We had a good opportunity to study Eastern Kingbirds. As I mentioned on Friday we don't band that many of them so it was nice to capture an adult and juvenile during the same net round for comparison. Eastern Kingbirds can easily be aged by looking at the color of the greater and median coverts, and the shape of p10 and p9. In juveniles (hatch-year; HY), whitish tips/edging on the greater and median coverts while adults (after hatch-year; AHY), will lack whitish tips/edging. Also, notice the difference in overall wing color between the AHY and HY. The AHY is browner, faded, and more worn compared to the HY. Usually, adult passerines will have a fresher plumage than juveniles because they molt all their flight feathers before fall migration. But AHY Eastern Kingbirds do not molt their flight feathers until they reach their South American wintering grounds so their wing feathers are much older than their HY counterparts who just grew them in a few months ago.
Eastern Kingbird (HY) |
Eastern Kingbird (AHY) |
The other characteristic we look at is the outer two primary feathers (p10 and p9). In AHYs, p10 and p9 will be notched at the tip but in HYs the ends of p10 and p9 will be rounded off. In addition, it is sometimes possible to sex Eastern Kingbirds based on the length of the notching. In general, if the the notch is greater than 8mm it would be a male and less than 8mm would be a female. This individual measured 9.2 mm and we were able to sex it as a male.
Eastern Kingbird (AHY, male) |
Eastern Kingbird (HY, sex unknown) |
This season's banding assistants arrived yesterday afternoon and this morning was their first day at KIBS. I would like to welcome Mattie, Josh, Claire, and Vicki to Kiawah Island and I look forward to a good fall season with them!
NEW BIRDS
1 Great Crested Flycatcher
2 Eastern Kingbird
2 Red-eyed Vireo
1 Carolina Chickadee
1 Blue-gray Gnatcatcher
4 Northern Mockingbird
3 Yellow Warbler
7 Prairie Warbler
7 American Redstart
1 Prothonotary Warbler
2 Worm-eating Warbler
1 Northern Waterthrush
4 Northern Cardinal
17 Painted Bunting
RECAPTURES
2 Northern Cardinal
3 Painted Bunting
BANDING STATS
# of Birds Banded: 53
# of Recaptures: 5
# of Species: 14
Effort: 120.0 net-hours
Capture Rate: 53.5 birds/100 net-hours
# of Nets: 20
FOUR Eastern Kingbirds already this season!? I'm jealous!
ReplyDelete-Novak