing a fixed percentage of animals each year, and removing all individuals above a threshold. In addition, we explored the probability that oryx populations would decline below two thresholds, called the probability of quasi-extinction (Pq-ex) under various management schemes. Our analyses suggested that, without intervention, the oryx population had a high Pex. Removing 15% of the current population provided a low Pex, but this method also produced high values for Pq-ex and, as a by-product, wide fluctuations in population size (N). Although it required an assessment of both N and carrying capacity (K), the most successful management plan consisted of removing all oryx above 70% of K. Adoption of this plan resulted in low Pex, low Pq-ex, and smaller fluctuations in N. Our study may provide a useful model for evaluating management plans for a variety of threatened animal populations in desert ecosystems.

The analysis of habitat selection underlies many conservation recommendations. Different researchers use different methods, therefore there is a need to examine whether the results are consistent. This study examined habitat selection by lesser kestrels, Falco naumanni, a globally threatened species, using two methods: visual sighting data from a 35-km transect and radio-telemetry of 33 birds. Habitat use and spatial ecology were studied across all of the breeding season in a pseudo-steppe area, where traditional agro-grazing systems are still present but some areas have been transformed into pine plantations. Telemetry data indicate that, in good quality habitat, lesser kestrels prefer to forage close to the colony. Furthermore, the home ranges obtained were smaller than those for lesser kestrels using intensively managed habitats or more forested areas. Habitat availability was determined within a 4-km radius of the colony and habitat preferences were determined using compositional analysis. Both methods were found to produce similar results, but telemetry provided a larger number of significant differences between habitats. Before the chicks hatched, lesser kestrels preferred grazed fallows, ploughed fields and cereal, while after hatching cereal stubble was the preferred habitat. In steppe habitats the protection of such foraging habitats within a 3-km radius from the colonies could be a very effective conservation measure.

The Preble's meadow jumping mouse (Zapus hudsonius preblei) is listed as a threatened subspecies under the United States Endangered Species Act (US-ESA). The quantitative description of this subspecies was based on cranial measurements of only three adult specimens. It is one of twelve subspecies of Z. hudsonius and is a peripheral population at the western edge of its range. We tested the uniqueness of Z. h. preblei relative to other nearby subspecies of Z. hudsonius using a hypothesis testing approach and analyses of cranial morphometric, mtDNA sequence and nuclear microsatellite data obtained from museum specimens and archived tissues. Morphometric analysis of variance did not support the original description of Z. h. preblei as a subspecies. Principal component analysis of these data showed Z. h. preblei within the range of variation found in Z. h. campestris and Z. h. intermedius. Discriminant analysis correctly classified only 42% of Z. h. preblei skulls at jackknifed posterior probabilities >0.95 relative to Z. h. campestris. All mtDNA haplotypes found in Z. h. preblei were also found in Z. h. campestris. Simulation based estimates of current and historical gene flow (MDIV) revealed low, but non-zero, mtDNA gene flow among Z. h. preblei and several nearby subspecies. Analyses of five nuclear microsatellite loci using population pairwise FST, BAPS and STRUCTURE were consistent with morphometric and mtDNA results. These revealed low levels of genetic structure and evidence of recent gene flow and bottlenecks in Z. h. preblei. Due to a lack of clearly recognisable genetic, morphological, or adaptive differences, we synonymise Z. h. preblei and Z. h. intermedius with Z. h. campestris. We suggest that candidates for listing under the US-ESA, or similar biodiversity laws, be evaluated for genetic and/or morphological uniqueness to prevent the misallocation of resources to non-distinct taxa like Z. h. preblei.

