Bino Gilad, Grant Tom R, Kingsford Richard T
Centre for Ecosystem Science, School of Biological, Earth &Environmental Sciences, University of New South Wales, Sydney 2052 NSW, Australia.
Sci Rep. 2015 Nov 5;5:16073. doi: 10.1038/srep16073.
Knowledge of the life-history and population dynamics of Australia's iconic and evolutionarily distinct platypus (Ornithorhynchus anatinus) remains poor. We marked-recaptured 812 unique platypuses (total 1,622 captures), over four decades (1973-2014) in the Shoalhaven River, Australia. Strong sex-age differences were observed in life-history, including morphology and longevity. Apparent survival of adult females (Φ = 0.76) were higher than adult males (Φ = 0.57), as in juveniles: females Φ = 0.27, males Φ = 0.13. Females were highly likely to remain in the same pool (adult: P = 0.85, juvenile: P = 0.88), while residency rates were lower for males (adult: P = 0.74, juvenile: P = 0.46). We combined survival, movement and life-histories to develop population viability models and test the impact of a range of life-history parameters. While using estimated apparent survival produced unviable populations (mean population growth rate r = -0.23, extinction within 20 years), considering residency rates to adjust survival estimates, indicated more stable populations (r = 0.004, p = 0.04 of 100-year extinction). Further sensitivity analyses highlighted adult female survival and overall success of dispersal as most affecting viability. Findings provide robust life-history and viability estimates for a difficult study species. These could support developing large-scale population dynamics models required to underpin a much needed national risk assessment for the platypus, already declining in parts of its current distribution.
对于澳大利亚标志性且在进化上独特的鸭嘴兽（Ornithorhynchus anatinus）的生活史和种群动态，我们所知甚少。在四十年间（1973 - 2014年），我们在澳大利亚的肖尔黑文河对812只独特的鸭嘴兽进行了标记重捕（总计1622次捕获）。在生活史方面，包括形态和寿命，观察到了明显的性别 - 年龄差异。成年雌性的表观存活率（Φ = 0.76）高于成年雄性（Φ = 0.57），幼体情况也是如此：雌性Φ = 0.27，雄性Φ = 0.13。雌性极有可能留在同一个水塘（成年：P = 0.85，幼体：P = 0.88），而雄性的居留率较低（成年：P = 0.74，幼体：P = 0.46）。我们结合存活率、活动情况和生活史来建立种群生存力模型，并测试一系列生活史参数的影响。虽然使用估计的表观存活率得出的种群不可行（平均种群增长率r = -0.23，20年内灭绝），但考虑居留率来调整存活率估计值时，显示种群更稳定（r = 0.004，100年灭绝概率p = 0.04）。进一步的敏感性分析突出了成年雌性存活率和扩散的总体成功率对生存力影响最大。研究结果为这个难以研究的物种提供了可靠的生活史和生存力估计。这些结果有助于建立大规模的种群动态模型，这是对鸭嘴兽进行急需的全国性风险评估所必需的，鸭嘴兽在其当前分布的部分地区数量已经在下降。
