Social status, forest disturbance, and Barred Owls shape long-term trends in breeding dispersal distance of Northern Spotted Owls

Dispersal among breeding sites in territorial animals (i.e. breeding dispersal) is driven by numerous selection pressures, including competition and spatiotemporal variation in habitat quality. The scale and trend of dispersal movements over time may signal changing conditions within the population or on the landscape. We examined 2,158 breeding dispersal events from 694 male and 608 female individually-marked Northern Spotted Owls (Strix occidentalis caurina) monitored over 28 years on seven study areas to assess the relative importance of individual (sex, experience), reproductive (annual productivity, mate availability), and environmental (forest alteration, presence of competitor) sources of variation in breeding dispersal distance. Median breeding dispersal distance was 3.17 km, with 99% of all breeding dispersal events less than 37 km. Mean annual dispersal distances increased by 2.43 km in Oregon and 9.40 km in Washington between 1990 and 2017, which coincided with increases in a...

领地性动物的繁殖位点扩散（即繁殖扩散，breeding dispersal）受多种选择压力驱动，包括竞争与栖息地质量的时空变异。扩散运动的时空规模与年度变化趋势，可反映种群内部或景观层面的环境动态。本研究对7个研究区域内、历经28年监测的1302只（694只雄性、608只雌性）佩戴个体标记的北方斑点鸮（Northern Spotted Owls，Strix occidentalis caurina）的2158次繁殖扩散事件展开分析，旨在评估个体属性（性别、繁殖经验）、繁殖状态（年度繁殖生产力、配偶可获得性）以及环境因素（森林干扰、竞争者存在情况）对繁殖扩散距离变异的相对重要性。繁殖扩散距离的中位数为3.17千米，99%的繁殖扩散事件的扩散距离均小于37千米。1990年至2017年间，俄勒冈州的年均扩散距离增加了2.43千米，华盛顿州则增加了9.40千米，这一变化与……的增长相吻合。