Disease may play an important role in the decline or extinction of small, isolated animal populations. Disease also has thwarted attempts to reintroduce some endangered captive-bred species. Despite this, the impacts of disease rarely have been considered in the planning and design of reintroduction programmes. A remnant wild population could be decimated by a disease cointroduced with reintroduced animals. Alternatively, diseases that are endemic in wild animal populations could be fatal for those immunologically naive individuals that are reintroduced. We contend that the planning of reintroduction programmes should include an examination of the potential impacts of disease on extant populations and on animals targeted for release. A number of steps are outlined to reduce disease risk and to minimise the probability of failure of reintroductions because of disease.

Although fire is a major form of natural disturbance worldwide, both fire-derived landscape context effects and the impacts of fire severity are poorly known for many species. To address this knowledge gap, we quantified the response of Australian arboreal marsupials to: (1) the spatial effects of fire, (2) fire severity, and (3) fire impacts on the availability of critical nesting resources-hollow-bearing trees. We identified substantial differences among species in response to fire severity and landscape-scale fire. The Sugar Glider (Petaurus breviceps) and the endangered Leadbeater's Possum (Gymnobelideus leadbeateri) were extremely rare on burned sites irrespective of fire severity. In addition, these two species declined with the amount of burned forest in the surrounding landscape even when their habitat remained unburnt. The Mountain Brushtail Possum (Trichosurus cunninghami) and the Greater Glider (Petauroides volans) both occurred on burned and unburned sites. The Greater Glider responded negatively to fire severity at the site level and also negatively to the amount of forest burned in the surrounding landscape. The abundance of the Mountain Brushtail Possum was lowest on sites subject to moderate severity fire. On unburned sites, the presence and abundance of virtually all species was characterised by a common positive response to the availability of nesting resources in hollow-bearing trees. Our findings underscore the importance of management practices to better protect species that decline after fire. These include conserving areas of unburned forest, particularly those with hollow-bearing trees which are critical nest sites for arboreal 4 marsupials. These recommendations are currently the opposite of existing management practices. Highlights • The endangered Leadbeater's Possum was virtually eliminated by fire of any severity. • Leadbeater's Possum declined with increasing area of burnt forest in the landscape, even when its immediate habitat remained unburnt. • All arboreal marsupial species were positively associated with hollow-bearing trees. • Protecting unburnt forest with tree-hollows is now critically important.

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