Department of Forestry and Natural Resources, University of Kentucky, Lexington, Kentucky, 40546, USA.
Working Land and Seascapes, Conservation Commons, Smithsonian Institution, Washington, D.C., 20013, USA.
Ecol Appl. 2021 Mar;31(2):e02251. doi: 10.1002/eap.2251. Epub 2021 Feb 15.
Pathogenic fungi are increasingly associated with epidemics in wildlife populations. Snake fungal disease (SFD, also referred to as Ophidiomycosis) is an emerging threat to snakes, taxa that are elusive and difficult to sample. Thus, assessments of the effects of SFD on populations have rarely occurred. We used a field technique to enhance detection, Passive Integrated Transponder (PIT) telemetry, and a multi-state capture-mark-recapture model to assess SFD effects on short-term (within-season) survival, movement, and surface activity of two wild snake species, Regina septemvittata (Queensnake) and Nerodia sipedon (Common Watersnake). We were unable to detect an effect of disease state on short-term survival for either species. However, we estimated Bayesian posterior probabilities of >0.99 that R. septemvittata with SFD spent more time surface-active and were less likely to permanently emigrate from the study area. We also estimated probabilities of 0.98 and 0.87 that temporary immigration and temporary emigration rates, respectively, were lower in diseased R. septemvittata. We found evidence of elevated surface activity and lower temporary immigration rates in diseased N. sipedon, with estimated probabilities of 0.89, and found considerably less support for differences in permanent or temporary emigration rates. This study is the first to yield estimates for key demographic and behavioral parameters (survival, emigration, surface activity) of snakes in wild populations afflicted with SFD. Given the increase in surface activity of diseased snakes, future surveys of snake populations could benefit from exploring longer-term demographic consequences of SFD and recognize that disease prevalence in surface-active animals may exceed that of the population as a whole.
致病真菌与野生动物种群的流行疫情越来越相关。蛇真菌病（SFD，也称为蛇霉病）是对蛇类的一种新兴威胁，这些蛇类难以捉摸且难以采样。因此，对 SFD 对种群的影响的评估很少发生。我们使用一种现场技术来增强检测，即无源集成转发器（PIT）遥测技术，以及一种多状态捕获-标记-再捕获模型，以评估 SFD 对两种野生蛇类（Regina septemvittata（皇后蛇）和 Nerodia sipedon（普通水蛇））的短期（季节内）生存、移动和表面活动的影响。我们无法检测到疾病状态对这两个物种的短期生存有影响。然而，我们估计 R. septemvittata 患有 SFD 的后验概率大于 0.99，表明其更多时间处于表面活动状态，不太可能从研究区域永久迁移。我们还估计，患有 SFD 的 R. septemvittata 的临时移民和临时移民率的概率分别为 0.98 和 0.87。我们发现患有 SFD 的 N. sipedon 的表面活动增加和临时移民率降低的证据，其后验概率分别为 0.89，并且对永久性或临时移民率的差异几乎没有更多的支持。本研究首次为受 SFD 影响的野生蛇种群的关键人口和行为参数（生存、移民、表面活动）提供了估计值。鉴于患病蛇类表面活动的增加，未来对蛇类种群的调查可能会受益于探索 SFD 的长期人口后果，并认识到活跃动物的疾病流行率可能超过整个种群的流行率。
