Hi tweeters,

The Black-headed Grosbeak that was singing up a storm around our yard for a
week left a few days ago, but not before I got good looks at it confirming
it as a first-year male (they are duller than mature males, often with
stripes on the head, and with brown instead of black wings). Every year the
same thing happens - a first-year male sets up a territory including our
yard, sings constantly for a week or two, then disappears when it fails to
attract a female.

Males of many passerine birds have distinctive first-year plumages,
sometimes only evident at close range, other times so different that you
would mistake them for a female (this is the source of some reports of
female birds singing, for example in Purple and Cassin's finches). These
first-year birds probably can't compete with mature males, so they end up in
suboptimal habitat, e.g., city green belts rather than in better habitat out
in the countryside. Not attracting a female is presumably sufficient
evidence that they're not in the best place to be.

All four of the singing male grosbeaks I got a good look at at Spencer
Island last Saturday were first-year birds. I would conclude from this that
Spencer Island isn't optimal habitat for this species either. I heard 2-3x
as many birds singing as I was able to see, but I think my sample was
adequate to point to this somewhat surprising conclusion. I doubt if the
young males are easier to see than the mature ones.

Many of the American Redstarts I've seen singing in northeast Washington
have been young males (female-like), and young males are often
characteristic of the perimeter of a species' range. They are either more
adventuresome (disperse farther) or are displaced by competitive
interactions.

Careful research has shown that a *lot* of the male birds we hear singing in
spring will not be passing on their genes to the next generation. They'll
probably have better luck if they live to the following year.

Dennis Paulson
--
Netta Smith and Dennis Paulson
1724 NE 98 St.
Seattle, WA 98115