Bat activity was quantified in 15 historic landscape parks in England to assess the importance of habitat features within them for foraging bats. Unimproved grassland, water and plantation woodland were selected (used more than expected based on availability) by all bat species. Pipistrellus pipistrellus selected unimproved grassland and areas around water; Pipistrellus pygmaeus selected semi-natural woodland and tree lines; ‘Myotis group’ bats, (including Myotis spp., Plecotus spp. and Barbastella barbastellus) selected water and plantation woodland; and ‘Nyctalus group’ bats (including Nyctalus spp. and Eptesicus serotinus) selected unimproved grassland and parkland. The relative area of watercourses and tree lines in the landscape parks was the best predictor of bat activity. Landscape parks including unimproved grassland, water, parkland, semi-natural woodland, plantation woodland and tree lines have the most potential for foraging bats, and may form favourable ‘islands’ in intensively managed agricultural landscapes. To maximize the conservation value of historic landscape parks for bats, these habitats should be conserved or created.

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.

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

Fluctuating asymmetry (FA), a measure of developmental stability, has been proposed as a simple technique for identifying populations suffering from inbreeding and a loss of genetic diversity. However, there is controversy regarding the relationship between FA and both allozyme heterozygosity and pedigree inbreeding coefficients (F). FA of sternopleural bristle number in Drosophila melanogaster was measured in populations maintained at effective sizes of 25 (8 replicates), 50 (6), 100 (4), 250 (3) and 500 (2) for 50 generations (inbreeding coefficients of 0.05—0.71). FA was calculated from the same data set using three different indices (FA1, FA5 and FA6). There was no significant relationship of FA with pedigree inbreeding coefficients for any of the three indices. The relationship between FA and allozyme heterozygosity was non-significant for indices FA5 and FA6 (the more powerful indices) and only significant for FA1. A second comparison of highly inbred (F ≈ 1) populations with their outbred base population showed significantly greater FA in the inbred populations only when analysed with FA6. Analysis of the same data using FA1 and FA5 showed non-significant relationships in the opposite direction. If a relationship between FA and genetic diversity does exist, it is weak and inconsistent. Consequently, our results do not support the use of FA as a monitoring tool to detect inbreeding or loss of genetic diversity.

The unique butterfly species, Baronia brevicornis, perhaps the oldest taxon in the Papilionidae, is known to have a very restricted distribution in Mexico. Populations are restricted to southern Mexico in deciduous scrub forest where its host-plants, Acacia trees (Leguminosae), are common and widespread. Little is known of the conservation implications of its relationship with its host trees. We recorded fine scale population data for larval and adult B. brevicornis in 22 km2 of fragmented landscape in southern Mexico. Habitat associations determined from over 1319 transect walks reveal that B. brevicornis exhibited an extremely localised distribution, occupying < 1% of the study area and being mostly associated with Acacia woodlots. Detailed analyses of habitat requirements for larva and/or adult B. brevicornis suggest that it lays its eggs on Acacia pennatula and A. macracantha (two newly recorded larval host-plants), that eggs were laid disproportionately on Acacia trees with long branches (χ2 = 17.7, P < 0.001) and that the probability of finding adult B. brevicornis between occupied and un-occupied Acacia woodlots increased with host-plant density (χ2 = 18.4, P < 0.001). The results of this study suggest that conservation recommendations for B. brevicornis must consider the condition of the Acacia habitat network, given that Acacia is mostly associated with human-managed grazing systems. Effective conservation will require the establishment of connected networks of patches where natural dynamics can produce new habitats, as well as the creation of new habitats within colonisation distance. This research provides a rare case study of conservation biology of a Neotropical insect, emphasising the importance of using ecological information to provide management recommendations.

Use of a new class of molecular marker for evolutionary or conservation studies may promise improved information, but it may also call for reassessment of analytical methods and empirical limitations. We used DNA microsatellites to study population structure in Rocky Mountain bighorn sheep (Ovis canadensis canadensis) and to test the ability of microsatellites to distinguish bighorn subspecies. Genetic differentiation between bighorn populations was dramatically greater than in comparable studies of brown bears and grey wolves, and these species differences are consistent with known differences in habitat use and dispersal. In bighorn, however, statistical limitations make it difficult to distinguish between moderately and highly divergent populations. As a result, only gene flow estimates greater than about one migrant per generation (OMPG) are informative about true population relatedness. In bears and wolves, apparent differentiation is so low that migration estimates are greater than OMPG continent-wide, but factors other than high gene flow may contribute to these patterns. Despite analytical difficulties at large geographical scales and large genetic divergences, microsatellite data assist management by characterizing historical rates and patterns of dispersal on smaller scales, and by detecting population bottlenecks and regions of particularly high or low historical gene flow.

