Effects of blood collection on wild birds: an update

Blood sampling is often critical for answering a variety of questions about wild birds. However, it is important to assess the impacts, if any, of blood collection on wild birds. Here, we examined the effects of blood sampling on adults or nestlings in three species of free-living birds. First, we examined the effects of blood collection on annual survival and reproductive success in adult buff-breasted wrens Thryothorus leucotis in Panama. In adult wrens, blood collection from the brachial vein during the breeding season had no effect on annual survival or reproductive success. Second, we examined whether blood collection influenced mass gain in developing smooth-billed anis Crotophaga ani in Puerto Rico. In developing anis, blood collection from the femoral or jugular veins had no effect on mass gain of nestlings. Third, in developing European starlings Sturnus vulgaris in British Columbia, Canada, blood collection from the brachial vein had no effect of body condition. Blood collection from the jugular vein had a transient effect on body condition during the first week post-hatch, but this effect disappeared by the second week of age. Lastly, we present an extensive up-to-date review of the literature on the effects of blood collection on free-living avian species. Taken together, these data show that blood collection has no major negative effects on developing or adult birds in the wild.