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.
|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|
|Female WHIP with tan collar|
|Female WHIP tan tail spots. |
This tail color difference is sometimes visible when the bird is in flight
|WHIP in bander's grip|
|Photo showing short legs of WHIP|