Multiple accounts of violet-green swallows forming cooperative relationships with other species have been recorded. From 1981 to 1982, three independent swallow pairs were observed co-occupying the nest boxes of western bluebirds. These violet-green swallows protected the nesting site, removed fecal sacs from the boxes and fed the bluebird fledglings with no resistance from the adult western bluebirds. Despite too small of a sample size to hold statistical significance, fledgling survival was greater when violet-green swallows provided active care. It is believed that the swallows benefit from the cooperative relationship by inheriting the nest box after the bluebird parents and fledglings have left.
