当前位置: X-MOL 学术Avian Conserv. Ecol. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Quantifying multiple breeding vital rates in two declining grassland songbirds
Avian Conservation and Ecology ( IF 1.4 ) Pub Date : 2021-06-09 , DOI: 10.5751/ace-01875-160119
Jacy S. Bernath-Plaisted , Arvind O. Panjabi , Nicole A. Guido , Kelsey D. Bell , Nancy E. Drilling , Erin H. Strasser , Sandra K. Johnson , Maureen D. Correll

Many studies of reproductive success in North American songbirds have focused on nesting success, while relatively few have evaluated breeding-season adult survival and post-fledging survival. Grassland songbirds are among North America's most rapidly declining avian groups, and knowledge of factors that influence vital rates is needed to address declines, develop management strategies, and accurately model population limitation. We concurrently monitored nesting success, breeding-season adult survival, and post-fledging survival of two grassland obligates, Baird's Sparrow and Grasshopper sparrow, breeding in western North Dakota and northeastern Montana. Nesting success was monitored by locating and visiting nests at regular intervals while adult and post-fledging survival were assessed by daily telemetry tracking of radio-tagged birds. We analyzed the three variables using logistic exposure and modeled climate, temporal, and vegetative covariates to explain variation in rates. Cumulative nesting success, breeding-season adult survival, and post-fledging survival were 37%, 78%, and 25%, respectively, for Baird's Sparrow and 16%, 74%, and 55% for Grasshopper Sparrow. Both nesting success and post-fledging survival in Baird's Sparrow were responsive to environmental covariates including temporal effects and vertical vegetation structure. Conversely, vital rates of Grasshopper Sparrow were largely unresponsive to covariates we modeled, perhaps because of the species' broader habitat niche relative to Baird's Sparrow. Breeding season adult survival in both species showed little annual variation and was high relative to overwintering survival estimates for the same species, while post-fledging survival in Baird's Sparrow was low and may be a management concern. We suggest as a next step the formal comparison of vital rates across life-stages in an integrated population model capable of identifying sources of population limitation throughout the full annual cycle of the species.

中文翻译:

量化两种衰退草原鸣禽的多重繁殖生命率

许多关于北美鸣禽繁殖成功的研究都集中在筑巢成功上,而很少有人评估繁殖季节的成鸟存活率和羽化后的存活率。草原鸣禽是北美下降速度最快的鸟类之一,需要了解影响生命率的因素来解决下降问题、制定管理策略和准确模拟种群限制。我们同时监测了在北达科他州西部和蒙大拿州东北部繁殖的两种草原专性鸟类贝尔德麻雀和蚱蜢麻雀的筑巢成功率、繁殖季节成体存活率和羽化后存活率。通过定期定位和访问巢穴来监测筑巢成功率,而通过每日遥测跟踪无线电标记的鸟类来评估成年和羽化后的存活率。我们使用逻辑暴露和模拟气候、时间和植物协变量分析了三个变量,以解释速率的变化。Baird's Sparrow 的累积筑巢成功率、繁殖季节成虫存活率和羽化后存活率分别为 37%、78% 和 25%,Grasshopper Sparrow 分别为 16%、74% 和 55%。Baird's Sparrow 的筑巢成功和成活后的存活率都对环境协变量(包括时间效应和垂直植被结构)有反应。相反,Grasshopper Sparrow 的生命率在很大程度上对我们建模的协变量没有反应,这可能是因为该物种相对于 Baird's Sparrow 具有更广泛的栖息地生态位。两个物种的繁殖季节成年存活率几乎没有年度变化,并且相对于同一物种的越冬存活率估计值较高,而贝尔德麻雀的羽化后存活率较低,可能是管理问题。我们建议下一步在综合种群模型中正式比较整个生命阶段的生命率,该模型能够在物种的整个年度周期中确定种群限制的来源。
更新日期:2021-06-09
down
wechat
bug