Department of Natural Resources, Science, and Management, University of Minnesota, St. Paul, Minnesota, USA.
PLoS One. 2009 Sep 16;4(9):e7042. doi: 10.1371/journal.pone.0007042.
Gray wolves (Canis lupus) were reintroduced into Yellowstone National Park (YNP) after a >70 year absence, and as part of recovery efforts, the population has been closely monitored. In 1999 and 2005, pup survival was significantly reduced, suggestive of disease outbreaks.
METHODOLOGY/PRINCIPAL FINDINGS: We analyzed sympatric wolf, coyote (Canis latrans), and red fox (Vulpes vulpes) serologic data from YNP, spanning 1991-2007, to identify long-term patterns of pathogen exposure, identify associated risk factors, and examine evidence for disease-induced mortality among wolves for which there were survival data. We found high, constant exposure to canine parvovirus (wolf seroprevalence: 100%; coyote: 94%), canine adenovirus-1 (wolf pups [0.5-0.9 yr]: 91%, adults [>or=1 yr]: 96%; coyote juveniles [0.5-1.5 yrs]: 18%, adults [>or=1.6 yrs]: 83%), and canine herpesvirus (wolf: 87%; coyote juveniles: 23%, young adults [1.6-4.9 yrs]: 51%, old adults [>or=5 yrs]: 87%) suggesting that these pathogens were enzootic within YNP wolves and coyotes. An average of 50% of wolves exhibited exposure to the protozoan parasite, Neospora caninum, although individuals' odds of exposure tended to increase with age and was temporally variable. Wolf, coyote, and fox exposure to canine distemper virus (CDV) was temporally variable, with evidence for distinct multi-host outbreaks in 1999 and 2005, and perhaps a smaller, isolated outbreak among wolves in the interior of YNP in 2002. The years of high wolf-pup mortality in 1999 and 2005 in the northern region of the park were correlated with peaks in CDV seroprevalence, suggesting that CDV contributed to the observed mortality.
CONCLUSIONS/SIGNIFICANCE: Of the pathogens we examined, none appear to jeopardize the long-term population of canids in YNP. However, CDV appears capable of causing short-term population declines. Additional information on how and where CDV is maintained and the frequency with which future epizootics might be expected might be useful for future management of the Northern Rocky Mountain wolf population.
灰狼（Canis lupus）在 70 多年的消失后重新引入黄石国家公园（YNP），作为恢复工作的一部分，该种群受到了密切监测。1999 年和 2005 年，幼崽存活率显著降低，表明出现了疾病爆发。
方法/主要发现：我们分析了 1991 年至 2007 年黄石公园共生狼、郊狼（Canis latrans）和红狐（Vulpes vulpes）的血清学数据，以确定病原体暴露的长期模式，确定相关风险因素，并检查有生存数据的狼是否存在疾病引起的死亡率。我们发现犬细小病毒（狼血清阳性率：100%；郊狼：94%）、犬腺病毒-1（狼幼崽[0.5-0.9 岁]：91%，成年狼[>或=1 岁]：96%；郊狼幼崽[0.5-1.5 岁]：18%，成年郊狼[>或=1.6 岁]：83%）和犬疱疹病毒（狼：87%；郊狼幼崽：23%，年轻成年郊狼[1.6-4.9 岁]：51%，老年成年郊狼[>或=5 岁]：87%）的高、持续暴露表明这些病原体在 YNP 狼和郊狼中是地方性的。平均有 50%的狼表现出对原生动物寄生虫新孢子虫（Neospora caninum）的暴露，尽管个体的暴露几率随着年龄的增长而增加，且在时间上是可变的。狼、郊狼和狐狸对犬瘟热病毒（CDV）的暴露是时间上可变的，1999 年和 2005 年有明显的多宿主爆发的证据，2002 年在 YNP 内部地区可能有较小的孤立爆发。公园北部地区 1999 年和 2005 年幼狼死亡率高的年份与 CDV 血清阳性率的峰值相关，表明 CDV 导致了观察到的死亡率。
结论/意义：在所检查的病原体中，没有一种似乎危及 YNP 中犬科动物的长期种群。然而，CDV 似乎能够造成短期的种群减少。有关 CDV 如何以及在哪里维持以及未来可能发生的疫情频率的更多信息，可能对未来管理北落基山狼种群有用。
