Lewis William B, Nater Chloé R, Rectenwald Justin A, Sisson D Clay, Martin James A
Warnell School of Forestry and Natural Resources, University of Georgia, Athens, Georgia, United States.
Norwegian Institute for Nature Research, Trondheim, Norway.
PeerJ. 2024 Dec 4;12:e18625. doi: 10.7717/peerj.18625. eCollection 2024.
Management of wildlife populations is most effective with a thorough understanding of the interplay among vital rates, population growth, and density-dependent feedback; however, measuring all relevant vital rates and assessing density-dependence can prove challenging. Integrated population models have been proposed as a method to address these issues, as they allow for direct modeling of density-dependent pathways and inference on parameters without direct data. We developed integrated population models from a 25-year demography dataset of Northern Bobwhites () from southern Georgia, USA, to assess the demographic drivers of population growth rates and to estimate the strength of multiple density-dependent processes simultaneously. Furthermore, we utilize a novel approach combining breeding productivity and post-breeding abundance and age-and-sex ratio data to infer juvenile survival. Population abundance was relatively stable for the first 14 years of the study but began growing after 2012, showing that bobwhite populations may be stable or exhibit positive population growth in areas of intensive management. Variation in breeding and non-breeding survival drove changes in population growth in a few years; however, population growth rates were most affected by productivity across the entire study duration. A similar pattern was observed for density-dependence, with relatively stronger negative effects of density on productivity than on survival. Our novel modeling approach required an informative prior but was successful at updating the prior distribution for juvenile survival. Our results show that integrated population models provide an attractive and flexible method for directly modeling all relevant density-dependent processes and for combining breeding and post-breeding data to estimate juvenile survival in the absence of direct data.
对野生动物种群的管理,若能透彻理解关键率、种群增长和密度依赖反馈之间的相互作用,则最为有效;然而,测量所有相关关键率并评估密度依赖性可能颇具挑战。综合种群模型已被提议作为解决这些问题的一种方法,因为它们允许对密度依赖途径进行直接建模,并在没有直接数据的情况下对参数进行推断。我们利用来自美国佐治亚州南部的北方 Bobwhites(学名:Colinus virginianus)25 年的种群统计学数据集开发了综合种群模型,以评估种群增长率的人口统计学驱动因素,并同时估计多种密度依赖过程的强度。此外,我们采用了一种新颖的方法,将繁殖生产力与繁殖后丰度以及年龄和性别比例数据相结合,以推断幼体存活率。在研究的前 14 年中,种群丰度相对稳定,但在 2012 年之后开始增长,这表明在集约管理地区,Bobwhite 种群可能稳定或呈现正增长。在某些年份,繁殖和非繁殖存活率的变化推动了种群增长的变化;然而,在整个研究期间,种群增长率受生产力的影响最大。在密度依赖性方面也观察到类似模式,密度对生产力的负面影响相对强于对存活率的影响。我们新颖的建模方法需要一个信息丰富的先验分布,但成功地更新了幼体存活率的先验分布。我们的结果表明,综合种群模型为直接对所有相关的密度依赖过程进行建模,以及在没有直接数据的情况下结合繁殖和繁殖后数据来估计幼体存活率提供了一种有吸引力且灵活的方法。