Achieving maximum productivity in remnant populations of black rhinoceros is crucial to the persistence of this species. It was, therefore, investigated whether the black rhino population of Pilanesberg National Park had become regulated by resource limitation 22 years after introduction in 1979. Inter-calving intervals (which are not restricted to yearly time increments, due to asynchronous reproduction) decreased with an increase in rainfall, while the percentage of male calves born increased with increasing rainfall. The percentage of reproductive cows achieving maternal success increased with increasing density until 0.085 rhinos/km2, after which it decreased. This positive relationship at low densities is largely due to changes in the female age structure and the adult female/male ratio. The age at first calving tended to increase with increasing density, while mortality was not related to rainfall or density. It is concluded that the Pilanesberg black rhino population is showing the first signs of density dependence. It is proposed that black rhino conservators should monitor the percentage of cows achieving maternal success to detect early indications of density dependent resource limitation and use this as a criteria for decisions regarding metapopulation management.

The distribution and global habitat association of the North African houbara bustard (Chlamydotis undulata sensu stricto) were studied for the first time in a large semi-arid steppe-land region in eastern Morocco. The study area has been protected from hunting for 6 years, but was still under significant pressure from grazing activities. Houbara distribution was assessed using point count surveys conducted during the 2002 breeding season and compared to natural- and human-related predictors. The hierarchy and quantification of influences was evaluated using a discriminant function analysis. Micro-topography first drove houbara bustard distribution, since birds were usually found in open flat tracts allowing visibility over a long distance for the prevention of potential predator approaches, but also for breeding males to be seen by conspecifics. ‘Flooding surfaces’ presenting concealment possibilities, as well as readily available food resources, were secondly sought. Proximity to wells was a surrogate to human presence and pastoral activity influences and appeared to affect houbara bustard distribution. The weight of human disturbance on houbara distribution is highlighted and it is recommended that this should be considered in conservation plans.

Conservation and ecological monitoring programmes often estimate animal densities over time, but in wooded and forested areas practical techniques are still poorly developed. Here I have examined five simple methods of deriving densities of large and medium-sized mammals using line transects driven through miombo woodland habitat in Africa. These methods calculated area by dividing the number of individuals seen by (i) an average of each species' sighting distances, (ii) a fixed 200 m belt width, (iii) the area visible from the centre of the transect, (iv) visible area weighted by species' vegetation preferences, and (v) by dividing the number of groups seen by area visible from the transect. Individual-based methods produced quite divergent estimates of species' densities and overall biomass with belt transects giving the lowest values. The group method and corresponding individual-based method gave similar values, however. Most of these calculations yielded considerably higher density estimates than aerial surveys conducted in the same area over a similar time period. Sightings of species were not distributed evenly across vegetation types although the majority of mammal species were observed more often in open habitat. These findings indicate that ground-based conservation monitoring programmes should set transects through several vegetation types, restrict comparisons to those studies that use the same methodology, and refrain from comparing ground and aerial surveys.

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.

Large carnivores are key visitor attractions in protected areas, but are difficult to see. Thus, supplementary feeding is sometimes used to attract them to viewing sites. Such intervention is contentious but its effects have rarely been examined. This paper analyses a case study of supplementary feeding in Komodo National Park, Indonesia. Using data from daily and annual Komodo dragon censuses, feeding records and financial accounts, the effects of feeding and its cessation on dragon numbers, tourist viewing opportunities and local community benefits were examined. Regular feeding caused dragon numbers to increase at the feeding site, but not year-round. Cessation of feeding caused numbers to decline again to natural levels. However, tourists were less likely to see dragons at the feeding site after cessation, and local community revenues declined with the loss of a market for goats. Solutions lie in finding less intrusive means for tourists to view dragons, and enabling local people to become involved in tourism through training, recruitment and the development of alternative markets.

