13 June 2017 – Painted Bunting

It’s mid-June and, like clockwork, I found a lady songbird today who looks to have been involved in some post-breeding dispersal.  This one was a Painted Bunting, an ASY-female with a brood patch at the southeastern alcove.

 

At this weird building that is the Noble Research Center, I don’t find many local birds dead at the glass.  There are no feeders, for example. It’s also not a spot that attracts a lot of baby birds.  No, here it’s pretty obvious that migrants are the source of the great majority of the 30–40 victims here each year, with big peaks in mortality during October and May.  There is another, smaller peak, however.

That third peak is “June”.  For some reason, after the collisions of the northbound migrants have died down by the end of May, birds start showing up again in mid-June.  These include migrants as well as local breeders like chickadees and titmice. What’s more, it’s common for these individuals to be females that have recently bred, judging from their brood patches.

Apparently, I am capturing at this site evidence of post-breeding dispersal in females.  It is not clear if these birds are looking for a new mate and territory or if they are dispersing to some specific place to molt. It is also not clear if this post-breeding dispersal involves successful or unsuccessful breeding attempts. With respect to today’s bird, however, I have to assume the latter.

Painted Buntings do not arrive here until the first week or so of May. With another week or so of finding a partner, territorial jostling, etc., that means they aren’t even beginning to nest until mid-May, i.e., about 4 weeks ago. It’s possible for a pair to have raised a brood in 4 weeks I suppose, but if so it would be odd for a female to skip town with fledglings fresh out of the nest.  Thus, it’s more likely that she was dispersing today following a failed breeding attempt.

 

 

15 June 2016 – Number 250

This morning, a dead Tufted Titmouse achieved some grim and arbitrary notoriety as the 250th window-killed bird I’ve found at the Noble Research Center since monitoring began on 20 August 2009. She’s right near the entrance to the northwest alcove, and I left her in place to see how long it takes for her to be removed.

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Like so many birds I find in June, this was a female (AHY) with a brood patch. This one had a faint stripe of mulberry juice down the front of her breast and little on her beak.

 

Intrigued by the pattern, I queried my database for June casualties, 2009–2016.  Out of 22 window-kills, at least 8 have been females with brood patches (and additional 7 might have been but the data weren’t recorded).

13 June 2016 – Field Sparrow

I found a second-year female Field Sparrow at the main north entrance this morning.

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This female too, had a well developed brood patch.  She also had some fat laid down; I’d say coded a 2. Here again, it looks like we’ve got post-breeding dispersal on display.

9–12 June 2016 – casualties [updated]

Thanks to Corey Riding & Co. for checking the Noble Research Center while I was away on 6/9 and 6/10.

The cuckoo and House Finch carcasses remain.

I learned on 6/15 that Chrissy Barton from Corey Riding’s team actually did find a window-killed Black-and-White Warbler on the evening of 6/11.  The bird is a SY female, and I think I see a gap in the breast feathers that would point to a brood patch . . .

 

 

 

7 June 2016 – Carolina Chickadee

“It’s early June – I bet that’s a female with a brood patch.”

Indeed it was.

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5 June 2016 – House Finch

Today marked the first casualty of a species that is common and conspicuous on campus – a House Finch at the southwestern alcove.  As seems to be the case with resident birds, June is evidently a time for post-breeding dispersal, and this bird was, like many June casualties before her, a female with a brood patch.

I left her in place for a removal trial.Screen Shot 2016-06-07 at 9.18.02 AM

 

21 June 2015 – Tufted Titmouse

As reported for May 30 2015, I had observed the beginnings of a pattern when I found the very first window-killed Tufted Titmouse on this project.  That was the second titmouse I’d found on campus during the last week of May, and both were females with brood patches.  In early June of this year, Corey Riding let me know that he had found a Carolina Chickadee dead at Ag Hall – that bird, too, was a female with brood patch.

Today, that emerging pattern got a bit fuzzier when I found just the second dead Tufted Titmouse at the NRC since daily monitoring began in 2009.  This one was an ASY male with fat = 0 in the southwest alcove. So much for patterns, at least that one.

I left this bird in place where it lasted until Thursday, June 25.

DSCF8317 DSCF8318Screen shot 2015-07-05 at 10.35.11 AM