Jack Dykinga / Yellow-headed blackbirds (Xanthocephalus xanthocephalus) and Redwing blackbirds (Agelaius phoeniceus) roosting. Whitewater Draw Wildlife Area, Arizona, USA, December.

Jack Dykinga / Murmuration of Yellow-headed blackbirds (Xanthocephalus xanthocephalus) and Redwing blackbirds (Agelaius phoeniceus) at sunset, before roosting. Whitewater Draw Wildlife Area, Arizona, USA, December.

Bence Mate / Montezuma oropendola (Psarocolius montezuma) hanging upside down as part of a courtship display. Costa Rica.

Bence Mate / Montezuma oropendola (Psarocolius montezuma) two interacting, Costa Rica.

Bence Mate / Montezuma oropendolas (Psarocolius montezuma) perched either side of Brown-hooded parrot (Pyrilia haematotis) in rain, Laguna del Lagarto, Santa Rita, Costa Rica

Gerrit Vyn / Red-winged blackbirds (Agelaius phoeniceus) in flight. Lower Klamath National Wildlife Refuge, Siskiyou County, California, USA. December.

Bence Mate / Two male blackbirds ( Turdus merula) fighting, Pusztaszer, Kiskunsagi National Park, Hungary

Loic Poidevin / Northern oriole (Icterus galbula) female, Pointe Pelee, Ontario, Canada, May

Pete Oxford / Yellow oriole (Icterus nigrogularis) Bonaire, Netherlands Antilles, Caribbean

Sandesh Kadur / Great-tailed Grackle (Quiscalus mexicanus) roosting on electric lines along Highway 77, Brownsville, Texas, USA. March

David Welling / Brown-headed Cowbird (Molothrus ater) male perched on Cattail, Anahuac National Wildlife Refuge, Texas, USA, June

Marie Read / Yellow-headed Blackbird (Xanthocephalus xanthocephalus) male calling and performing courtship / territorial display in cattail marsh, Mono Lake Basin, California, USA