Department of Integrative Biology, The University of Texas at San Antonio, San Antonio, Texas, United States of America.
Biodiversity Research and Teaching Collections, Department of Ecology and Conservation Biology, Texas A&M University, College Station, Texas, United States of America.
PLoS One. 2023 Aug 4;18(8):e0289228. doi: 10.1371/journal.pone.0289228. eCollection 2023.
Owls (Strigiformes) provide myriad ecosystem services and are sentinels for ecosystem health. However, they are at continued risk from anthropogenic threats such as vehicle collisions, entanglement with human-made materials, and exposure to anticoagulant rodenticides (ARs), a widespread pesticide known to affect owls. Texas is an important region for numerous migratory and non-migratory owl species in the United States (US), yet assessments of threats owls face here are lacking preventing the development of informed conservation strategies. This study coupled assessment of admittance data from two wildlife rehabilitation centers in Texas with AR liver screening to (1) identify which species of owls are commonly admitted, (2) evaluate seasonality of admittance, and (3) assess causes of admittance for owls in Texas. Between 2010 and 2021, 1,620 owls were admitted into rehabilitation, representing eight species of which the Great-horned Owl (Bubo virginianus) was the most common. For all owls combined admittance rates were highest in the spring, driven by an influx of juveniles (n = 703, 43.40%). The leading cause of admittance amongst species was 'no apparent injury' (n = 567, 34.94%). Where clear diagnoses could be made, the leading causes of admittances were 'entrapment in human infrastructure' (n = 100, 6.11%) and 'collision with vehicles' (n = 74, 4.56%). While the admittance data did not reveal any cases of AR poisoning, liver screening demonstrated high incidences of AR exposure; of 53 owls screened for ARs, 50.94% (n = 27) tested positive with 18 showing exposure to multiple ARs. Brodifacoum was the most frequently detected AR (n = 19, 43.18%) and seven owls (25.93%) tested positive within lethal ranges. Our results suggest that owls in Texas are at risk from myriad anthropogenic threats and face high exposure rates to ARs. In doing so, our results can inform conservation strategies that mitigate anthropogenic threats faced by owls in Texas and beyond.
猫头鹰（Strigiformes）提供了无数的生态系统服务，是生态系统健康的哨兵。然而，它们仍然持续受到人为威胁的威胁，例如与车辆碰撞、与人为材料纠缠以及接触抗凝血灭鼠剂（AR），这是一种广泛使用的已知会影响猫头鹰的农药。德克萨斯州是美国（US）许多迁徙和非迁徙猫头鹰物种的重要地区，但这里猫头鹰面临的威胁评估却缺乏，这阻碍了制定明智的保护策略。本研究将德克萨斯州两个野生动物康复中心的入场数据评估与 AR 肝脏筛查相结合，以（1）确定哪些猫头鹰物种通常被接纳，（2）评估入场的季节性，以及（3）评估德克萨斯州猫头鹰入场的原因。在 2010 年至 2021 年期间，有 1620 只猫头鹰被送进康复中心，代表了八种物种，其中大角鸮（Bubo virginianus）最为常见。对于所有猫头鹰物种，入场率在春季最高，这是由于大量幼鸟涌入（n = 703，占 43.40%）。入场的主要原因是“无明显损伤”（n = 567，占 34.94%）。在可以明确诊断的情况下，入场的主要原因是“被困在人类基础设施中”（n = 100，占 6.11%）和“与车辆碰撞”（n = 74，占 4.56%）。虽然入场数据没有显示任何 AR 中毒的病例，但肝脏筛查显示出 AR 暴露的高发生率；在 53 只接受 AR 检测的猫头鹰中，有 50.94%（n = 27）呈阳性，其中 18 只显示出对多种 AR 的暴露。溴敌隆是最常检测到的 AR（n = 19，占 43.18%），有 7 只猫头鹰（25.93%）检测到处于致命范围内。我们的结果表明，德克萨斯州的猫头鹰面临着多种人为威胁的风险，并且面临着 AR 高暴露率的风险。这样，我们的结果可以为减轻德克萨斯州和其他地区猫头鹰面临的人为威胁的保护策略提供信息。
