A population and habitat viability analysis (PHVA) was carried out for the Malagasy giant jumping rat (Hypogeomys antimena), one of the key species of the highly threatened dry deciduous forests on the western coast of Madagascar. The occurrence of H. antimena is now confined to 200 km2 of fragmented but relatively undisturbed forest remnants, divided in northern and southern subpopulations. Since 1985 the habitat has declined by about 52% (1985: 42,000 ha; 2000: 20,000 ha). The annual rate of habitat decline increased from 3.9% between 1985 and 1995 to 4.4% between 1995 and 2000. Within a study area (Kirindy Forest/CFPF) in the southern subpopulation, the Hypogeomys population collapsed during the decade 1990-2000, as well as over its remaining range. An ongoing population decline within the next 100 years is predicted even if further habitat decline can be stopped within the next 5 years and no additional mortality by roaming dogs is considered. Thereby, the outcomes of two different individual-based simulation approaches, one that was explicitly written to reflect Hypogeomys life history and VORTEX, one of the most common software packages used for this purpose, were compared. The results of the Hypogeomys model were more pessimistic, but were within the range of predictions of the VORTEX model which calculated larger standard deviations of the mean values. In both subpopulations, a slight increase in the mortality caused by roaming dogs resulted in a predicted decline to an average population size of maximal 170 individuals within 100 years with a high risk of extinction. However, the simulations indicated that the most important factor is reduction in habitat. If the actual annual rate of habitat lost continues, the extinction of the both subpopulations and therefore the entire species is predicted within 24 years.

There is considerable interest in the use of assisted breeding techniques as a component of conservation programmes for a variety of macropods threatened with extinction. While cross-fostering is being conducted in some programmes in captivity, little is known about the best techniques for carrying this procedure out from wild populations. In this study we compare the success of various procedures for isolating small tammar wallaby (Macropus eugenii) and brush-tailed rock wallaby (Petrogale penicillata) pouch young (0.4 g–410 g) for short periods (6 hours) as a first step towards establishing a methodology for recruiting endangered macropod pouch young directly from the wild for foster-rearing in captivity. Pouch temperature and humidity were determined. Pouch young from females in experimental groups were weighed, measured and then isolated, at 30°C, 27°C or 23°C, and 100% humidity. After isolation the weight of pouch young maintained at 30°C and 27°C had declined significantly (2–17% of body weight), whereas those held at 23°C and 100% humidity lost less than 0.5% of body weight. All young were reattached to the active teat of their mother following pouch isolation and their survival and growth monitored. Pouch young from the control group and those isolated at 23°C and 100% humidity survived and grew at normal rates. Only the largest pouch young maintained in isolation at either 30°C or 27°C survived to day 7 following reattachment. Data indicated that the proportion of weight lost by pouch young as a result of isolation decreased with increasing size and age of the pouch young. These trials indicate that it would be possible to harvest very small macropod pouch young from a species in the wild with a very high probability that they would survive short-term isolation from the pouch and reattachment to the teat. The use of this procedure in combination with cross-fostering techniques will allow small pouch young from threatened macropod species to be recruited directly from the wild into captivity, for captive breeding or to improve genetic diversity in captive colonies. It should also act to reactivate diapause embryos in these animals and hence may accelerate breeding in wild-based mothers.

The Montagu's harrier (Circus pygargus) is a ground-nesting raptor that breeds mainly in cereal crops in western Europe. We evaluate how the use of agricultural habitats may affect population sustainability in this species, based on simulation analyses, and explore how conservation measures could be optimized. Probability of extinction increased with decreasing harrier productivity, and this trend was accentuated when the carrying capacity (maximum number of breeding pairs) decreased. Harrier productivity in agricultural habitats is strongly affected by harvesting activities. An average of 60% of nestlings in agricultural areas of France and the Iberian Peninsula would perish in the absence of conservation measures. These losses would make populations unsustainable, if no immigration occurred. Simulation analyses showed that connectivity between populations through natal dispersal could allow persistence of threatened populations even in the absence of conservation measures. The probability of extinction of four hypothetical populations connected through natal dispersal would be lowest if one of those populations were fully protected (or fully productive), even if the other ones were unprotected. Montagu's harriers are semi-colonial, and populations could be considered as a compound of subpopulations (the colonies). Additionally, Montagu's harriers bred more frequently in areas where food abundance was high, and where the number of fledglings produced in the previous reproductive attempt was high. These factors could be used to develop sustainable and efficient conservation plans, identifying and protecting the most productive and stable colonies in agricultural areas, and further exploring experimentally factors that are likely to attract and maintain harriers in protected areas.

