The Egyptian vulture (Neophron percnopterus) breeds in Sicily and, in 22 years of monitoring, has shown a decline followed by a slight recovery. We used Generalised Linear Models to predict: (1) the distribution range, (2) the habitat selection within the range, (3) the quality (i.e., occupation rate, breeding success) of breeding sites. Some 60% of Sicily proved to be unsuitable, being either too densely forested and without cliffs for nesting, or too densely populated, along with intensive agriculture. The models converged, indicating that the pairs select a precise upland habitat where low cliffs, distant from urban areas, are surrounded by arboreal crops and Mediterranean vegetation. The variables predicting the quality of a site are also related to human disturbance, including the distance from a road or the presence of heavy traffic. Natural restocking, in the last 3 years, is occurring in quiet sites and in proximity to extensive grazing land rich in sheep and goat herds. These results focused on short-term programmes for local management of the species aimed at protracting the natural restocking: namely, the activation of (1) a stable system of artificial feeding stations, (2) nest site protection with joint activities for increasing public awareness, (3) a reintroduction project, by hacking, of juveniles born in captivity in Italian and European breeding centres.

Estimating the risk of extinction or decline requires estimates of the variability in vital rates, such as survival and fecundity. This paper describes a method for estimating variance of survivals and fecundities from census data. The method involves calculating an estimate of the variance in survival and fecundity due to demographic stochasticity and subtracting this estimate from an estimate of total variance. The method is demonstrated by applying it to the data set on acorn woodpeckers by Stacey & Taper (1992), and tested in a series of simulations. The results show that the method can estimate the environmental variance with no bias. The main advantages of this method are its simplicity, its independence of the underlying distribution, and its applicability to estimating the variance of fecundity as well as of survival.

Conservation of tropical forests requires an understanding of the seasonal patterns of abundance and distribution of important seed dispersers. In the forests of Central Africa, three species of hornbills in the genus Ceratogymna (Aves: Bucerotidae) provide dispersal for over 50 species of trees and lianas, yet their ecology is poorly known. We present the first empirical evidence for resource tracking and large-scale movements by two of these species, which were previously considered resident. Hornbill numbers and fruit production were estimated over a one-year period in the Dja Reserve, Cameroon. Monthly abundances of C. atrata and C. cylindricus varied four- and 12-fold, respectively, and were predicted by community fruit availability as measured by fruitfall on a 4.3 km trail. In contrast, C. fistulator abundances varied little and were not related to fruit availability. Synchronous population fluctuations in sites 22 km distant were observed for atrata and cylindricus, but not for fistulator. Together, these results indicate that atrata and cylindricus populations track fruit resources via seasonal emigrations, while the fistulator population appears to be relatively sedentary. Comparisons of hornbill densities in primary and secondary forests suggest that they are important dispersers in both habitats, and will likely play larger roles in central African forest regeneration as more vulnerable seed dispersers are removed by hunting. If large seasonal movements of hornbills turn out to be a general phenomenon, effective management of central African forest reserves will require greater emphasis on reserve connectivity and on seasonal and spatial patterns of fruit production.

The abundance of foraging bats (Pipistrellus pipistrellus and Myotis daubentonii) and flying insects over two rivers in north-east Scotland (Dee and Ythan), differing eightfold in nitrate levels, were compared by paired samples over three periods in summer 1995, during each of which 10 nights' sampling was undertaken using ultrasonic detectors and insect suction traps. Thirteen out of the 18 pairwise comparisons of bat passes, insect numbers, biomass and diversity were not significantly different. The oligotrophic Dee supported higher numbers of bats than the eutrophic Ythan in June, but this was attributed to an effect of adverse weather conditions affecting the Ythan. In July and August–September, neither bat abundances nor the abundance of Chironomidae and Trichoptera, the main food of the bats, differed significantly between the two rivers, although the Ythan showed higher total insect biomass than the Dee. The Ythan also showed a much higher abundance of small Diptera, mainly Psychodidae and Cecidomyiidae, associated with elevated nitrogen levels in the intensively farmed river valley. Thus a small eutrophic river can support as many bats and as high an insect density as a large oligotrophic one.

