This is just wild speculation (but what is this group for?); could
these deformities be a result of inadequate gene pool diversity?

I would suspect that these birds no longer need to forage across
wide areas, as they did before we introduced high concentrations
of food in small geographic regions (such as cities, or intensive
crop production), so may no longer be getting to "know" birds from
out of the area...

And my own observations include Brewer's Blackbirds in California
urban areas. Also, perhaps incomplete dietary intake (i.e. lack of
critical nutrients at developing stages of young, or embryonic,
birds)? Certainly these blackbirds don't get much in the way of
fresh insects, feeding mostly on processed foods (and I did notice
tender bedding plants were decimated in some of these open air
malls by the foraging blackbirds).


Michael Patrick
(206) 743-8204
mpatrick at eldec.com

>----------
>From: Raymond Korpi[SMTP:rkorpi at clark.edu]
>Sent: Wednesday, January 15, 1997 8:40 AM
>To: tweeters at u.washington.edu
>Cc: Tweeters
>Subject: Re: A Question about Dove Deformities
>
>I observe such deformities in Brewer's Blackbird flocks quite often.
>When I was working retail in Beaverton, I could id individuals just by
>their leg problems. Ihave seen this often in BRBL's elsewhere as well.
> In Rock Doves, I see some of this as well, especially in places
>where there are bigger flocks. I suspect that the birds may be able to
>cope with these slight problems as they are flock species who do not rely
>heavily on their feet for gathering prey.
> A bander friend of mine back in the Midwest has noticed an
>increased incidence of such deformities in sparrow poulations in the last
>10 years. She tends to band in the same places and at same times every
>year, so there may be some vaiidity to this. Ray K
>
>On Wed, 15 Jan 1997, Dale Goble wrote:
>
>>
>> A friend (who is not on tweeters) asked the following question:
>>
>> I have a very urgent question! I was sitting in an outdoor cafe
>> yesterday eating lunch. As I watched the little doves (tiny grey ones
>> with light blue beaks) I realized that about 1/2 of them had deformed
>> feet. Some had crooked toes while others had no foot at all on one or the
>> other leg. I was really appalled that so many had deformities!!! Would
>> you ask some of your ecology profs what could cause such a thing. I was
>> in downtown Honolulu....
>>
>>
>> i will forward any responses. thanx
>>
>> dale goble
>> moscow
>>
>>
>
>-------------------------------------------------------------------------
>Ray Korpi "A person is a person, no matter how small."
>Hm: Portland, OR --Dr Seuss, "Horton Hears a Who"
>Wk: Clark College
> Vancouver, WA
>rkorpi at clark.edu
>
>