Seasonal and daily activity of non-native sambar deer in and around high-elevation peatlands, south-eastern Australia

Abstract

Context Of the six species of non-native deer present in Australia, the sambar deer is the largest and has been identified as a major threat to high-elevation peatlands in south-eastern Australia. However, little is known about sambar deer activity in high-elevation peatlands. Aims The aims of this study were to quantify sambar deer activity (including wallowing) seasonally and daily in response to biotic and abiotic variables, and how activity was impacted by ground-based shooting. Methods To estimate sambar deer activity, camera traps were continuously deployed for 4 years in two ~4300-ha areas in Alpine National Park, Victoria, south-eastern Australia. One area was subject to management operations using ground-based shooting to target deer and the other was not. Monthly activity of sambar deer was modelled using biotic (woody vegetation cover), abiotic (snow depth, aspect, slope, distance to water, road and peatland) and management (treatment versus non-treatment) covariates. Additional camera traps were deployed to monitor sambar deer activity at wallows. Key results Sambar deer activity decreased when snow depth increased (between July and September), and was highest in easterly and northerly aspects with dense woody vegetation close to high-elevation peatlands and roads. During our 4-year study, sambar deer activity decreased in the treatment area but increased in the non-treatment area. Sambar deer exhibited a crepuscular diel cycle, with greatest activity around sunset. Only male sambar deer were observed to wallow, with most wallowing occurring in the afternoon during October–June. Conclusions Sambar deer utilised high-elevation peatlands during October–June. Daily activity was crepuscular and was greatest in dense tree cover close to roads. Ground-based shooting reduced sambar deer activity in and around high-elevation peatlands. Implications Control operations targeting sambar deer at high elevations in south-eastern Australia should be conducted during October–June. Outside this period sambar deer appear to use lower-elevation habitats. The effectiveness of ground-based shooting could be improved by focusing this control action around sunset (when sambar deer are most active) and in places with dense vegetation close to roads and high-elevation peatlands.