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The tough survivors of nesting season

Phoebe feeding a cow bird chick in Mark's yard.
Mark Faherty
Phoebe feeding a cow bird chick in Mark's yard.

Last week’s one-day-wonder American Flamingo, who caused a media frenzy that saw me doing interviews with the likes of USA Today and even somehow the Weather Channel, seems to have settled back on Long Island again. So we’re back to baseline conditions here on the Cape, which means that any tall pink thing you see wading in the shallows is most likely a tourist. No matter, as we have a backlog of old business to attend to here at Bird Report central, namely, what’s going on with breeding birds right now? The answer is, they are battling for their lives and the lives of their children in this war zone we call the suburbs.

It's been a tough breeding season thus far in my yard, with a mix of nest predation and cowbird parasitism keeping nest success low for my local cardinals, catbirds, phoebes, and Song Sparrows. I say thus far because they still have time - both catbirds and cardinals have been building second nests recently and there’s a lot of breeding season left. But the carnage has reached the point where I’m reluctant to tell my kids about the nests, worried it will only lead to heartbreak. The cardinal nest we were watching had pretty old chicks when some mystery predator raided it a few weeks back. And the tragic titmice in the nest box lost their eggs to a raccoon who pulled the whole nest out through the hole.

Brown-headed Cowbirds, who exclusively lay their eggs in the nests of other birds, are one of the many obstacles our birds face in the race to reproduce themselves. These sneaky songbirds were once limited to the short-grass prairies, where they followed bison and laid eggs in the nests of grassland and woodland birds where these habitats met. Agriculture and suburbanization have expanded their habitat to basically everywhere, allowing them access to way more host nests. In my neighborhood, the Eastern Phoebe that nest on my neighbor’s shed often only raise a cowbird chick at the expense of their own, including this year. Check the website for a photo I captured of the duped phoebe aerially feeding the cowbird chick in my yard last week. A pair of Song Sparrows, one of their favorite victims, are also feeding a cowbird chick in another neighbor’s yard as of yesterday, and as I was writing this I discovered a pair of Carolina Wrens feeding a cowbird chick in my front shrubs.

In a continent-wide study of nest predators of North American birds, the top three types were “mesopredators,” which means mid-sized mammals like raccoons, foxes and their ilk, followed by snakes, then rodents, of which Red Squirrel was the worst offender. Though a camera study of nest boxes in Alabama found flying squirrels to be the most common nest predators. Don’t let those adorable, doe-eyed little fur balls fool you—they are cold-blooded killers.

Crows and jays were surprisingly low on the list given their reputation as wonton nest robbers, coming in at 9% of all predation. Less common avian offenders include woodpeckers, who I have seen removing nestlings from nuthatch nests, plus House Wrens and House Sparrows, as anyone who has monitored bluebirds boxes knows. In the weird miscellany category, ants, deer and even cows have been documented eating eggs and baby birds. I personally watched snakes, hawks, mice, and also deer and fire ants devour nestlings in videos I captured during a study of endangered songbird nests in Texas. Everyone’s gotta eat, I reckon.

Don’t forget to add cars — I saved some Blue Jay nestling who fledged into a busy road last week — plus outdoor cats, lawnmowers, and windows to the gauntlet of death for chicks, and it’s miracle our birds fledge any young at all. So next time you see a young bird that made it out of the nest, offer a knowing nod, and a “godspeed” to that little survivor, because he or she has seen some things, man.

Mark Faherty writes the Weekly Bird Report.