Tuesday, September 30, 2014

Navarre Marsh Weekly Banding Update: September 22-28

This past week a high pressure system set overhead producing variable winds and the nice clear days. Not the best weather for a large volume of nocturnal migrants, however, it was enough to change the speciation to a more October-like guild. We hate to say it, but winter is coming. Winter Wrens (WIWR), Ruby-crowned Kinglets (RCKI), and White-throated Sparrows (WTSP) began their influx into the Lake Erie Marsh Region with Mytle Warbler and Hermit Thrush sure to be close behind. 
Female Golden-winged Warbler
Photo by Ryan Jacob
In spite of the stagnant pressure system we had a nice variety of 21 species of warblers including:Black-and-white Warbler (BAWW), Golden-winged Warbler (GWWA), Tennessee (TEWA), Nashville (NAWA), Northern Parula (NOPA), Magnolia Warbler (MAWA), Cape May Warbler (CMWA), Black-throated Blue (BTBW), Myrtle (MYWA), Blackburnian (BLBW), Bay-breasted (BBWA), Blackpoll (BLPW), Prairie (PRAW), Ovenbird (OVEN), Northern Waterthrush (NOWA), Connecticut (CONW), Mourning (MOWA), Common Yellowthroat (COYE), Wilson's (WIWA),Canada (CAWA), and American Redstart (AMRE). 

Gray Catbirds (GRCA) are still wandering south and this is a good opportunity to see the coverts on a hatching-year (HY) bird. Hatching-year secondary and primary coverts are edged with brown while the adult will be clean gray. By spring time most HY birds will have worn this brown edging off but there are a few that may still show some remnant of it and can then be called second-year (SY) instead of the usual after-hatch-year (AHY). Aging a bird AHY only tells you it was born prior to the previous calendar year. It is important that banders age each bird as definitively as possible to improve the knowledge of the demographics of the populations migrating through the area.

Adult GRCA: Note gray edged primary and secondary coverts.
This bird also had some white feathers under its chin where it is normally gray on GRCAs

GRCA: Hatching -year bird with brown-edged wing coverts

HY GRCA: Note off-color of primary coverts as well as edged with brown.
While identifying birds in the field, there are some individuals that look very different than the images in the field guide. Field guide photos and illustrations try to depict a bird with the most representative field marks for the species. But some birds challenge that image! Below we have a Swainson's Thrush (SWTH) showing very unusual plumage. It has an eye ring and breast spots but the overall feather plumage on this bird is a light gray as compared to a normal SWTH which is olive-brown back and tail.
SWTH with aberrant plumage (left), and "normal" SWTH (right)

Rear view of the SWTHs

Oddly plumaged SWTH with eye ring and spotted chest

Back of this unusual SWTH
It's hard to say what someone in the field might have called this thrush. This individual was run through the wing formulation keys to verify to species. This unusual bird may be more easily seen by predators then the normal more camouflaged plumage and may have long-term survival ramifications. 

Another treat of the week was the female GWWA that graced the station. Thanks to volunteers Ryan Jacob and Don Bauman for providing the photos.
GWWA female with gray mask instead black like the GWWA male
Photo by Don Bauman
This week we saw another banded BLPW recaptured. This bird first visited our nets in September 2011. This is more evidence of the importance of this habitat for fall migrating BLPWS. 

With the next big northerly front we expect to see more kinglets, WTSP, BLPWs, MYWA, HETH, and some juncos. Enjoy the birds as they utilize these important habitats along the lake to stopover and refuel on their journey to their wintering grounds.

For daily banding updates, follow BSBO on Facebook.
Visit the BSBO Website for the seasonal totals.

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