DNA Extraction
DNA was successfully extracted from all blood/muscle tissue and feather samples either following the DNA extraction protocol by Hillis et al. (1996) based on CTAB reagent for feather and muscle tissue samples or using the QIAamp DNA Mini Kit on blood samples using the manufacturer’s protocol. DNA extraction methods were also developed for use with eggs from captive hens. We obtained DNA by locating and dissecting the perivitelline layer from the egg yolk, rinsing it in phosphate-buffered saline solution and using the QIAamp DNA Investigator Kit to extract DNA. The manufacturer’s ‘Bone and teeth’ extraction protocol was followed due to the high calcium content.