In the early 1900s, the wolf (Canis lupus) was extirpated from France and Switzerland. There is growing evidence that the species is presently recolonizing these countries in the western Alps. By sequencing the mitochondrial DNA (mtDNA) control region of various samples mainly collected in the field (scats, hairs, regurgitates, blood or tissue; n = 292), we could (1) develop a non-invasive method enabling the unambiguous attribution of these samples to wolf, fox (Vulpes vulpes) or dog (Canis familiaris), among others; (2) demonstrate that Italian, French and Swiss wolves share the same mtDNA haplotype, a haplotype that has never been found in any other wolf population world-wide. Combined together, field and genetic data collected over 10 years corroborate the scenario of a natural expansion of wolves from the Italian source population. Furthermore, such a genetic approach is of conservation significance, since it has important consequences for management decisions. This first long-term report using non-invasive sampling demonstrates that long-distance dispersers are common, supporting the hypothesis that individuals may often attempt to colonize far from their native pack, even in the absence of suitable corridors across habitats characterized by intense human activities.

Using published IUCN red-lists for the threatened bird species of Indonesia (Stattersfield & Capper, 2000), we document that the species at risk in Indonesia are not a taxonomically random sample, consistent with patterns seen at the global scale (Purvis et al., 2000). This implies that a greater than random proportion of Indonesia's and the world's (through the loss of endemics) phylogenetic diversity (PD) is at risk (Von Euler, 2001). Using cytochrome b (Johns & Avise, 1998) and a distance-based taxonomy, we attempt to quantify this projected loss of PD in millions of years and conclude with a brief discussion of the conservation implications for Indonesia, and of the use of ‘evolutionary heritage’ as a measure for conservation at the geopolitical level.

We tested the association between host genetic diversity and resistance to a novel pathogen using controlled experiments to compare bacterially induced mortality among four populations of the endangered Gila topminnow (Poeciliopsis occidentalis) with different levels of genetic diversity, and between nine lines of inbred topminnows and their respective (non-inbred) source populations. We exposed fish in treatment groups to salinity shock and high concentrations of the bacterium Listonella (Vibrio) anguillarum, a causative agent of vibriosis in fish. Mortality associated with vibriosis (mortality) 1 to 6 days post-exposure differed among the populations, and between inbred and non-inbred samples. However, mortality was not associated with expected heterozygosity based on microsatellite loci diversity, nor was it associated with expected or observed heterozygosity at a major histocompatibility complex (MHC) class II locus. Neither was mortality related to the presence or absence of specific MHC alleles. Additionally, the effect of severe inbreeding was to reduce mortality in the inbred fish relative to the non-inbred controls in every population. Taken in the context of other studies, we conclude that effects of genetic diversity may be context- and locus-specific, environmental stress may be an important determinant of host immunity, and genetic diversity should be used cautiously to predict the potential response of a population to a specific environmental challenge.

The red-crested pochard (Netta rufina), a Eurasian diving duck, has seen its numbers declining and has received strong conservation concern. Data on population size and rate of decline are required to establish management plans, none of which is available for this species. Here we present the first population size estimate taking into account detection probability and habitat use in the Camargue, southern France. A non-random sample of 33 lakes was used to estimate detection probability from point-counts. Detectability was low, with only 57.5% of individual broods detected. A random sample of 37 lakes was then used to estimate brood densities. Adjusted densities (taking into account detection probability) were 0.1106 broods per ha of reedbed. Adjusted densities were extrapolated to the entire surface area of reedbeds in the Camargue estimated from a GIS to obtain abundance estimates of the brood population. A minimum estimate of 559 breeding pairs was obtained (95% confidence interval: 436-855). This estimate is much higher than previous ones (80-100 pairs for the Camargue, 250 pairs for France), and indicates strong underestimation of the population size when not taking into account detectability. Our results suggest that the red-crested pochard may require a reassessment of its conservation status for France and Europe. They further suggest that taking detection probability into account in population estimates of other cryptic species, and notably those of conservation concern, may help clarify their conservation status and may even affect the setting of conservation priorities.