Sigouin Audrey, Bélisle Marc, Garant Dany, Pelletier Fanie
Département de Biologie, Université de Sherbrooke, Sherbrooke, Quebec J1K 2R1, Canada.
Conserv Physiol. 2021 Apr 28;9(1):coab025. doi: 10.1093/conphys/coab025. eCollection 2021.
Agricultural pesticides usage has been increasing globally. These compounds have been developed to disrupt pest species physiology, but because their specificity is limited, they can also have adverse effects on non-target organisms. Recent studies have shown that the damaging toxicological effects of pesticides can be amplified in stressful environments. However, few studies have documented these effects in natural settings where organisms are simultaneously exposed to pesticides and to other environmental stressors such as parasites. In this study, we assessed both pesticide and ectoparasite effects on the physiology of a free-ranging bird. We measured physiological markers including haematocrit, bacteria-killing ability (BKA) and leucocyte counts, as well as exposure to haematophagous larvae, in tree swallow nestlings (), a declining aerial insectivore, in southern Québec, Canada, for over 3 years. We found that combined exposure to pesticides and larvae was negatively related to haematocrit, suggesting possible synergistic effects. However, we found no such relationships with BKA and leucocyte counts, highlighting the complexity of physiological responses to multiple stressors in natural settings. Populations of several aerial insectivores are declining, and although sublethal pesticide effects on physiology are suspected, our results suggest that exposure to other factors, such as parasitism, should also be considered to fully assess these effects, especially because pesticides are increasingly present in the environment.
全球范围内，农业杀虫剂的使用量一直在增加。这些化合物的研发目的是扰乱害虫的生理机能，但由于其特异性有限，它们也可能对非目标生物产生不利影响。最近的研究表明，在压力环境下，杀虫剂的有害毒理学效应会被放大。然而，很少有研究记录在自然环境中，生物体同时接触杀虫剂和其他环境压力源（如寄生虫）时的这些影响。在本研究中，我们评估了杀虫剂和体外寄生虫对一种自由放养鸟类生理机能的影响。我们在加拿大魁北克省南部对树燕雏鸟（一种数量正在减少的食虫鸟类）进行了为期三年多的研究，测量了包括血细胞比容、细菌杀灭能力（BKA）和白细胞计数等生理指标，以及接触吸血幼虫的情况。我们发现，同时接触杀虫剂和幼虫与血细胞比容呈负相关，这表明可能存在协同效应。然而，我们未发现与BKA和白细胞计数有此类关系，这凸显了自然环境中生物体对多种压力源生理反应的复杂性。几种食虫鸟类的种群数量正在减少，尽管怀疑杀虫剂对生理机能有亚致死效应，但我们的结果表明，在全面评估这些影响时，还应考虑接触其他因素，如寄生虫感染，特别是因为环境中杀虫剂的存在越来越普遍。
