Estimating long-term trends in abundance and survival for nesting flatback turtles in Kakadu National Park, Australia

Endangered species research

Rachel A. Groom^1¹  Milani Chaloupka^3²  Anthony D. Griffiths^1,2³ 

[1] Department of Environment and Natural Resources, PO Box 496, Palmerston, Northern Territory 0831, Australia^1;Ecological Modelling Services Pty Ltd and University of Queensland, PO Box 6150, St Lucia, Queensland 4067, Australia^3;Research Institute for Environment and Livelihoods, Charles Darwin University, Casuarina, Northern Territory 0909, Australia^2

关键词: Endemic;    Capture-mark-recapture;    World Heritage Area;    Recapture probability;   

DOI  :  10.3354/esr00795

学科分类：动物科学

来源: Inter-Research

【 摘 要 】

Flatback turtles Natator depressus are endemic to Australia and Papua New Guinea’s tropical oceans and, although the species has an extensive distribution around northern Australia, there are few published long-term abundance trends of nesting populations. We conducted a long-term capture-mark-recapture program on nesting flatback turtles on Field Island in Kakadu National Park, a World Heritage Area that is jointly managed by Aboriginal landowners and the Australian Government, from 2002 to 2013 for between 12 and 20 monitoring days per year. We used a Cormack-Jolly-Seber (CJS) model that accounted for transience and recapture heterogeneity to estimate apparent survival and recapture probability, and estimated abundance using a Horvitz-Thompson type estimator. A total of 257 flatback turtles attempted nesting during that period, averaging 3.68 ± 0.28 (mean ± SE) nesting attempts per night of monitoring. Annual apparent survival of nesting flatback turtles was 0.97 (95% CI = 0.94 to 0.98) and increased relative to body size. Recapture probability averaged 0.38 (95% CI = 0.34 to 0.42) and was influenced by inter-annual climatic variability. The size of the Field Island nesting flatback turtle population ranged from 97 (95% CI = 87 to 106) to 183 (95% CI = 165 to 200) and there was a non-significant trend over 12 yr of monitoring. Understanding long-term population trends of nesting marine turtles is fundamental for management and recovery of these at-risk species.

【 授权许可】

Unknown