Diseases and parasites are important drivers of population dynamics in wild mammal populations. Small and endangered populations that overlap with larger, reservoir populations are particularly vulnerable to diseases and parasites, especially in ecosystems highly influenced by climate change. Sarcoptic mange, caused by a parasitic mite Sarcoptes scabiei, constitutes a severe threat to many wildlife populations and is today considered a panzootic. The Scandinavian arctic fox Vulpes lagopus is endangered with a fragmented distribution and is threatened by e.g. red fox Vulpes vulpes expansion, prey scarcity and inbreeding depression. Moreover, one of the subpopulations in Scandinavia has suffered from repeated outbreaks of sarcoptic mange during the past decade, most likely spread by red foxes. This was first documented in 2013 and then again 2014, 2017, 2019, 2020 and 2021. We used field inventories and wildlife cameras to follow the development of sarcoptic mange outbreaks in this arctic fox subpopulation with specific focus on disease transmission and consequences for reproductive output. In 2013–2014, we documented visual symptoms of sarcoptic mange in about 30% of the total population. Despite medical treatment, we demonstrate demographic consequences where the number of arctic fox litters plateaued and litter size was reduced after the introduction of S. scabiei. Furthermore, we found indications that mange likely was transmitted by a few arctic foxes travelling between several dens, i.e. ‘super-spreaders'. This study highlights sarcoptic mange as a severe threat to small populations and can put the persistence of the entire Scandinavian arctic fox population at risk.

中文翻译：

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濒危哺乳动物种群中反复爆发疥癣的后果


疾病和寄生虫是野生哺乳动物种群种群动态的重要驱动因素。与较大的宿主种群重叠的小型濒危种群特别容易受到疾病和寄生虫的侵害，尤其是在受气候变化高度影响的生态系统中。由寄生螨 Sarcoptes scabiei 引起的 Sarcoptic mange 对许多野生动物种群构成严重威胁，今天被认为是一种泛动物病。斯堪的纳维亚北极狐 Vulpes lagopus 分布分散，濒临灭绝，并受到红狐 Vulpes vulpes 等扩张、猎物稀缺和近亲繁殖抑制的威胁。此外，斯堪的纳维亚半岛的一个亚群在过去十年中反复爆发了疥癣，很可能是由红狐传播的。这在 2013 年首次记录，然后在 2014 年、2017 年、2019 年、2020 年和 2021 年再次记录。我们使用野外清单和野生动物相机来跟踪该北极狐亚群中疥癣爆发的发展，特别关注疾病传播和对生殖输出的影响。在 2013-2014 年，我们记录了约 30% 的总人口出现疥癣的视觉症状。尽管进行了药物治疗，但我们证明了在引入 S. scabiei 后北极狐窝数趋于稳定且窝产仔数减少的人口统计学后果。此外，我们发现有迹象表明，疥癣可能是由几只北极狐在多个巢穴之间传播的，即“超级传播者”。这项研究强调，疥癣对小种群构成严重威胁，并可能使整个斯堪的纳维亚北极狐种群的持续存在面临风险。