28 May 2010 – bonus juvenile cardinal

Nothing at the NRC today, but there was a juvenile Northern Cardinal that met its end at a window of the Food and Agricultural Products Center a mere stone’s throw from where I’m sitting right now in Ag Hall.

One of the primary messages I try to communicate with the window collision issue is that our common, abundant, year-round residents are rarely among the dead beneath our windows. It is the long-distance migrants that make up the lion’s share of casualties. Today’s baby cardinal and the 2 or 3 juvenile Mourning Doves I’ve found this spring illustrate that our residents do occasionally fall victim to windows as well. But it tends not to be the adults in their prime, but the weak, uncoordinated, and inexperienced youngsters who fall victim.

2 thoughts on “28 May 2010 – bonus juvenile cardinal

  1. “But it tends not to be the adults in their prime, but the weak, uncoordinated, and inexperienced youngsters who fall victim.”

    I’ve wondered about this quite a bit – my study had pretty much the same number of young vs. adult residents die (if not more adults), but stunned birds who survived were by far more likely to be adults. So I wonder if perhaps the skull calcification isn’t complete on young birds and they’re more likely to die on impact as a result.

  2. You’re exactly right, Heidi. In fact, banders use the degree of skull ossification as their best method for aging individuals as juvenile or adult when obvious plumage cues aren’t apparent. (If you slick the crown feathers down and look through the transparent skin you can see where the skull is fully ossified and where it is not – with practice, that is!)

    Of course, Dan Klem’s work suggests that probably half of those stunned birds that fly off apparently unharmed will die from their injuries, so the adults may not have *that* big a survival advantage over the juveniles.

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