Commonwealth Scientific and Industrial Research Organisation, Data61, Brisbane, QLD, 4072, Australia.
Commonwealth Scientific and Industrial Research Organisation, Data61, Hobart, TAS, 7000, Australia.
Sci Rep. 2023 Aug 2;13(1):12512. doi: 10.1038/s41598-023-38639-z.
Reliable information on population size is fundamental to the management of threatened species. For wild species, mark-recapture methods are a cornerstone of abundance estimation. Here, we show the first application of the close-kin mark-recapture (CKMR) method to a terrestrial species of high conservation value; the Christmas Island flying-fox (CIFF). The CIFF is the island's last remaining native terrestrial mammal and was recently listed as critically endangered. CKMR is a powerful tool for estimating the demographic parameters central to CIFF management and circumvents the complications arising from the species' cryptic nature, mobility, and difficult-to-survey habitat. To this end, we used genetic data from 450 CIFFs captured between 2015 and 2019 to detect kin pairs. We implemented a novel CKMR model that estimates sex-specific abundance, trend, and mortality and accommodates observations from the kin-pair distribution of male reproductive skew and mate persistence. CKMR estimated CIFF total adult female abundance to be approximately 2050 individuals (95% CI (950, 4300)). We showed that on average only 23% of the adult male population contributed to annual reproduction and strong evidence for between-year mate fidelity, an observation not previously quantified for a Pteropus species in the wild. Critically, our population estimates provide the most robust understanding of the status of this critically endangered population, informing immediate and future conservation initiatives.
有关种群规模的可靠信息是受威胁物种管理的基础。对于野生动物来说，标记重捕法是估计数量的基石。在这里，我们首次将近亲标记重捕（CKMR）方法应用于一种具有高保护价值的陆地物种；圣诞岛飞狐（CIFF）。CIFF 是该岛仅剩的本土陆地哺乳动物，最近被列为极危物种。CKMR 是一种强大的工具，可用于估计对 CIFF 管理至关重要的人口参数，并规避了该物种的隐蔽性、移动性和难以调查的栖息地所带来的复杂问题。为此，我们使用了 2015 年至 2019 年间捕获的 450 只 CIFF 的遗传数据来检测亲缘对。我们实施了一种新的 CKMR 模型，该模型估计了雌雄个体的数量、趋势和死亡率，并考虑了雄性生殖偏斜和配偶持久性的亲缘对分布的观测结果。CKMR 估计 CIFF 成年雌性总数约为 2050 只（95%置信区间（950，4300））。我们表明，平均只有 23%的成年雄性种群参与了年度繁殖，并且有很强的证据表明存在年度间的配偶忠诚度，这是以前在野外的 Pteropus 物种中没有量化过的观察结果。至关重要的是，我们的人口估计提供了对这一极危种群状况的最可靠了解，为当前和未来的保护计划提供了信息。
