Erlend Haarberg / Brambling (Fringilla montifringilla) fighting. Vauldalen, Sor-trondelag. Norway, May.

Anup Shah / Lesser Flamingo {Phoeniconaias minor} nesting neighbours bickering, Lake Nakuru, Kenya.

Roger Powell / Great Bustard (Otis tarda) females gathering and bickering with each other for dominance on the edge of the main lek area. Castro Verde, Portugal, April

Staffan Widstrand / Four Black vultures (Coragyps atratus) fighting over a Caiman (Caiman yacare) carcass in river, Cuiaba River, Pantanal wetlands, Mato Grosso, Brazil.

Gabriel Rojo / Two Giant petrels (Macronectes giganteus) bickering on beach, Peninsula Valdes, Patagonia, Argentina.

Doug Gimesy / Grey-headed flying-fox (Pteropus poliocephalus) male involved in courtship / mating behaviour including licking female's genitalia; male grooming his own penis, bickering and female climbing away, Yar...

Doug Gimesy / Grey-headed flying-fox (Pteropus poliocephalus) male courtship / mating behaviour with female including licking her genitalia, then bickering, before male grooms his own penis, Yarra Bend Park, Victor...

Roger Powell / Two Black-legged Kittiwake (Rissa tridactyla) squabbling over ownership of a nest, Howick Haven, Nothumberland, UK. March.

David Tipling / Two Blackbirds (Turdus merula) male and female squabbling in snowy garden, North Norfolk, UK. February.

David Tipling / Two Blackbird (Turdus merula) squabbling in snowy garden, North Norfolk, UK. February.

David Tipling / Two Black-legged kittiwake (Rissa tridactyla) squabbling mid-air, Bempton Cliffs, Yorkshire, UK. June.

Bruce Thomson / Two Spiny-cheeked honeyeater (Acanthagenys rufogularis) bickering on branch near waterhole, Cunnamulla, Queensland, Australia.