The success of captive-breeding and release programmes is often compromised by predation of released individuals, which are naïve about predators. Pre-release behavioural preparation of release candidates in the form of anti-predator training has been attempted infrequently, usually using models of predators, but success was most often measured in terms of improved behavioural responses rather than survival to breeding age after release. Here we report that post-release survival of captive-reared houbara bustards (Chlamydotis [undulata] macqueenii) was improved through exposure to a live predator before release: a result with possible applications for a wide range of species currently the focus of reintroduction projects. We also show that rearing houbara with minimal human contact and training with a model of a predator had no effect on post-release survival. Moreover, neither pre-release behavioural responses to a model predator nor the degree of tonic immobility were predictors of post-release survival.

We sequenced part of the mitochondrial DNA control region of the extinct Arabian ostrich, Struthio camelus syriacus, to determine its phylogenetic relationship to the surviving subspecies, and to provide genetic information pertinent to the reintroduction of contemporary ostrich into Saudi Arabia. Parsimony, neighbour joining, maximum likelihood and a minimum spanning network all supported a close genetic association between the Arabian S. c. syriacus and the north African S. c. camelus. Furthermore, all our analyses suggest a recent common ancestry for the southern African S. c. australis and the east African S. c. massaicus. The Somali race, S. c. molybdophanes, was phylogenetically the most distinct of the ostrich taxa. Our data are supportive of a management decision to introduce S. c. camelus into areas once occupied by the extinct S. c. syriacus based predominantly on their geographic proximity and phenotypic features. Moreover, the presence of a shared lineage in these taxa indicates that gene flow between the two geographic forms may have been possible in the recent evolutionary past, probably along the Egyptian–Sinai–Israel passageway.

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.

Infectious disease is an emerging threat that conservationists are ill-equipped to manage. The threat is greatest for small populations, which can be driven to extinction by virulent pathogens; these are usually generalist pathogens that ‘spill over’ from other host species, often domestic animals. Recent attempts at disease control have taken a variety of forms, some directed at threatened hosts themselves, and others involving reservoir hosts. Thus far, few such attempts have demonstrated clear benefits of intervention, often because they were ‘crisis management’ tactics allowing no comparison with untreated controls. Design of future strategies is hampered by a lack of basic information concerning the pathogens that represent serious threats, their epidemiology in multiple-host systems, and the vaccination or treatment protocols likely to be most effective under field conditions. In general, vaccination and treatment will be most valuable in tiny populations facing very high extinction risks. However, interventions that are poorly planned or under-funded have the potential to do more harm than good. In larger populations, or over larger areas, intensive management may be inappropriate, unsustainable, or simply impractical. In these circumstances, managing population size, structure or contact between host species could offer promising alternatives to intervention.

In their native Australia, tammar (Macropus eugenii) and parma (M. parma) wallabies are allopatric and differ markedly in habitat use, social structure and degree of reproductive synchrony. They occur sympatrically only on Kawau Is., New Zealand, as a result of introductions last century. Reproductive data collected from wallabies on Kawau Is. in April 1996 show that M. eugenii maintains high reproductive synchrony while M. parma remains asynchronous. Both species show sexual dimorphism and differences in habitat use as seen in Australia. In addition M. parma is more solitary, and is frequently found in closed-canopy woodland, while M. eugenii tends to aggregate in open grassy clearings. Thus the species maintain broad reproductive and biological distinctions, despite enforced sympatry in a novel environment. Highly-resolving genetic (microsatellite) data reveal no evidence for hybridization. This is essential information given the known (M. eugenii) or likely (M. parma) high conservation value of New Zealand stocks. Kawau Is. is the only predator-free site with M. parma, a species whose persistence in Australia is threatened by fox predation. Finally, we use data on mitochondrial cytochrome b sequence divergence amongst several Macropus taxa to demonstrate close agreement with degree of reproductive isolation.

A field-validated metapopulation model of patch occupancy was used to examine the persistence of greater gliders (Petauroides volans) in patches of remnant native eucalypt forest in south-eastern Australia. The model was based on a system of eucalypt patches embedded within a plantation forest of exotic radiata pine (Pinus radiata) at Buccleuch State Forest, New South Wales. The probability of local extinction in occupied patches was a function of patch size. The probability of colonization of empty patches was a function of the size and proximity of occupied patches. The results of the simulations suggested that suitable habitat should occupy approximately 10% (or more) of the total landscape to ensure the persistence of greater gliders. Rates of patch occupancy were maximized when suitable habitat was clustered into larger patches. Patches <3 ha in area were predicted to be of limited value as habitat for greater gliders. The predictions of the model are consistent with the observed persistence of greater gliders in the eucalypt patch system. The system of unlogged eucalypt patches within the pine plantation is a useful model of a network of small to medium-sized conservation reserves. Principles of reserve design can have value even in somewhat degraded and highly modified landscapes. The results demonstrate that reserved patches of native forest embedded within intensively logged forest can have significant conservation value, with important implications for the design and establishment of new softwood plantations.

The Atlantic forests of South America hold a great concentration of biodiversity, but most of this habitat has been destroyed. We therefore expect many species to become extinct, and yet no bird extinctions have conclusively been recorded. There could be three explanations for this. First, birds may be able to adapt to deforested landscapes. Second, many species may have become extinct before they were known to science. Third, there may be a time-lag following deforestation before extinction occurs. We present the most complete list to date of the endemic birds of the Atlantic forests (124 forest-dependent species), and then use the species–area relationship to predict how many species we expect to become extinct through deforestation (51 species i.e. 41%). We also count how many Atlantic forest endemic birds are independently considered ‘threatened’ with ‘a high risk of extinction in the wild in the medium-term future’ (45 species i.e. 36%). We compare these totals and find that they are similar, suggesting that there is a time-lag between deforestation and extinction. We go on to test the robustness of this result by varying the parameters used to make our predictions. The only parameter that varies enough to substantially weaken predictions based on deforestation is the habitat classification of Atlantic ‘forest’ birds. If we include species that can survive in secondary and non-forest habitats then, unsurprisingly, we find that deforestation overestimates threat. Overall, not only does deforestation accurately predict threat to Atlantic forest endemic birds, but this result is robust enough to accommodate considerable variability within our data.

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.