Sunday, September 21, 2014

Navarre Banding Update

For the week of September 15-21 we observed the first good cold fronts resulting in movements of Gray-cheeked and Swainson's Thrushes and Blackpoll Warblers. There were 19 species of warblers this week which included Black-and-white Warbler (BAWW), Tennessee (TEWA), Nashville (NAWA), Magnolia (MAWA), Cape May (CMWA), Black-throated Blue (BTBW), Black-throated Green (BTNW), Blackburnian (BLBW), Chestnut-sided (CSWA), Bay-breasted (BBWA), BLACKPOLL (BLPW), Ovenbird (OVEN), Northern Waterthrush (NOWA), Connecticut (CONW), Mourning (MOWA), Common Yellowthroat (COYE), Wilson's (WIWA), Golden-winged Warbler (GWWA), and American Redstart (AMRE).

A major benefit of having birds in the hand is to improve aging and sexing techniques in birds. Many species do not have complete aging and sexing keys. Through banding we can make observations, measure morphological 
features, and improve the banding keys. Below is an example of two adult male BAWWs with a variation in the auricular or 'cheek patch.' They both have distinct streaking on the flanks, well rounded primary coverts and alula, and an alula with lots of white coloration in it designating an adult male. Blue arrows are pointing to the alula or wrist feather of the birds. 
BAWW Adult Males: Note variability in cheek patch
BAWW: Adult males with rounded alulas and primary coverts 
Another warbler species which fits well with the confusing fall warblers is the CMWA. The basic plumage has the remnants of the spring facial patterns but are more muted. The auricular patch can still be seen on both female and male (photo below). They have fine breast streaking which can be seen all year. Their bill is thinner than that of BLPWS or BBWAs to fit their feeding style of probing flowers (often showing extensive pollen residues). If you look closely, you can see the yellow coloration of the bottom of their feet (which is a characteristic of BLPWS as well). However, the bill size and shape of the head are quite different than a BLPW.
CMWA: Female on left and male on right
Female CMWAs have two wing bars and males have one larger one.
The CMWA also is one of the warblers with a yellow rump, as you can see below:

CMWA Female: Note the fine streaked breast, fine bill shape and the yellow on head defining where the auricular patch would be prominent in the male spring plumage.

Some highlights of the week that did not get their photo opts earlier:
Brown Thrasher (BRTH): bight yellow eye indicates an adult bird

BRTH: Front shows streaking and size of bill

Golden-winged Warbler (Male)
Interesting that last year during this week we caught a Brewster's Warbler.
This coming week should prove to have excellent species diversity and a large volume of BLPWS. If you have time, get outside and enjoy the official days of FALL. The last Public banding demonstration of the year will be this Saturday (27th) at BSBO at 10 AM. Also check out the season's totals on the BSBO Website. 

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