There is a lot of racket in the backyard these days — cowbird chicks have fledged and are once again driving their Chipping Sparrow parents crazy with their persistent chirping demands to be fed. I have recently written about the Cowbird’s “Mafia strategy” for getting other species to raise its chicks (you can click here to (re)read that post). The unfortunate Chipping Sparrows seem to be regular hosts for the Cowbirds in my backyard. This is the third year I have seen the diminutive little sparrows foraging intensely to satisfy the appetite of chicks that are twice their size.

Then a foster parent arrives and the cowbird chick goes into a frenzy, fluttering its wings and tail, chirping loudly. The Chipping Sparrow looks a little intimidated, doesn’t it?
And back the parent goes to find something else for this voracious eater it has mistakenly raised. Chipping Sparrows feed their own young, as well as their foster kids, insects, even though they themselves eat a varied diet of seeds, fruit, and insects during the summer. As I watched these host-brood parasite interactions, I saw the adults spend a lot of time hunting damselflies, flies, bees, etc. in the grass around the base of the buckeye tree in which this big baby was sitting.

On this trip, it looks like the sparrow nabbed a damselfly, judging from the long, slender abdomen and wings sticking out of its beak.
The Chipping Sparrows didn’t spend all of their energy feeding the cowbird chick — I could hear them feeding a couple of their own babies that were hiding in the shrubs on the side of the yard.
Excellent photos. You can’t help but feel sorry for the poor sparrow!
I sure do, it’s kind of like having at big kid scream at you all the time, even though you’re trying to help…😃
Nice shots. The difference in size is striking with the sparrow. In my yard it’s usually the cardinals feeding the cowbaby. A few days ago I saw one with a group of newly fledged House Sparrows. They were all ignoring him – I’m not sure where he came from, but thankfully no cardinals were feeding him.
Interesting! I haven’t seen any cardinals subjected to this parasitism, just the chipping sparrows. I’ll have to keep an eye out, though because there are at least a couple of pairs of cardinals feeding chicks in the backyard right now.
I rarely catch them feeding their young, they usually hide in the shrubs at the back fence where I can’t get a photo. But last year, finally, I caught a feeding in the open at one of the bird baths. Little Baby Huey was squawking away for food and I just happened to have my camera nearby on the table.
Thanks for including the link to your blog post — that’s a great shot of the little beggar.
Amazing images, sue. i had heard of this behavior, but I had no idea there was such a size differential between the hosts and the adopted baby. Wow!
It’s my wonderful Buckeye tree that is almost as good as a blind for getting shots of birds (and squirrels) doing their thing. I stood under the tree and the birds pretty much ignored me, fortunately.
Reblogged this on West Los Angeles Bird Club and commented:
This very interesting how one species will foster the offspring of another.
What amazes me most about this is that the sparrows (seemingly) can’t recognize that the cowbird isn’t one of their own. I wonder if they would they still feed it if they could.
It’s interesting how some species can get away with removing cowbird eggs from their nest (e.g., Brown thrashers) while others get the Mafia treatment instead.
I am always amazed and mystified by the ways of nature, well really most things now that I think about it. I loved the photos and the information, really well done.
Thanks, Charlie.
Great photos! Now I bet that big baby will grow up and go into politics.
Yup, the squeaky wheel…
Pingback: Beggars | Back Yard Biology