Institute for Game and Wildlife Research, IREC (CSIC-UCLM-JCCM), Ronda de Toledo, 12, 13005, Ciudad Real, Spain; Department of Animal Science, Faculty of Life Sciences and Engineering, University of Lleida, Av. Alcalde Rovira Roure, 191, 25198, Spain.
Gobierno de Aragón, Subdirección General de Desarrollo Rural y Sostenibilidad, Departamento Medio Ambiente, C/ General Lasheras 8, E-22003 Huesca, Spain.
Environ Pollut. 2022 Dec 15;315:120385. doi: 10.1016/j.envpol.2022.120385. Epub 2022 Oct 15.
The widespread use of second-generation anticoagulant rodenticides (SGARs) and their high persistence in animal tissues has led to these compounds becoming ubiquitous in rodent-predator-scavenger food webs. Exposure to SGARs has usually been investigated in wildlife species found dead, and despite growing evidence of the potential risk of secondary poisoning of predators and scavengers, the current worldwide exposure of free-living scavenging birds to SGARs remains scarcely investigated. We present the first active monitoring of blood SGAR concentrations and prevalence in the four European obligate (i.e., vultures) and facultative (red and black kites) avian scavengers in NE Spain. We analysed 261 free-living birds and detected SGARs in 39.1% (n = 102) of individuals. Both SGAR prevalence and concentrations (ΣSGARs) were related to the age and foraging behaviour of the species studied. Black kites showed the highest prevalence (100%), followed by red kites (66.7%), Egyptian (64.2%), bearded (20.9%), griffon (16.9%) and cinereous (6.3%) vultures. Overall, both the prevalence and average ΣSGARs were higher in non-nestlings than nestlings, and in species such as kites and Egyptian vultures foraging in anthropic landscapes (e.g., landfill sites and livestock farms) and exploiting small/medium-sized carrions. Brodifacoum was most prevalent (28.8%), followed by difenacoum (16.1%), flocoumafen (12.3%) and bromadiolone (7.3%). In SGAR-positive birds, the ΣSGAR (mean ± SE) was 7.52 ± 0.95 ng mL; the highest level detected being 53.50 ng mL. The most abundant diastereomer forms were trans-bromadiolone and flocoumafen, and cis-brodifacoum and difenacoum, showing that lower impact formulations could reduce secondary exposures of non-target species. Our findings suggest that SGARs can bioaccumulate in scavenging birds, showing the potential risk to avian scavenging guilds in Europe and elsewhere. We highlight the need for further studies on the potential adverse effects associated with concentrations of SGARSs in the blood to better interpret active monitoring studies of free-living birds.
第二代抗凝杀鼠剂（SGARs）的广泛使用及其在动物组织中的高持久性，导致这些化合物在啮齿动物-捕食者-食腐动物的食物网中无处不在。通常在发现死亡的野生动物物种中研究 SGAR 的暴露情况，尽管越来越多的证据表明捕食者和食腐动物二次中毒的潜在风险，但目前在全球范围内，自由生活的食腐鸟类暴露于 SGAR 的情况仍鲜有研究。我们首次主动监测了西班牙东北部四种欧洲强制性（即秃鹫）和选择性（红鸢和黑鸢）食腐鸟类的血液中 SGAR 浓度和流行率。我们分析了 261 只自由生活的鸟类，在 39.1%（n=102）的个体中检测到了 SGAR。SGAR 的流行率和浓度（ΣSGARs）均与所研究物种的年龄和觅食行为有关。黑鸢的流行率最高（100%），其次是红鸢（66.7%）、埃及秃鹫（64.2%）、胡须兀鹫（20.9%）、大兀鹫（16.9%）和灰林鵖（6.3%）。总体而言，非雏鸟的流行率和平均ΣSGARs均高于雏鸟，而在鸢和埃及秃鹫等在人为景观中觅食（例如垃圾填埋场和牲畜养殖场）并利用小型/中型腐肉的物种中，这种情况更为明显。溴敌隆的流行率最高（28.8%），其次是敌鼠酮（16.1%）、氟鼠灵（12.3%）和溴鼠灵（7.3%）。在 SGAR 阳性鸟类中，ΣSGAR（平均值±SE）为 7.52±0.95ng mL；检测到的最高水平为 53.50ng mL。最丰富的非对映异构体形式为反式溴敌隆和氟鼠灵，以及顺式溴敌隆和敌鼠酮，这表明低影响配方可以降低非目标物种的二次暴露。我们的研究结果表明，SGARs 可以在食腐鸟类中生物累积，这表明它们对欧洲和其他地区的食腐鸟类群体存在潜在风险。我们强调需要进一步研究血液中 SGARSs 浓度与潜在不良影响之间的关系，以便更好地解释对自由生活鸟类的主动监测研究。
