They were not supposed to meet. She was a common black hawk and he was a red-shouldered hawk. Different genus, different species, and they typically leave in different parts of the continent. But fate brought them together.
It was in 2005 that master raptor bander at Fairfax Raport Research Stan Moore sighted a common black hawk (Buteogallus anthracinus) in the Laguna de Santa Rosa Wetlands Complex in Sonoma County, California. It is a bird of prey that is uncommon in the area as it normally stayed close to river systems. As years went on, Moore realized the black hawk became a resident of the lands.
“The Laguna de Santa Rosa Wetland is a very rich place that has great feeding opportunitues, and so that could be part of [why it stuck around],” Jennifer Coulson, population ecologist at Tulane University in New Orleans and president of the Orleans Audobon Society, told Gizmodo.
In 2009, Moore captured and tagged the hawk, determining it was a female. During the same time, he observed the black hawk to display mating towards a local red-shouldered hawk (Buteo lineatus). It dd not go very well and the female was rejected and chased away.
Red-shouldered hawk are an entirely different species than the black hawk. They are often found in eastern North America and a coastal strip in California. They are smaller than black hawks and have a rather colored rusty plumage.
But after years of unrequited courting, Moore and Coulson revealed in their study published in the Journal of Raptor Research that the two species finally clicked.
In 2012, a bird watcher happened to spot what appeared to be a hybrid juvenile hawk.
The common black hawk was seen mating with the red-shouldered hawk and tending to a nest in 2013, and in 2014, Moore spotted their hybrid nesting.
The hybrid had a dark plumage on its back and was big like its mother. But, its head was round with a hooked bill and narrow jaw, features from its father.
“The common black hawk, as a juvenile, has a really striking face pattern, with a lot of white or cream color with some bold dark brown,” Coulson said.
She added that finding the two hawks and its hybrid is “a big deal.”
“That doesn’t happen often in hardly anything, especially not in predators,” Coulson said, noting that black hawks are often the bigger of the two species, so the size contrast puts the male in significant physical peril.