Wildlife Health Ghent, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium.
Institute of Biology, Leipzig University, Leipzig, Germany.
Proc Biol Sci. 2023 Sep 27;290(2007):20230510. doi: 10.1098/rspb.2023.0510.
Understanding wildlife responses to novel threats is vital in counteracting biodiversity loss. The emerging pathogen () causes dramatic declines in European salamander populations, and is considered an imminent threat to global amphibian biodiversity. However, real-life disease outcomes remain largely uncharacterized. We performed a multidisciplinary assessment of the longer-term impacts of on highly susceptible fire salamander () populations, by comparing four of the earliest known outbreak sites to uninfected sites. Based on large-scale monitoring efforts, we found population persistence in strongly reduced abundances to over a decade after invasion, but also the extinction of an initially small-sized population. In turn, we found that host responses varied, and detection remained low, within surviving populations. Demographic analyses indicated an ongoing scarcity of large reproductive adults with potential for recruitment failure, while spatial comparisons indicated a population remnant persisting within aberrant habitat. Additionally, we detected no early signs of severe genetic deterioration, yet nor of increased host resistance. Beyond offering additional context to -driven salamander declines, results highlight how the impacts of emerging hypervirulent pathogens can be unpredictable and vary across different levels of biological complexity, and how limited pathogen detectability after population declines may complicate surveillance efforts.
了解野生动物对新出现威胁的反应对于遏制生物多样性丧失至关重要。新兴病原体（）导致欧洲蝾螈数量急剧下降，被认为是对全球两栖动物生物多样性的迫在眉睫的威胁。然而，现实生活中的疾病结果在很大程度上仍未得到描述。我们通过将四个最早已知的暴发地点与未感染地点进行比较，对（）对高度易感的火蝾螈（）种群的长期影响进行了多学科评估。基于大规模监测工作，我们发现，在入侵后十多年，种群仍以大量减少的数量存在，但最初规模较小的种群已经灭绝。反过来，我们发现，宿主的反应各不相同，在幸存的种群中，检测到的（）仍然很低。人口分析表明，持续存在繁殖能力强的成年个体稀缺，可能导致招募失败，而空间比较表明，一个种群残余物在异常的栖息地中持续存在。此外，我们没有检测到严重遗传恶化的早期迹象，但也没有发现宿主抗性增加的迹象。除了为（）驱动的蝾螈下降提供更多背景外，结果还强调了新兴高毒力病原体的影响如何是不可预测的，并在不同层次的生物复杂性上有所不同，以及在种群下降后有限的病原体检测能力如何使监测工作复杂化。
