Burrow-nesting seabirds constitute an important part of seabird diversity, yet accurate estimates of their abundance are largely lacking, limiting our understanding of their population dynamics and conservation status. We conducted a survey to estimate the number of South Georgia diving petrel (Pelecanoides georgicus) burrows during the 2013–14 breeding season on Ile de la Possession, Crozet archipelago, southern Indian Ocean. We used distance sampling and acoustic playback in order to estimate burrow densities in a priori-selected favourable nesting areas. A total of 855 burrows were detected. The mean altitude of burrows was 601.8 ± 69.4 m. The mean burrow detection distance was 1.77 ± 1.63 m. The burrow density was estimated at 15.649 burrows ha-1 (95% confidence interval (CI): 10.245–23.903) and the slope-corrected total favourable area was 2365.53 ha, which yielded an estimate 37 018 burrows (95% CI: 24 235–56 544). The playback response rate was 15.8 ± 1.3%, and 40.8 ± 1.7% of burrows were occupied or showed signs of occupation. Occupancy rates were low compared to those measured by systematic burrow inspection in other studies. Assuming that laying occurred in 80–93% of the estimated number of burrows, as estimated by previous studies, gives an estimate of 29 614 (95% CI: 19 388–45 235) to 34 426 (95% CI: 22 538–52 585) breeding pairs.

中文翻译：

---

对克罗泽群岛 Ile de la Possession 的南乔治亚潜水海燕 Pelecanoides georgicus 种群的估计

穴居海鸟是海鸟多样性的重要组成部分，但在很大程度上缺乏对其数量的准确估计，这限制了我们对其种群动态和保护状况的理解。我们进行了一项调查来估计南乔治亚潜水海燕的数量（鹈鹕) 在 2013-14 年繁殖季节在印度洋南部克罗泽群岛的 Ile de la Possession 挖洞。我们使用距离采样和声学回放来估计洞穴密度先验- 选择有利的筑巢区。共检测到 855 个洞穴。洞穴的平均高度为 601.8 ± 69.4 m。平均洞穴探测距离为 1.77 ± 1.63 m。洞穴密度估计为 15.649 洞穴公顷-1（95% 置信区间（CI）：10.245-23.903），斜率校正的总有利面积为 2365.53 公顷，估计有 37 018 个洞穴（95% CI：24 235-56 544）。回放响应率为15.8±1.3%，40.8±1.7%的洞穴被占用或出现占用迹象。与其他研究中通过系统洞穴检查测量的入住率相比，入住率较低。假设之前的研究估计的洞穴数量的 80-93% 发生了产卵，则估计为 29 614（95% CI：19 388-45 235）至 34 426（95% CI：22 538- 52 585) 繁殖对。