The Cape Sable seaside sparrow is a Federally listed endangered species endemic to south Florida's Everglades. It nests near the ground in seasonally dry prairies. Consequently, the timing and depth of seasonal water flows determine its fate. With water management plans the central focus of Everglades' restoration schemes, the demography of this bird becomes central to hydrologic planning. In order to understand how its demography influences restoration options, we calculated survivorship, fecundity and dispersal within three of the sparrow's six populations. Nearly 40% of adult sparrows die from year to year. Sparrows can produce up to four broods per breeding season, and typically produce two (March to August). Females lay an average of three eggs per nest, two of which usually hatch. The success of these nests varies among populations such that nests in population E are more than four times as likely to fledge young as nests within population A. Nest success within population B is 26% early in the breeding season, but drops to 9% after the onset of summer rains in early June. Nests are built 16 to 21 cm from the soil surface making them vulnerable to water depths that exceed these values. Based on observations of marked individuals, sparrows generally remain within a 1 km area centred on their breeding grounds. We have never observed immigration between populations. A simple demographic model demonstrates that breeding success and duration appear to constrain sparrow population growth more than other demographic parameters. Maintaining suitable breeding conditions restricts water management options to those that will restore hydrological conditions to their original patterns.

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

The wild water buffalo is highly endangered, with the few remaining populations already affected or likely to be increasingly affected by hybridization with domestic buffalo. The work described here was done to evaluate a genetic method to discriminate wild from mixed ancestry (hybrid) and domestic animals, and to identify with high probability those most likely to be purebred wild. Samples from 45 animals (phenotypically classified into three groups - ten wild, 28 domestic and seven hybrid) were genotyped for ten microsatellite loci. Although genetic distances among the three groups were small, an assignment test identified two of the ‘wild’ and seven of the ‘domestic’ as hybrids. However, sample sizes also are small, indicating the need for a conservative approach in the first instance in using these results. As more animals are genotyped, assignments will become more accurate, and a translocation programme to establish a second Nepalese wild population in a protected area could be undertaken.

The Cape Sable seaside-sparrow (Ammodramus maritimus mirabilis) has disappeared from its only known breeding areas episodically since its discovery early this century. Systematic surveys across its range in the southern Everglades find the sparrow's range to be fragmented into six subpopulations. The sparrow population decreased by 58% between 1992 and 1995, with the near extinction of the western half of the population and the temporary local extinction of some eastern populations. Other similar grassland sparrows have populations that vary considerably from year to year. Yet the decline in the western subpopulation and the local extinction of some of the peripheral populations cannot be explained by natural variability alone. Hurricane Andrew passed over several subpopulations prior to the particularly poor year of 1993. However, the geographical and temporal patterns of subpopulation decline are not consistent with what would be expected following a hurricane. Frequent fires prevent successful breeding as does flooding during the breeding season. Better management can prevent frequent fires and episodic flooding. However, the long-term survival of the sparrow depends on managing the unanticipated risks that attend its small, fragmented population.

The general problem of evaluating the potential success of mammalian reintroduction plans has been tackled by a case study illustrating a four-phase approach to finding and assessing potential sites for the reintroduction of European beavers, Castor fiber, to Scotland, combining the use of Geographic Information Systems (GIS), fieldwork and population modelling. Phase 1 used GIS to investigate the wider availability of habitat for beavers in Scotland, and predicted that there is the capacity to support in the order of 180 to 390 beaver families. Phase 2 involved the preliminary assessment of nine sites using brief field surveys. Phase 3 focused further on the three most suitable sites, where a thorough habitat survey was used as a basis for calculating carrying capacities of between three and five families. Finally, phase 4 used population modelling to assess the viability and likely spread of beavers following release at these three best sites. High, medium and low parameters were derived from the literature, and populations were predicted to persist and spread as long as at least the medium parameters were used. This exercise illustrates the power of combining field surveys and GIS-based population modelling as a tool for planning reintroductions in general, and as a foundation for planning the reintroduction of beavers in particular.