Subject: Ruffed Grouse?
Date: Oct 15 13:07:22 1999
From: WAYNE WEBER - WAYNE_WEBER at bc.sympatico.ca


Tweeters,

From Christy's description, I would say the bird she heard was
certainly a Ruffed Grouse.
Although several Tweeters followed up on Christy's message with
Ruffed Grouse observations of their own, I have not seen a response to
her question about why a Ruffed Grouse would be drumming in October. I
have heard them drumming several times in October myself. It is not
that unusual, although they do not drum in fall nearly as often or as
persistently as in spring.
For those of you who are not familiar with it, the phenomenon of
"gonadal recrudescence" is believed to be responsible for autumn
drumming by Ruffed Grouse and autumn singing by many other species.
Singing and other forms of courtship and territorial behavior are
dependent on high levels of androgens (male hormones). Unlike many
mammals, most male birds do not produce steady levels of male hormones
year-round. The gonads are large and active from early spring through
midsummer, but then they regress, and song and courtship behaviour
largely cease. However, in some species, under some conditions, there
is a partial recovery of the gonads for a while in the fall, and a
resumption of song (or drumming, in Ruffed Grouse), at least for a few
weeks. Sharp-tailed Grouse, for instance, are known to visit their
springtime leks (display grounds) during the fall.
I was just involved in a discussion on OBOL about fall singing by
Cassin's (formerly Solitary) Vireos, which has the same explanation.
I hope that answers your question, Christy.

Wayne Weber
Kamloops, B.C.
wayne_weber at bc.sympatico.ca



-----Original Message-----
From: Christy Anderson <christya at gte.net>
To: Tweeters <tweeters at u.washington.edu>
Date: Sunday, October 10, 1999 7:58 PM
Subject: Ruffed Grouse?


>Two of us hiked around Ledbetter Point on the Long Beach peninsula
>yesterday. We were watching some loons when we heard a sound neither
of us
>had heard before. A grouse drumming! It started very slow and
gradually
>increased speed until it was a low frequency roll. It was as though
we FELT
>it more than heard it. It was coming from back in the woods and
seemed quite
>close. Going by the guide books, we surmised RUFFED GROUSE. Good
guess? But
>why was it drumming this time of year? Any input on what we might
have heard
>is welcome.
>
>Christy Anderson
>Bellevue WA
>christya at gte.net
>