Effective seabird management strategies rely on accurate population estimates, with previous methods typically employing ground counts of a target species. However, difficult and often inaccessible breeding habitats are now able to be explored due to recent technological advancements in Unoccupied Aerial Vehicles (UAVs). This study tested a novel approach by combining high-resolution orthomosaics and 3D models to provide population estimates of the remote cliff-breeding Bounty Island shag (Leucocarbo ranfurlyi) on the sub-Antarctic Bounty Islands in November 2022. Our results report 573 breeding pairs, estimating a total population of approximately 1733 birds, breeding on 13 of the 14 main islands. Given the topographical constraints of surveying the islands by boat, the most comparable assessment in 1978 shows a similar count of breeding pairs, proposing the Bounty Island shag population is stable. However, long-term monitoring and additional research surrounding foraging strategies is crucial for developing conservation efforts for one of the rarest and spatially restricted shag species in the world. Our study demonstrates a reproducible method for estimating elusive wildlife populations that can be used across species with wider applications.

The post Accurate abundance estimation of cliff-breeding Bounty Island shags using drone-based 2D and 3D photogrammetry first appeared on Avian Conservation and Ecology.

有效的海鸟管理策略依赖于准确的种群估计，以前的方法通常采用目标物种的地面计数。然而，由于无人飞行器（UAV）的最新技术进步，现在可以探索困难且通常难以进入的繁殖栖息地。这项研究测试了一种新颖的方法，通过结合高分辨率正射镶嵌和 3D 模型来提供偏远悬崖繁殖的邦蒂岛鸬鹬 ( Leucocarbo ranfurlyi)的种群估计）于 2022 年 11 月在亚南极邦蒂群岛上进行。我们的结果报告了 573 个繁殖对，估计总种群约为 1733 只鸟类，在 14 个主要岛屿中的 13 个岛屿上繁殖。考虑到乘船调查岛屿的地形限制，1978 年最具可比性的评估显示繁殖对的数量相似，表明邦蒂岛长毛种群是稳定的。然而，围绕觅食策略的长期监测和额外研究对于为世界上最稀有且空间有限的鲂物种之一开展保护工作至关重要。我们的研究展示了一种可重复的方法来估计难以捉摸的野生动物种群，该方法可以跨物种使用并具有更广泛的应用。

使用基于无人机的 2D 和 3D 摄影测量对悬崖繁殖的邦蒂岛鸬鹬进行准确丰度估计的文章首次发表在《鸟类保护与生态学》上。