Department of Zoology, State Museum of Natural History Stuttgart, Stuttgart, Germany.
Center of Excellence for Biodiversity and Integrative Taxonomy, University of Hohenheim, Stuttgart, Germany.
PeerJ. 2022 Aug 4;10:e13685. doi: 10.7717/peerj.13685. eCollection 2022.
In the late eighties, Greylag Geese () started to colonise an urban area previously void of geese in southwestern Germany. Between 2004 and 2020, in a period of steady population increase with subsequent population stagnation, we analysed two measures of reproductive success: (1) the relation between freshly hatched to fledged young for each brood and (2) the probability of a hatchling to survive to fledging. We were able to show that the dispersal of pairs from the nesting site to a different brood rearing area resulted in higher reproductive success. However, the increasing population size of Greylag Geese and the number of breeding pairs of recently immigrated Egyptian Geese () had a negative impact on reproductive success, indicating density dependence. Our results show that newly established populations in urban settings do not grow indefinitely, which is an important fact that should be taken into account by wildlife managers.
在 80 年代后期，灰雁（）开始在德国西南部的一个以前没有鹅的城市地区繁殖。在 2004 年至 2020 年期间，在种群持续增长随后停滞的过程中，我们分析了两个生殖成功的指标：（1）每窝刚孵出到离巢的幼鹅数量的关系，以及（2）雏鹅成活到离巢的概率。我们能够表明，对不同育雏区的配对的扩散导致更高的生殖成功率。然而，灰雁种群的不断增加和最近移民的埃及鹅（）的繁殖对的数量对生殖成功率产生了负面影响，表明存在密度依赖性。我们的研究结果表明，城市环境中新建立的种群不会无限增长，这是野生动物管理者应该考虑的一个重要事实。
