In humans, it’s the sperm that determines whether an embryo is pushed along a male or female development pathway. But in birds, it’s the other way around. Eggs are the deciding factor in bird sex.

Part of the woodpecker family, the northern flicker, often known as the common flicker, is a medium-sized bird you can easily ...

In humans, it’s the sperm that determines whether an embryo is pushed along a male or female development pathway. But in birds, it’s the other way around. Eggs are the deciding factor in bird sex.

A rare osprey love triangle has been captured on a live camera feed in the Scottish Borders. Forestry and Land Scotland (FLS) ...

Researchers have spotted an “extremely rare” green honeycreeper in Colombia that’s half female and half male. The bird’s plumage is divided directly down the middle, with blue feathers ...

And for some species, male and female plumage is identical to the ... Prize this year is a Baltimore oriole, which is a bird that people love to see out in the wild, but it still is a pretty ...

Researchers with a team monitoring bird populations at Powdermill Nature Reserve, in Rector, Pennsylvania, netted a surprise on September 24: a rose-breasted grosbeak with bizarre coloring.

“The bird exhibited typical male plumage on its right side and female plumage on the left,” scientists noted, adding that its internal organs were also likely divided down the middle into male ...

Its right side, however, was iridescent blue, the telltale marker of a male. The bird appeared to be a bilateral gynandromorph: female on one side and male on the other. “It was just incredible ...

A striking and extremely rare half female, half male bird has been spotted by a University of Otago zoologist. Sesquicentennial Distinguished Professor Hamish Spencer was holidaying in Colombia ...