Habitat loss and alteration is the leading cause of species' declines world-wide, therefore habitat restoration and protection is a prominent conservation strategy. Despite obvious connections between habitat and threatened or endangered species, conservationists have been hard pressed explicitly to link abundance or population health with habitat attributes. Given that habitat relationships with species are often characterized at a spatial scale that does not account for the functional relationships between habitat and populations, it is not surprising that the habitat-population conundrum persists. In order to explore the influence of spatial scale on the apparent relationship between habitat and populations, we examined the relationship between GIS-based habitat data and spring/summer chinook salmon (Oncorhynchus tshawytscha) redd (spawning nests built by females) densities in the Salmon River basin, Idaho, at two very different spatial scales: stream reach and watershed. Redd density was strongly correlated with climate, geology, wetlands and terrain. However, our stream-reach scale models provided poor predictive power compared with the watershed scale models. Based on these results, we conclude that our perception of which habitat attributes were important was clearly a function of our scale of observation, and that restoration efforts should focus on conditions at the watershed or landscape scale when attempting to do local or reach scale restoration projects.

Elephant social structure is matrilineal, with family units composed only of maternally related females and their juvenile offspring, while adult males are mostly solitary and seldom congregate into bachelor herds. In such a social structure, we expect females in the same family unit to have the same mitochondrial genome, which may or may not differ from that of individuals in other family units in the population. Such social structuring also results in the mating males and females having different allele frequencies at nuclear microsatellite loci. This is manifested as an excess of heterozygotes relative to the expected Hardy-Weinberg proportions, a phenomenon which maintains genetic variation within the population by minimizing inbreeding. We analyzed mitochondrial nucleotide sequences and allele frequencies at four microsatellite loci in nine family units of the African elephant (Loxodonta africana) in Queen Elizabeth National Park and found more than one distinct mitochondrial genotype in three of the family units and no significant excess heterozygosity at microsatellite loci in eight of the families. We interpreted these findings as an indication of a breakdown in social structure of this population caused by social stress due to factors like excessive poaching that has taken place in this national park over the last three decades. Ecological and management implications of these findings for elephant populations are discussed.

In Italy, pre-Alpine forests, once managed through coppice silviculture, are being converted to mature woodland, while land abandonment is causing woodland expansion and erosion of open habitats. Based on habitat-selection analyses, we predicted the impact of such changes on common buzzards (Buteo buteo), which depend on forested and open areas for nesting and foraging. Compared to availability, at a micro-scale buzzards selected nests higher above ground and on trees frequently covered by ivy. At the landscape-scale, buzzards avoided roads and conspecifics, while selecting rugged areas with high habitat heterogeneity, probably related to a varied food supply. Productivity was related to the availability of arid habitats, probably because of their richness in main prey species. Finally, population density was negatively related to the abundance of eagle owls (Bubo bubo), a potential predator of adults and nestlings, and positively related to the availability of woodland, a low predation-risk habitat rich in food and nest-sites. Therefore, buzzard settlement, density and productivity depended on the complex interplay of food availability, human persecution and predation risk. Thus, the current landscape changes would benefit buzzards by providing more nest-sites, but would be detrimental because of the lower productivity associated with the disappearance of dry open areas. Proposed conservation guidelines focus on conversion of coppice woodland to mature forests and active management of dry heath, a conservation sensitive habitat, through controlled burning.

A small blackish muntjac has been discovered in the west Quang Nam province of Vietnam. DNA sequencing of six individuals showed that this is a distinct species. A description is given. The new find is the third new ungulate species to be discovered in Vietnam in five years. The paper predicts that more species remain to be found in the Annamite mountain range and includes DNA analysis from two more undescribed species. The DNA analysis indicates that there has been a radiation of several related muntjac species in the Annamite mountains, also that the new truongson muntjac shows high intraspecific genetic diversity indicative of a large effective population size. The paper discusses the significance of these finds from an evolutionary and conservation viewpoint. The authors urge conservation authorities in the IndoChinese countries to devote special measures to protect this site of dynamic evolution which retains a combination of relict endemics (e.g. Pseudoryx) as well as on-going speciation.

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.

