To think I had to come all the way out West to photograph a Yellow Warbler to finally add this “lifer” to my bird list; I’d seen them numerous times along the East Coast but always “missed the shot”. 🙂
While camping in Coalville, Utah, I sighted this male Yellow Warbler flying in and out of a line of trees several times alongside our campsite. I could tell he was quite busy and on a mission.
Losing sight of him in the trees, I continued walking a few steps and saw a perched juvenile Brown-headed Cowbird. He/she gave me several wonderful profile shots.
After the quick photo session, the young Cowbird flew off his perch and up into the trees where I had just sighted the Yellow Warbler.
And just as quick, the Yellow Warbler appeared on the branch next to the Cowbird and fed him an insect.
The Yellow Warbler left and returned so many times, I lost count. The trees must have been full of ‘food’! Each return, the Warbler brought another insect. And at each departure, the young Cowbird begged and cried for more.
So what is going on with these two species?
The Brown-headed Cowbird is North America’s most common “brood parasite.” A female Cowbird makes no nest of her own, but instead lays her eggs in the nests in more than 220 other bird species, who then raise the young Cowbirds as their own.
A Yellow Warbler’s open, cuplike nest is easy to find and widely used by Cowbirds.
The Yellow Warbler can recognize Cowbird eggs, but are too small and cannot get the eggs out of their nests. In some areas, the Warblers try to prevent these parasites by building a new floor over the Cowbird eggs as well as their own eggs, and then laying another new clutch of their own.
In one case, persistent Cowbirds returned five times to lay more eggs in one nest, and an even more persistent Warbler built six layers of nest floors to cover up the Cowbird eggs.
There are times when a Cowbird egg does get incubated, but will unfortunately hatch first, dominating the food supply of the newborn Warblers. The Yellow Warblers will do their best to feed all of them, including the dominant Cowbird who requires and demands much more food than his ‘siblings’.
Notice the juvenile Brown-headed Cowbird is twice the size of the Yellow Warbler. What a tough time for these adoptive parents!
Sometimes, as in the next photo, the Yellow Warbler would stop on the branch and just look at me as if to say, “Will this kid ever be full??!!!”
Such dedication!
It became a double delight to finally capture a Yellow Warbler as well as get to actually see this type of activity unfold before me. I hope you enjoyed my share.
