School of Veterinary Medicine, Department of Surgical Sciences, University of Wisconsin, 2015 Linden Drive, Madison, Wisconsin 53706, USA.
Texas State Aquarium, Animal Health, 2710 N Shoreline Boulevard, Corpus Christi, Texas 78402, USA.
J Wildl Dis. 2020 Jul;56(3):673-678. doi: 10.7589/2019-05-124. Epub 2020 Feb 4.
We reviewed necropsy records of 124 Whooping Cranes () recovered following reintroduction of 268 individuals from 2001 to 2016 in the eastern US. Causes of death were determined in 62% (77/124) of cases facilitated by active monitoring that limited decomposition and scavenging artifact. The greatest proportions of mortality were caused by predation (0.468; 95% confidence interval 0.356-0.580; 36/77), collision with power lines or vehicles (0.260; 0.162-0.358; 20/77), and gunshot (0.169; 0.085-0.253; 13/77). Six deaths were attributed to infection (0.078; 0.018-0.138; 6/77), including bacterial and fungal etiologies. Lead analysis of 50 liver samples yielded two results with elevated concentrations (3.65 and 10.97 ppm wet weight), and 10 bone samples from partial carcasses lacking suitable liver tissue resulted in one elevated result (48.82 ppm dry weight). These data indicate that underlying subclinical or clinical lead toxicosis may be a factor in up to 5% of deaths attributed to predation or impact trauma. Brain cholinesterase activity testing indicated no exposure to organophosphate or carbamate pesticides (mean±SD=17.32±2.90 µmol/min/g, 31/71). The causes of death and potential underlying factors summarized in this study constitute the first definitive mortality survey of migratory Whooping Cranes based on a high carcass recovery rate. Causes of death by infectious etiologies remained comparatively rare in this study, and occurred as single cases with no evidence of sustained transmission among reintroduced Whooping Cranes.
我们回顾了 2001 年至 2016 年间在美国东部重新引入的 268 只环颈鹤后，124 只环颈鹤的尸检记录。在 62%（77/124）的病例中，通过限制分解和食腐动物干扰的主动监测确定了死因。死亡率最高的原因是捕食（0.468；95%置信区间 0.356-0.580；36/77）、与输电线或车辆碰撞（0.260；0.162-0.358；20/77）和枪击（0.169；0.085-0.253；13/77）。6 例死亡归因于感染（0.078；0.018-0.138；6/77），包括细菌和真菌感染。对 50 个肝脏样本的铅分析得出了两个浓度升高的结果（湿重 3.65 和 10.97 ppm），10 个来自缺乏合适肝脏组织的部分尸体的骨骼样本得出了一个浓度升高的结果（干重 48.82 ppm）。这些数据表明，潜在的亚临床或临床铅中毒可能是导致 5%的捕食或撞击性创伤归因死亡的一个因素。脑胆碱酯酶活性测试表明，没有接触有机磷或氨基甲酸酯类农药（平均值±SD=17.32±2.90 µmol/min/g，31/71）。本研究总结的死亡原因和潜在因素是首次基于高死亡率对迁徙的白头鹤进行的明确的死亡率调查。在本研究中，由传染性病因引起的死亡仍然相对较少，并且是单个病例，没有证据表明重新引入的白头鹤中有持续传播。
