Density-habitat relationships of white-tailed deer (Odocoileus virginianus) in Finland

In heterogeneous landscapes, resource selection constitutes a crucial link
between landscape and population-level processes such as density. We
conducted a non-invasive genetic study of white-tailed deer in southern
Finland in 2016 and 2017 using fecal DNA samples to understand factors
influencing white-tailed deer density and space use in late summer prior
to the hunting season. We estimated deer density as a function of
landcover types using a spatial capture-recapture (SCR) model with
individual identities established using microsatellite markers. The study
revealed second-order habitat selection with highest deer densities in
fields and mixed forest, and third-order habitat selection (detection
probability) for transitional woodlands (clear-cuts) and closeness to
fields. Including landscape heterogeneity improved model fit and increased
inferred total density compared with models assuming a homogenous
landscape. Our findings underline the importance of including habitat
covariates when estimating density and exemplifies that resource selection
can be studied using non-invasive methods.

在异质景观中，资源选择是连接景观格局与种群水平过程（如种群密度）的关键纽带。本研究于2016至2017年在芬兰南部开展，采用粪便DNA样本对野生白尾鹿进行非侵入式遗传研究，旨在探明狩猎季前夏末时节，影响白尾鹿种群密度与空间利用模式的各类因素。本研究借助微卫星标记（microsatellite markers）确定个体身份，结合空间捕获-再捕获（Spatial Capture-Recapture, SCR）模型，以土地覆被类型为自变量估算鹿群密度。研究结果显示，白尾鹿存在二级生境选择：农田与混交林内种群密度最高；同时存在三级生境选择，即对过渡性林地（皆伐迹地）及邻近农田的探测概率更高。相较于假设景观均质的模型，纳入景观异质性因子可提升模型拟合度，并提高推算的总种群密度。本研究结果凸显了种群密度估算中纳入生境协变量的重要性，同时证明可通过非侵入式方法开展资源选择相关研究。