Subject: Re: TWEETERS digest 1372
Date: Apr 22 19:39:43 1998
From: Jerry & Sandy Converse - sanjer at televar.com


On the last program I saw of "All Bird TV" they said that a female
Cowbird can lay up to 40 eggs in a season and will gather all the young
after they have fledged. Whew--that's alot of gathering!

They also stated that some of the host birds know the egg is not one of
theirs and build a second nest on top on the Cowbirds eggs and her own,
thereby making them unfertile? Does that make it a "fruitless effort".
;-)

Speaking of Cowbirds--we had a M & F at our feeder today.

Jerry Converse
Grand Coulee, WA

Jack Bowling wrote:
>
> ** Reply to note from tweeters at u.washington.edu on Wed, 22 Apr 1998 00:10:55 PDT
>
> > Oh, if only that were true. Unfortunately, cowbirds rarely parasitize House
> > Sparrows because they build a covered nest and cowbirds prefer open nests.
> > Same goes for the starlings and other cavity nesters.
>
> Heard an interesting snippet the other day about cowbirds but can't remember
> just where. It appears that DNA fingerprinting of female cowbirds has revealed
> that the "biological mother" of a cowbird fledgling will stick around the foster
> parents nest(s) and gather up all her young ones. It is believed it is in this
> way that young cowbirds grow to know that they are really cowbirds and not
> sparrows, etc. Fascinating if this is the case and shines a gentler light on
> this often maligned species.
>
> - Jack
>
> ==========================
> Jack Bowling
> Prince George, BC
> jbowling at direct.ca