Monday, May 4, 2015

Navarre Marsh Banding Station Update: April 28 - May 3rd

April ended with cooler temps and little movement of spring migrants. Since the birds were backed up by the easterly and northerly winds it has been like opening flood gates once a favorable wind came. Starting on Friday the wind pattern we have been waiting for started. Twenty species of warblers were observed and/or captured including: Ovenbird (OVEN), Worm-eating (WEWA), Northern Waterthrush (NOWA), Golden-wing (GWWA), Blue-winged (BWWA), Black-and-white (BAWW) Prothonotary (PROW), Orange-crowned (OCWA), Nashville (NAWA), Common Yellowthroat (COYE), American Redstart (AMRE), Northern Parula (NOPA) Blackburnian (BLBW), Yellow (YEWA), Blackpoll (BLPW), Black-throated Blue (BTBW), Western Palm (WPWA), Pine (PIWA), Myrtle (MYWA), and Black-throated Green (BTNW). 

Banding gives an opportunity to acquire more definitive population information such as age ratios and sex of some species. More work is needed on many passerines to determine sex in monomorphic species.
With the southerly winds, thousands of Blue Jays (BLJA) were observed migrating. This species prefers to not cross open water and can be observed milling about and backtracking along the lakeshore. Shown below is a BLJA wing showing the primary coverts which generally is only molted once a year (each Summer during the basic molt) which provides a good indicator for ageing many passerines. This is a combination of wear differences of a hatching year bird growing all feathers at once and an adult that is conducting a sequential molt resulting in stronger feather structure.

BLJA SY (Second-year) Hatched last summer.
Note primary coverts are dull gray blue with no barring in the feather
BLJA ASY (After second-year) wing.
 Note barring on primary coverts and nice blue iridescence.
One of the highlights this week was the capture a male Whip-poor-will (WHIP). Males have white spots on their tail and a white ring under their chin.
Male WHIP with white white collar
Note long rictal bristles(look like cat whiskers) to aid in capturing bugs
Male WHIP large white tail spots
  Females have a tannish ring under their chin and tan tail spots.
Female WHIP with tan collar
Female WHIP tan tail spots.
This tail color difference is sometimes visible when the bird is in flight
Note the method these birds are being held. Nightjars should only be held in the banders grip to protect leg and wing damage that could result from leg holds. 
WHIP in bander's grip

Photo showing short legs of WHIP
Spring has sprung so take some time this week to enjoy the early May songbirds. We also encourage you to join us for our free banding demonstration this Saturday at 10:00 AM at the Observatory visitors' center (just inside the entrance to Magee Marsh). 

No comments:

Post a Comment