The First Case of Female-Female Pairing in a Burrow-Nesting Seabird

摘要: Abstract. Previous reports of female-female pairings in seabirds concerned surface-nesting species only and the genetic relatedness between two females has been determined once. Here, first observation a pair (detected by molecular sexing) burrow-nesting seabird is documented. In 2003, female Cory's Shearwaters (Calonectris diomedea) were found incubating same egg, from which chick hatched. A (microsatellite) analysis showed that unrelated. This study provides additional evidence petrel mating systems may be more flexible than initially thought. Female-female pairing might promoted similar factors to seabirds, have remained undetected until now due secretive habits low number studies conducted.