Monday, November 23, 2009

Baiter Terns re-visited

Windy conditions again meant that the Sandwich Terns were back on the grass.

First year bird with dark primaries and dark centres to tertials.

This bird was begging to the bird on the right for quite some time.

One would assume it was one of its parents but the shot below shows the bird to have dark in the tail.

I was lead to believe that adult birds have white tails. Is this really another 1st year bird born in the same summer, what about a second year?? Or is it an adult that has developed dark in the tail as part of its winter plumage like American Sandwich Tern.
The question I suppose is would a young bird single out an unrelated bird to beg to that isnt its parent? If they dont then this would make it an adult bird with dark in the tail which is interesting.
It would be interesting to know if adult sandvicensis can develop dusky areas in the tail in winter as there have been quite a few birds at Baiter that would easily pass as adult winters however checking back through all the photos nearly all have shown some sort of dark markings in the tail.

Below is a bird with one completely white outer tail feather and one with a dark mark.

Confiding Brent feeding on its own near the beach

On the beach