Trulio Lynne A, Chromczak Debra A, Higgins Philip G
Department of Environmental Studies, San José State University, San Jose, California, United States of America.
Environmental Researcher and Consultant, Riegelsville, Pennsylvania, United States of America.
PLoS One. 2025 Jun 25;20(6):e0326160. doi: 10.1371/journal.pone.0326160. eCollection 2025.
As urbanization reduces species' habitats and population sizes, managers need information on whether within-population processes, such as changes in mate and nest-site fidelity and dispersal distances, may be contributing to declines. Few avian studies have examined changes in these behaviors in declining populations or in urban settings. We investigated whether mate fidelity, nest-site fidelity or breeding dispersal distance changed over time in a population of burrowing owls (Athene cunicularia), a short-lived, socially-monogamous species. During the 18-year period of the study, the population declined by 69% in urban Santa Clara County, California, USA--a region of rapid urbanization. We assessed whether these behaviors were influenced by key factors including age, breeding success in the previous year, and years with the same mate, and examined the relationship between mate and nest-site fidelity over time and annual reproductive success. Our analyses showed no change over time in mate fidelity rates, nest-site fidelity rates, dispersal distances or annual reproductive success, indicating these behaviors remained stable even during a severe population decline. Although burrowing owls are a short-lived species, we found that increasing years with the same mate resulted in increased nest-site fidelity and annual reproductive success. To achieve increasing annual reproductive success in this species and others with similar fidelity behaviors, nest sites and pairs must be protected over many years allowing mates to stay together in the same nest territory. Since these fidelity behaviors were maintained during the population decline, other factors require investigation to determine the causes for decreases in this population. Burrowing owls are an urban-adaptable species that can maintain important fidelity behaviors in human-altered habitats. However, even such species are subject to population declines in urban settings.
随着城市化进程的推进，物种的栖息地和种群规模不断减小，管理者需要了解种群内部的一些过程，比如配偶和巢址忠诚度的变化以及扩散距离的改变，是否会导致种群数量下降。很少有鸟类研究调查过数量下降的种群或城市环境中这些行为的变化。我们调查了穴小鸮（Athene cunicularia）种群中配偶忠诚度、巢址忠诚度或繁殖扩散距离是否随时间发生变化，穴小鸮是一种寿命较短、实行社会单配制的物种。在为期18年的研究期间，美国加利福尼亚州圣克拉拉县城市地区的穴小鸮种群数量下降了69%，该地区正处于快速城市化阶段。我们评估了这些行为是否受到年龄、上一年繁殖成功率以及与同一配偶相处的年份等关键因素的影响，并研究了配偶忠诚度和巢址忠诚度随时间的变化与年度繁殖成功率之间的关系。我们的分析表明，配偶忠诚度、巢址忠诚度、扩散距离或年度繁殖成功率均未随时间发生变化，这表明即使在种群数量严重下降期间，这些行为仍保持稳定。尽管穴小鸮是一种寿命较短的物种，但我们发现与同一配偶相处的年份增加会导致巢址忠诚度和年度繁殖成功率提高。为了在该物种以及其他具有类似忠诚度行为的物种中实现年度繁殖成功率的提高，必须在多年内保护巢址和配偶对，使配偶能够在同一巢域内共同生活。由于在种群数量下降期间这些忠诚度行为得以维持，因此需要调查其他因素以确定该种群数量减少的原因。穴小鸮是一种适应城市环境的物种，能够在人类改变的栖息地中维持重要的忠诚度行为。然而，即使是这样的物种在城市环境中也会面临种群数量下降的情况。