Nearshore oceanic archipelagos are natural laboratories that could provide valuable insight into the role of evolutionary processes such as founder effects and incipient speciation in biotic conservation. The Alexander Archipelago of Southeast Alaska is an example of such a complex, yet few biological investigations have been conducted. For the past 50 years, the region has experienced intense anthropogenic disturbances (particularly timber harvesting), causing habitat fragmentation and potential disruption of biotic communities. As part of a series of studies of mammals endemic to Southeast Alaska, we examined mitochondrial DNA sequences from 118 flying squirrels to investigate genetic diversity across Southeast Alaska. Mitochondrial sequence divergence corroborates the subspecific designation of the endemic Prince of Wales flying squirrel (Glaucomys sabrinus griseifrons). This island lineage exhibits severely reduced genetic variation and may be the result of an early Holocene founder event. Nearly all of the animals we examined on Prince of Wales Island and ten islands to the west had identical cytochrome b (52 of 53) and control region (21 of 21) sequences. In contrast, substantial polymorphism and little genetic structuring were found in comparable populations on the mainland of Southeast and Interior Alaska. Because flying squirrels in the Pacific Northwest are associated with old-growth forest, forest-use plans should aim to conserve this unique lineage of island squirrels.

Logging and poaching have dramatically reduced chimpanzee density and distribution in the Republic of Congo. Most chimpanzee translocations attempted in the past failed because a number of biological and non-biological factors can influence success. Biological considerations include knowledge of behaviour, disease, habitat requirements and genetics. We critically review genetic considerations in pre- and post-release phases of translocations and apply them to a welfare-based chimpanzee release project in the Republic of Congo which aimed to re-establish orphan chimpanzees in the wild with a native chimpanzee population. We analyze genetic diversity and relatedness in released animals and devise a genotyping strategy for monitoring of released individuals and their future offspring. Fifty-nine confiscated chimpanzees from different areas of the Republic of Congo were typed for 20 microsatellites using plucked hair as the DNA source. Genetic diversity was high, with an average expected heterozygosity of 81%, and three to 18 alleles per locus. Between 1996 and 1998, 19 individuals were released, and genetic analysis showed that these are unrelated (mean r ± jack-knifed SD = −0.014 ± 0.001). Using FST and population admixture analysis, we identified population structure in wild chimpanzees. For long-term genetic monitoring of released and native chimpanzees, we identified a set of six informative markers, which are easy to score using basic techniques.

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.

Synthetic products based on biodiversity information such as gap analysis depend critically on accurate models of species' geographic distributions that simultaneously minimize error in both overprediction and omission. We compared current gap methodologies, as exemplified by the distributional models used in the Maine Gap Analysis project, with an alternative approach, the geographic projections of ecological niche models developed using the Genetic Algorithm for Rule-Set Prediction (GARP). Point-occurrence data were used to develop GARP models based on the same environmental data layers as were used in the gap project, and independent occurrence data used to test both methods. Gap models performed better in avoiding omission error, but GARP better avoided errors of overprediction. Advantages of the point-based approach, and strategies for its incorporation into current gap efforts are discussed.

Mammalian record collection densities and bias attributable to observer survey preferences are assessed for the former Transvaal region of South Africa using a geographic information system (GIS). A method is presented which may be used to distinguish between highly biased and relatively unbiased sampling densities. Small mammal survey records within the region appear to have been collected relatively independently of the road and urban area infrastructure and are not biased towards nature reserves. Large mammal data on the other hand has mostly been collected within existing conservation areas. Although this latter data set would appear to be highly biased, it does accurately reflect the current distributions of larger mammalian taxa, which are presently almost entirely restricted to conservation areas.

The Ethiopian wolf (Canis simensis) is a very rare, endangered, endemic species surviving in isolated mountain pockets in the Ethiopian highlands, with nearly 50% of the global population living outside protected areas. In this paper we compare the ecology and behaviour of an Ethiopian wolf population living in Guassa, a communally managed area in the Central Highlands, with that of the Bale Mountains National Park in the Southern Highlands. Ethiopian wolves live at lower density in Guassa (0.2±0.05/km2) than in the Bale Mountains, but giant molerats (Tachyoryctes macrocephalus), the main prey for Ethiopian wolves in Bale Mountains, do not occur in the Central Highlands. Faecal analysis identified nine prey categories across wet and dry seasons common to both populations. In total, rodents accounted for 88% of prey volume in wolf diets. Home-range size was positively related to pack size (r2=0.85) and there was no difference in mean home-range sizes in both areas. In Guassa, however, wolves spent less time in the presence than in the absence of humans, but wolves spent similar amounts of time in the presence and absence of cattle. These findings suggest wolves can cope with, or adapt to, the presence of livestock and people in communally managed areas.

