Monday, October 20, 2014

Navarre Marsh Banding Update: October 12-19

Male Golden-crowned Kinglet
We are reaching the latter part of fall songbird migration season and the diversity is beginning to diminish; however, the past week recorded a nice variety of warbler species including Tennessee (TEWA), Orange-crowned (OCWA), Nashville (NAWA), Magnolia (MAWA), Black-throated Blue (BTBW), Myrtle Warbler (MYWA), Black-throated Green (BTNW), Western Palm (WPWA), Blackpoll (BLPW), American Redstart (AMRE), Ovenbird (OVEN), Common Yellowthroat (COYE), and Northern Waterthrush (NOWA).

Sparrows have similar field markings but yet are so different. Having birds in the hand offers an opportunity to see what makes up the field mark as well as making size comparisons. Below are two sparrows with breast streaking, where one of the field marks is a dark spot in the center of its chest (Song Sparrow-SOSP) and the other with similar chest markings, but how the streaks come together on the breast do not make a "spot" (Fox Sparrow-FOSP).
SOSP and FOSP: See any "spot" on the SOSP?
Just a series of streaks coming together to form a "spot"
SOSP and FOSP: note bill coloration on both
Backs of the SOSP and FOSP: Note reddish tail of FOSP
Another comparison includes the two Zonotrichia sparrows,
White-throated (WTSP) and White-crowned (WCSP).
WCSP and WTSP: Front view showing bill coloration of both and breast markings. Both birds pictured are hatching-year (HY) birds. For WCSP, HY birds have brown head stripes while adults have black and white stripes on head. The WTSP age is determined by the gray-brown eye. An adult has a red-brown eye (difficult to call in the field through optics).
Generally WCSP are slightly larger than the WTSP
The backs of sparrows display a series of browns and tans
that are very beautiful.
Top: WCSP (HY bird)
 WTSP bottom
FOSP (L) and WCSP (R)
Note  growth bars on the tail of the FOSP depicting symmetrical molt of retrices.

Fall passerine migration will be continuing for at least another month as new species that we think as wintering birds will begin to make there appearance. 

For a broader scope of migration, take a look at the 2014 fall banding numbers and species on our website. 

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