Rendall Anthony R, Sutherland Duncan R, Cooke Raylene, White John
Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University Melbourne, Victoria, Australia.
Research Department, Phillip Island Nature Parks, Cowes, Victoria, Australia.
PLoS One. 2014 Mar 5;9(3):e86592. doi: 10.1371/journal.pone.0086592. eCollection 2014.
Invasive rodent species have established on 80% of the world's islands causing significant damage to island environments. Insular ecosystems support proportionally more biodiversity than comparative mainland areas, highlighting them as critical for global biodiversity conservation. Few techniques currently exist to adequately detect, with high confidence, species that are trap-adverse such as the black rat, Rattus rattus, in high conservation priority areas where multiple non-target species persist. This study investigates the effectiveness of camera trapping for monitoring invasive rodents in high conservation areas, and the influence of habitat features and density of colonial-nesting seabirds on rodent relative activity levels to provide insights into their potential impacts. A total of 276 camera sites were established and left in situ for 8 days. Identified species were recorded in discrete 15 min intervals, referred to as 'events'. In total, 19 804 events were recorded. From these, 31 species were identified comprising 25 native species and six introduced. Two introduced rodent species were detected: the black rat (90% of sites), and house mouse Mus musculus (56% of sites). Rodent activity of both black rats and house mice were positively associated with the structural density of habitats. Density of seabird burrows was not strongly associated with relative activity levels of rodents, yet rodents were still present in these areas. Camera trapping enabled a large number of rodents to be detected with confidence in site-specific absences and high resolution to quantify relative activity levels. This method enables detection of multiple species simultaneously with low impact (for both target and non-target individuals); an ideal strategy for monitoring trap-adverse invasive rodents in high conservation areas.
入侵啮齿动物已在全球80%的岛屿上定居，对岛屿环境造成了严重破坏。与相对的大陆地区相比，岛屿生态系统支持着比例更高的生物多样性，这凸显了它们对全球生物多样性保护的重要性。目前，在多个非目标物种共存的高保护优先级区域，几乎没有技术能够高置信度地充分检测出像黑家鼠（Rattus rattus）这样对陷阱有抵触的物种。本研究调查了相机陷阱在高保护区域监测入侵啮齿动物的有效性，以及栖息地特征和群居海鸟巢穴密度对啮齿动物相对活动水平的影响，以深入了解它们的潜在影响。总共设置了276个相机位点，并在原地放置8天。以离散的15分钟间隔记录识别出的物种，称为“事件”。总共记录了19804个事件。从中识别出31个物种，包括25个本地物种和6个外来物种。检测到两种外来啮齿动物物种：黑家鼠（占位点的90%）和家鼠（Mus musculus，占位点的56%）。黑家鼠和家鼠的啮齿动物活动都与栖息地的结构密度呈正相关。海鸟巢穴的密度与啮齿动物的相对活动水平没有强烈关联，但啮齿动物仍存在于这些区域。相机陷阱能够在特定位点的缺失情况下高置信度地检测到大量啮齿动物，并以高分辨率量化相对活动水平。这种方法能够以低影响（对目标和非目标个体而言）同时检测多个物种；是在高保护区域监测对陷阱有抵触的入侵啮齿动物的理想策略。