Cheetahs (Acinonyx jubatus) held ex situ can provide an important resource for obtaining new biological information that usually cannot be gleaned from free-living individuals. However, consistent captive propagation of the cheetah, a prerequisite for establishing a self-sustaining population, has not been accomplished so far. This study examined the effect of a husbandry regimen commonly used in ex situ facilities on female cheetahs. Although generally solitary in the wild, zoos frequently house cheetahs in pairs or groups. Using non-invasive hormone monitoring and quantitative behavioural observations, we studied the impact of such enforced social conditions on behaviour and ovarian/adrenal activity. Eight female cheetahs were evaluated for two consecutive 6-month periods, first while maintained in pairs and then as individuals. Subsequently four females were regrouped into two new pairs and monitored for another 6 months. Females in five of six pairings demonstrated prolonged anoestrus and displayed agonistic behaviours. After pair separation all females rapidly resumed oestrous cyclicity. Females in the sixth pair continued cycling throughout the year while consistently displaying affiliative grooming and no agonistic behaviours. Faecal corticoid patterns varied significantly among individuals, but appeared unrelated to behavioural or ovarian hormone patterns. Thus, data appear to indicate that same-sex pair-maintenance of behaviourally incompatible female cheetahs may lead to suppressed ovarian cyclicity. This suppression appears linked to agonistic behaviours but not to any particular adrenal hormone excretion pattern. Results clearly demonstrate the value of applying knowledge about in situ social behaviour to ex situ management practices. Conversely, however, non-invasive hormone monitoring conducted ex situ may help us to identify physiological phenomena of potential relevance for future in situ studies.

Heaviside's dolphin, Cephalorhynchus heavisidii, is endemic to coastal waters of the western seaboard of South Africa and Namibia. The inshore habitat of the species places it at risk from commercial fishing operations and has led to concerns that the depletion of regional populations may result in loss of locally adapted genetic variation. To determine the geographic population structure of the Heaviside's dolphin, we obtained control region sequence (HVR1) from 17 specimens collected along the South African west coast and 18 animals taken along the Namibian coast. We identified 17 unique haplotypes within these 35 specimens which were aligned to 18 HVR1 sequences available from 40 specimens deposited in Genbank. A total of 20 maternal haplotypes was detected in the combined sample of 75 animals, of which ten were singletons. Neighbour joining and parsimony methods showed an absence of correspondence between group structure and geographic locality. Analysis of molecular variance (AMOVA) showed that almost all of the genetic variation is attributable to variation within geographic regions. This low level of differentiation between South Africa and Namibia is further underscored by an extremely low ϕST value suggestive of genetic homogeneity within the species. However, we caution that the failure to detect unambiguous population structure genetically does not necessarily mean that the population should be considered one panmictic unit for management purposes. Our genetic results should not be viewed in isolation but be considered in combination with information from nuclear markers, morphometrics, pollutants and tagging studies.

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.

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.

Australian mammals have one of the world's worst records of recent extinctions. A number of studies have demonstrated that red foxes (Vulpes vulpes) have a profound effect on the population biology of some species. However, not all species exposed to fox predation have declined. We studied the antipredator behaviour of a species that has not declined - the red-necked pademelon (Thylogale thetis), and contrasted it with previous studies on a species that has declined - the tammar wallaby (Macropus eugenii), to try to understand behavioural factors associated with survival. We focused on two antipredator behaviours: predator recognition and the way in which antipredator vigilance is influenced by the presence of conspecifics. We found that predator-naïve pademelons responded to the sight of certain predators, suggesting that they had some degree of innate recognition ability. However, pademelons responded similarly to a broad range of acoustic stimuli, including dingo howls, wedge-tailed eagle calls, foot-thumps - a predator-elicited sound - and a control sound, suggesting that they did not specifically recognize predator vocalizations. Unlike a number of other macropodid marsupials, including tammars, pademelons did not modify time allocated to antipredator vigilance as group size increased. Taken together, these results suggest that red-necked pademelons independently assessed and managed their predation risk whereas tammars relied more on conspecifics to assess and manage risk. We suggest that these factors may have been important determinants of species survival. More generally, we suggest that a fundamental understanding of antipredator behaviour can enlighten conservation efforts.

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.

In recent decades, the abundance of otter, Lutra lutra, decreased in many European countries. This study aimed at determining if varying occurrence of otters is related to land features and if this occurs at many spatial scales. Values of landscape features were compared among three categories of otter occurrence, i.e. absent, sporadic and common, for 25 European countries, for 19 regions and 22-40 departments in France. At all scales, significantly higher human and road densities were detected in areas where otters are absent, which illustrates the pervasive impact of human presence on otter population fragmentation. Moreover, particular natural features (‘percentage other use’ defined as non-agricultural and non-forested) may also limit otter populations at the scale of Europe. Our study failed to detect significant differences in landscapes occupied by common or sporadic otter populations, probably owing to a limited sample size, or to the resilience of otters. The conservation of the European otter in Europe would benefit from an improved list of common large-scale land descriptors, the recognition of large gaps of naturally unsuitable habitats, and the development of international large-scale conservation studies to support existing regional otter conservation efforts.