Activity Patterns of Free-Ranging Koalas (Phascolarctos cinereus) Revealed by Accelerometry

Michelle A Ryan,Desley A Whisson,John P Y Arnould,Greg J Holland,Brock Fenton

doi:10.1371/journal.pone.0080366

Abstract

An understanding of koala activity patterns is important for measuring the behavioral response of this species to environmental change, but to date has been limited by the logistical challenges of traditional field methodologies. We addressed this knowledge gap by using tri-axial accelerometer data loggers attached to VHF radio collars to examine activity patterns of adult male and female koalas in a high-density population at Cape Otway, Victoria, Australia. Data were obtained from 27 adult koalas over two 7-d periods during the breeding season: 12 in the early-breeding season in November 2010, and 15 in the late-breeding season in January 2011. Multiple 15 minute observation blocks on each animal were used for validation of activity patterns determined from the accelerometer data loggers. Accelerometry was effective in distinguishing between inactive (sleeping, resting) and active (grooming, feeding and moving) behaviors. Koalas were more active during the early-breeding season with a higher index of movement (overall dynamic body acceleration [ODBA]) for both males and females. Koalas showed a distinct temporal pattern of behavior, with most activity occurring from mid-afternoon to early morning. Accelerometry has potential for examining fine-scale behavior of a wide range of arboreal and terrestrial species.

Highlights

An understanding of a species’ activity patterns is important for its conservation
Activity patterns are poorly understood for many species due to the limitations of traditional field methodologies
This study was approved by the Deakin University Animal Ethics Committee (A31-2010) and conducted under permit (10005379) by the Victorian Department of Sustainability and Environment

Summary

Introduction

An understanding of a species’ activity patterns is important for its conservation. More time may be spent in foraging where there is low availability of food resources [4], or activity may be restricted to the coolest times of the day where climates are warmer (e.g., [5]). Activity patterns are poorly understood for many species due to the limitations of traditional field methodologies. The low nutritive value and high fibre content of Eucalyptus foliage, together with the cost of detoxifying secondary plant compounds, interact to limit available energy for the species [7,8,9]. It is important to understand how koalas apportion time to different behaviors such as feeding and resting, and the factors influencing their activity patterns

Objectives

Methods

Results

Conclusion