Obtaining DNA Samples from Sensitive and Endangered Bird Species: A Comparison of Saliva and Blood Samples

Methods used to collect biological samples from birds for genetic analyses should allow high-quality DNA to be obtained in sufficient quantities, while limiting negative effects on sampled individuals. In this context, we assessed the potential use of saliva sampling (using buccal swabs) as an alternative to blood sampling (supposedly more stressful) in a near-threatened Caribbean-endemic, the White-crowned Pigeon Patagioenas leucocephala, a bird known to be highly sensitive to capture and handling, based on samples collected from 28 adults captured in the wild. We quantitatively and qualitatively compared DNA extracts, amplifications of two mitochondrial genes (∼430 bp and 1040 bp), and molecular sexing between saliva and blood samples. As expected, blood samples provided larger amounts of DNA of heavy molecular weight than buccal swabs. However, buccal swabs were as reliable as blood samples as a source of genetic material to sequence mtDNA. On the other hand, buccal swab samples might require an improved PCR protocol to sex all individuals successfully. We discuss the use of buccal swabs vs. blood sampling as a way to obtain DNA in relation to research objectives and minimising stress and harmful effects.