Division of Migratory Bird Management, U.S. Fish and Wildlife Service, 11510 American Holly Drive, Laurel, Maryland, 20708, USA.
College of the Environment, University of Washington, Seattle, Washington, 98195, USA.
Ecol Appl. 2021 Oct;31(7):e02425. doi: 10.1002/eap.2425. Epub 2021 Aug 24.
The management of North American waterfowl is predicated on long-term, continental-scale banding implemented prior to the hunting season (i.e., July-September) and subsequent reporting of bands recovered by hunters. However, single-season banding and encounter operations have a number of characteristics that limit their application to estimating demographic rates and evaluating hypothesized limiting factors throughout the annual cycle. We designed and implemented a two-season banding program for American Black Ducks (Anas rubripes), Mallards (A. platyrhynchos), and hybrids in eastern North America to evaluate potential application to annual life cycle conservation and sport harvest management. We assessed model fit and compared estimates of annual survival among data types (i.e., pre-hunting season only [July-September], post-hunting season only [January-March], and two-season [pre- and post-hunting season]) to evaluate model assumptions and potential application to population modeling and management. There was generally high agreement between estimates of annual survival derived using two-season and pre-season only data for all age and sex cohorts. Estimates of annual survival derived from post-season banding data only were consistently higher for adult females and juveniles of both sexes. We found patterns of seasonal survival varied by species, age, and to a lesser extent, sex. Hunter recovered birds exhibited similar spatial distributions regardless of banding season suggesting banded samples were from the same population. In contrast, goodness-of-fit tests suggest this assumption was statistically violated in some regions and years. We conclude that estimates of seasonal and annual survival for Black Ducks and Mallards based on the two-season banding program are valid and accurate based on model fit statistics, similarity in survival estimates across data and models, and similarities in the distribution of recoveries. The two-season program provides greater precision and insight into the survival process and will improve the ability of researchers and managers to test competing hypotheses regarding population regulation resulting in more effective management.
北美水禽的管理基于长期的大陆尺度的标记工作，这项工作在狩猎季节（即 7 月至 9 月）之前进行，并在狩猎后报告由猎人回收的标记。然而，单季标记和遭遇操作有许多特点，限制了它们在估计整个年度周期内人口率和评估假设限制因素方面的应用。我们设计并实施了一个为期两个季节的美国黑鸭（Anas rubripes）、绿头鸭（A. platyrhynchos）和杂种鸭的标记计划，以评估其在年度生命周期保护和运动收获管理中的潜在应用。我们评估了模型拟合度，并比较了不同数据类型（即仅狩猎前季节[7 月至 9 月]、仅狩猎后季节[1 月至 3 月]和两季[狩猎前和狩猎后季节]）之间的年度存活率估计值，以评估模型假设和对种群建模和管理的潜在应用。对于所有年龄和性别群体，使用两季和仅前季数据得出的年度存活率估计值之间通常具有高度一致性。仅从后季标记数据得出的成年雌性和两性幼鸟的年度存活率估计值始终较高。我们发现季节性存活率的模式因物种、年龄和在较小程度上因性别而异。无论标记季节如何，猎人回收的鸟类表现出相似的空间分布，这表明标记样本来自同一种群。相比之下，拟合优度检验表明，在某些地区和年份，这一假设在统计上是违反的。我们的结论是，基于两季标记计划的黑鸭和绿头鸭的季节性和年度存活率估计值是有效的，并且根据模型拟合统计数据、数据和模型之间的生存估计值的相似性以及回收分布的相似性，是准确的。两季计划提供了对生存过程的更高精度和更深入的了解，并将提高研究人员和管理者测试有关种群调节的竞争假设的能力，从而实现更有效的管理。
