To pluck or not to pluck: the hidden ethical and scientific costs of relying on feathers as a primary source of DNA

Abstract

This article responds to the recent prominence of ornithological literature advocating the plucking or clipping of feathers to obtain DNA in avian studies. We argue that the practise of feather plucking or clipping should be strongly discouraged on both scientific and ethical grounds in the avian literature. Currently, despite claims to the contrary, it is not clear that feather sampling as a source of DNA has lower ethical impacts on birds than blood sampling. In addition, feather samples provide a smaller and less reliable biological resource, significantly jeopardising the short and long-term outcomes that can be gained by the sampling. In contrast, blood collection has been experimentally demonstrated to be relatively safe, subject to operators being skilled and following published guidelines, providing large yields of high quality DNA that facilitates archival storage of samples in a manner that the destructive sampling of feathers cannot.

Amplification success of multilocus genotypes from feathers found in the field compared with feathers obtained from shot birds

“…There is debate on whether feathers are a good source of DNA when the bird has been caught and other material like tissue or blood are available (McDonald & Griffith 2011). Blood sampling has a number of advantages, especially in the long term, and blood or tissue can thus be regarded as more reliable material, as a researcher would not need to be as concerned about a shortage of DNA and there should be fewer problems with respect to PCR amplification.…”

Non-breeding feather concentrations of testosterone, corticosterone and cortisol are associated with subsequent survival in wild house sparrows

“…After the moult, and following routine morphological measurements, approximately five feathers were gently removed from each side of the flanks before releasing the birds. Flank feathers were chosen to avoid damage to flight feathers, and distributed sampling was used to minimize potential thermoregulatory effects of feather-sampling [26]. Feathers were stored in dry zip-lock bags at room temperature until analysis.…”

Sex Determination of Adult Eurasian Coots (Fulica atra) by Morphometric Measurements

“…One of the features that may hamper research on this species is the lack of sexual plumage dimorphism, which makes sex determination difficult in the field. Although molecular sexing has recently become a common tool in avian studies (Ellegren and Sheldon 1997), it is an invasive technique that requires sampling of blood or other tissue that is stressful to the individual and may pose a threat (Brown and Brown 2009;McDonald and Griffith 2011). Therefore, non-invasive sexing techniques, such as morphological sex determination, are highly preferred.…”