Anti-parasite treatment results in decreased estimated survival with increasing Pb levels in the common eider Somateria mollissima

Field experiments where parasites are removed through treatment and contaminant levels in host tissues are recorded can provide insight into the combined effects of parasitism and contaminants in wild populations. In 2013 and 2014, we treated northern common eider ducks (Somateria mollissima) arriving at a breeding colony with either a broad-spectrum antihelminthic (PANACUR®) or distilled water, and measured their blood Pb levels. Breeding propensity and clutch sizes were inversely related to Pb in both treatment groups. In comparison, a negative effect of Pb on resight probability the following year was observed only in the anti-parasitic treatment (APT) group. These contrasting patterns suggest a long-term benefit to survival of intestinal parasitism in eiders experiencing Pb exposure. Arrival date of hens explained some, but not all, of the effects of Pb. We weigh the merits of different hypotheses in explaining our results, including protective bioaccumulation of Pb by parasites, co...通过驱虫处理去除寄生虫并同步记录宿主组织中污染物水平的野外实验，可为探究野生种群内寄生作用与污染物的联合效应提供关键研究视角。2013年与2014年，我们对抵达繁殖群落的普通绒鸭（Somateria mollissima）分别施以广谱抗蠕虫药物（PANACUR®）或蒸馏水，并检测其血液铅（Pb）含量。两个处理组中，个体的繁殖倾向与窝卵数均与血液铅水平呈负相关关系。相较而言，仅在抗寄生虫处理（APT）组中观察到铅对个体次年重见概率的负面影响。上述相悖的研究格局表明，在暴露于铅环境的绒鸭种群中，肠道寄生作用对其存活存在长期益处。雌鸭的抵达日期可解释部分（而非全部）铅暴露所产生的效应。我们针对用于解释本次研究结果的不同假说的合理性进行了权衡，其中涵盖寄生虫对铅的保护性生物富集作用、协同……