Possums are a pest in New Zealand and knowledge of variations in their behaviour is important in developing effective and efficient control strategies. In this study, possums at two sites of similar habitat and density exhibited larger home-ranges and used more dens, compared to a third site of different habitat and higher density. This research suggests that control strategies should be adapted depending on habitat and density to account for variations in the behaviour of possums. Photograph by Belinda Whyte.

Genetic analysis provided evidence that released captive-bred hares had survived long enough and/or they had at least one reproductive cycle and, thus, transmitted their genomes. Alien strains of EBHSV are co-introduced with released captive-bred animals, possibly resulting in negative impacts on populations of Greek hares. Therefore, it is imperative to reinforce microbiological and genetic controls before further releases of captive-bred game species in the wild in Greece.

Animal density, despite being conceptually simple, it is one of the most difficult parameter to measure in the field. We compared density estimates of a lizard, Podarcis lilfordi derived by line transects with those from a simultaneous capture–recapture study in three islands of the Balearic archipelago (Spain). The two methods delivered similar results but have different pitfalls and advantages. Line-transects provided a fast and economic method, but density estimates changed over space and time. On the other hand capture-recapture techniques were time consuming, but estimates were similar over the sampling days and showed lower variances. Photograph by G. Tavecchia.

Changes in pest behaviour following pest control can undermine manager’s attempts to protect native ecosystems. A study of possum diet changes following pest control in New Zealand forests showed marked shifts in possum feeding patterns, with control survivors consuming more of their highly preferred, and often scarce, foods than before control. Shifts in pest diet following control will reduce the benefit of control for those resources more heavily selected after control, but conversely, will enhance the benefits to other resources. Photograph by Caroline Thomson.

Free-ranging wildlife impacts on water quality (particularly faecal contamination) is a poorly understood component of watershed management. We investigated Escherichia coli (E. coli, an indicator of faecal contamination) deposition by free-ranging mammals in Texas, USA, to provide detailed data about faecal contamination into watersheds. We determined that four species commonly found in North American watersheds (i.e. raccoons, Virginia opossums, white-tailed deer and wild pigs) contributed E. Coli, thus indicating the need to include these mammals in watershed models and management plans. Photograph by Israel Parker.

Tailoring pest management resources to habitats that support the highest pest numbers could be a cost-effective way of controlling brushtail possums in New Zealand and disrupting the cycle of tuberculosis. Models were developed, by cross-referencing possum captures against information on landform features and vegetation cover, to predict spatial possum distribution in the semi-arid South Island high country. Key predictors of relative possum abundance were identified that could enable pest managers to evaluate possum densities and thus target their control efforts. Photograph by Andrea Byrom.

Distribution, habitat preferences and responses to logging of an endangered yellow-bellied glider population were assessed using data collected in 1995 and a subset of these sites in 2010. Gliders preferred montane gum-dominated forest types and used mixed forest types in proportion to their availability. Occupancy was not related to logging and habitat was not restricted by elevation or confined to areas previously surveyed on State Forests. The listing of this endangered population appears inconsistent with relevant listing criteria and requires review. Photograph by Peter Kambouris.

The population dynamics of invasive species are often difficult to measure by trapping or observation, which can make it hard to evaluate the effectiveness of control programs. We used DNA analysis of fox hairs to non-invasively identify individual foxes in arid Western Australia and to detect both a significant reduction in fox density after control with 1080 poison, and a slower rate of post-control recruitment than is usually observed in mesic parts of Australia. These results imply that fox baiting programs in this arid region and elsewhere where recruits are limited may be carried out at low frequency to suppress fox density to a fraction of pre-control levels. Photograph by Neil Hamilton.

Oil spills cause significant detrimental impacts to shoreline species and habitats. Endangered New Zealand dotterels were pre-emptively captured as part of the response to the CV Rena oil spill. Intensive husbandry was required to convert the 60 birds to a captive diet, minimise trauma and manage foot problems, yet six deaths in captivity were solely due to respiratory aspergillosis. Captive management of shorebirds carries significant costs and risks, but should be considered in the emergency management of high-priority species. Photograph by Maritime New Zealand.