We sought to investigate the extent to which natural feather availability constrains avian nest construction by provisioning a site with feathers. Twenty patches, each of fifty marked feathers, were made available to naturally breeding passerine birds each week for three breeding seasons. The mean feather loss per week was 14.4% and only in one week of the study did it rise above 40%. The proportion of feathers recovered from local nests of ten passerine species that were marked was less than 3%. It was concluded that natural feather availability is high and that species requiring them for nest building can readily find them.