Data from: Experimental feeding regime influences urban bird disease dynamics

Wild bird feeding often results in high densities of birds, potentially facilitating transmission of disease. Wild birds are major reservoirs of many zoonotic diseases, and although a number of avian disease outbreaks have been linked to bird feeders, urban bird-feeding and its role in disease systems remains poorly studied. We examined the impacts of typical supplementary feeding practices on the health status of feeder-visiting birds at experimental feeding stations in an urban area of New Zealand. Over an 18-month period, we screened birds captured at feeding and non-feeding properties for three pathogens and four groups of parasites to determine whether feeding altered disease dynamics. We also assessed body condition. All pathogens and parasites were detected in at least one garden bird species. Feeding stations tested positive for Salmonella enterica Typhimurium on ∼7% of occasions, confirming that structures used in feeding are a potential transmission pathway. Feeding influenced some parasite infection parameters; these effects varied among host species. In silvereyes Zosterops lateralis, helminth prevalence and abundance were lower at feeding properties compared to non-feeding properties. In contrast, Eurasian blackbirds Turdus merula at feeding properties had a higher abundance of helminths. House sparrows Passer domesticus at feeding properties had a higher abundance of feather lice. Furthermore, our feeding regime significantly affected body condition in house sparrow and silvereye, though no associations between parasite parameters and body condition indices were found. Our results demonstrate that feeding practices can have varied effects on avian health, including no observable effects for some disease agents in some host species. Disease risks are present, however, thus understanding and reducing these risks should be a key goal for all stakeholders to protect birds that use feeders and other wildlife.野生鸟类投喂常导致种群密度升高，可能会促进疾病传播。野生鸟类是众多人畜共患病（zoonotic diseases）的主要储存宿主；尽管已有多起鸟类疫病暴发与投喂点相关联，但城市鸟类投喂行为及其在疫病传播系统中的作用仍未得到充分研究。本研究于新西兰某城市区域的实验投喂站点开展，旨在探究典型补充投喂行为对到访投喂点的野生鸟类健康状况的影响。研究周期长达18个月，我们对投喂点与非投喂点捕获的鸟类开展了三种病原体与四类寄生虫的筛查，以明确投喂行为是否会改变疾病动态；同时还评估了鸟类的身体状况。所有病原体与寄生虫均在至少一种园林鸟类中被检出。投喂站点约7%的样本呈鼠伤寒沙门氏菌（Salmonella enterica Typhimurium）阳性，这证实了投喂设施可成为潜在的疾病传播途径。投喂行为会对部分寄生虫感染参数产生影响，且该影响因宿主物种而异：对于银眼鸟（Zosterops lateralis），投喂点的蠕虫感染率与感染丰度均低于非投喂点；与之相反，栖息于投喂点的欧亚乌鸫（Turdus merula）的蠕虫感染丰度更高；家麻雀（Passer domesticus）在投喂点的羽虱感染丰度同样更高。此外，本研究采用的投喂方案会显著影响家麻雀与银眼鸟的身体状况，但未发现寄生虫感染参数与身体状况指数之间存在关联。本研究结果表明，投喂行为对鸟类健康的影响存在差异，部分宿主物种的部分病原体感染甚至未表现出明显变化。尽管如此，疾病传播风险依然存在，因此，理解并降低此类风险，应成为所有利益相关方保护依赖投喂点的鸟类及其他野生生物的核心目标。