This study examines the population genetic structure of Asian elephants (Elephas maximus) across India, which harbours over half the world's population of this endangered species. Mitochondrial DNA control region sequences and allele frequencies at six nuclear DNA microsatellite markers obtained from the dung of free-ranging elephants reveal low mtDNA and typical microsatellite diversity. Both known divergent clades of mtDNA haplotypes in the Asian elephant are present in India, with southern and central India exhibiting exclusively the β clade of Fernando et al. (2000), northern India exhibiting exclusively the α clade and northeastern India exhibiting both, but predominantly the α clade. A nested clade analysis revealed isolation by distance as the principal mechanism responsible for the observed haplotype distributions within the α and β clades. Analyses of molecular variance and pairwise population FST tests based on both mitochondrial and microsatellite DNA suggest that northern-northeastern India, central India, Nilgiris (in southern India) and Anamalai-Periyar (in southern India) are four demographically autonomous population units and should be managed separately. In addition, evidence for female philopatry, male-mediated gene flow and two possible historical biogeographical barriers is described.

Among tourist activities in the Alps, winter sports have a prominent role because of the large scale of changes they cause at the habitat and landscape level. We have analysed whether ski resorts lead to significant threats to the avian diversity in the coniferous forests of the western Italian Alps, by comparing the bird communities of plots located in (1) the forest interior, (2) forest at the edge of ski-runs and (3) forest at the edge of pastures (the latter two are anthropogenic elements of forest fragmentation). Ski-runs produce a negative edge effect in the study forests: plots at their edges present lower bird species richness and Shannon diversity than those located in the forest interior or at the edges of pastures. In particular, birds typical of ecotone habitats seem to favour forest plots set at the edge of pastures. Ski-run-edges are linear landscape features that create high contrast edges; conversely, vegetation structure is more complex at the edge of pastures, attracting a rich and diverse avifauna. In the study area, pastures tend to be abandoned whereas winter sport resorts are increasing in extent. Accordingly, there is a need for coordinated management and cooperation between sport- and land-management agencies, in order to preserve native biodiversity while simultaneously managing land for sport activities.

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

We extend an earlier population viability analysis (PVA) of the Asian elephant (Elephas maximus) conducted by Sukumar & Santiapillai (1993) in order to examine how conclusions about viability can depend upon the time frame examined. We find that there is an approximately 200 year lag period before extinction events begin to occur in slowly declining populations of E. maximus. Therefore, examining population persistence over a 100 year time frame seriously underestimates the risk of population extinction over a longer, 1000 year period. These results are supported by the use of both a species-specific model of elephant demography, ELEPHANT, and a generic PVA package, VORTEX.

For populations with long generations, a 100 year time period will often not be sufficient to evaluate demographic processes leading to extinction. These results have important implications for how investigators conduct PVAs, and for the listing of endangered species by the World Conservation Union (IUCN).

Most species-specific conservation efforts require estimates of population size to establish priorities and to monitor management activities. Yet obtaining reliable estimates of animal populations is often difficult, especially given time and funding limitations experienced by many research programmes. Consequently, there is a great need for practical methods to provide indices of animal density. Ideally, accurate estimates of populations would be obtained through mark-recapture data collected from recognizable individuals over multiple censuses that cover the entire population range. Such data are rarely available, so conservation biologists have no alternative but to resort to analyses of less perfect data, ranging from permanent-point censuses from cameras through to transect data on sightings and spoor encounters. The importance of census and monitoring data makes the development, and validation, of new techniques a priority. Because we do not live in a perfect world, there is a need to develop methods that can give an estimate of population sizes. It would be naïve to assume that these will give hugely accurate estimates of population size, but these techniques can prove useful in identifying areas that are likely to benefit from conservation action.