Date: 10/30/19 10:22 am
From: Tim Rodenkirk <timrodenkirk...>
Subject: [obol] Re: Costa's probably hybrid
OK I’ll jump into this. If one was looking for an Allen’s Hummer in SW OR
given the current info on hybrids, I’d make sure the candidate had ALL of
the following:

-Male
-Entirely green-backed (not 50 or 75% green which I believe may be common
in hybrids)
-Preferable further south, Brookings would be ideal (Bandon to Port Orford
is loaded with what appear to be partially green-backed hybrids)
-And the Allen’s type display was observed.

If you haven’t checked all the above boxes you cannot be reasonably sure
you didn’t see a hybrid (an entirely green-backed male could be found
further north- just that gets you closer to the center of the hybrid zone).

With the Anna’s/Costa complex I would think you would want everything to
check out against hybrid including song as otherwise you are still guessing
that it is probably not a hybrid- not sure you will ever get that “I am
absolutely sure it was not a hybrid” with the bird in question?

My two cents,
Tim Rodenkirk
Coos Bay



On Wed, Oct 30, 2019 at 8:54 AM Alan Contreras <acontrer56...> wrote:

> Old articles from Auk are available on the SORA database.
>
> https://sora.unm.edu
>
> I would use more modern sources before the 1978 article, in part because
> more is known now. The problem here is that we have two competing truths:
>
> a. hummingbirds can learn songs
> b. hybrids can sing the song of a parent
>
> It seems to me that these things more or less cancel out and we are left
> with plumage and structure.
>
>
> Alan Contreras
> <acontrer56...>
> Eugene, Oregon
>
> www.alanlcontreras.com
>
> Attending Christmas Bird Counts with good weather forecasts.
>
>
>
>
>
>
>
>
>
> On Oct 30, 2019, at 8:40 AM, <rriparia...> wrote:
>
> Looking further into this bird,
>
> I found an article:
>
> Wells at. al. , 1978, Auk 95
>
> The abstract discusses hybrids between Costa's and Anna's with males
> appearing most like Costa's and giving a song typical of Anna's.
>
> I did not have access to and did not read the article.
>
> Maybe others have already concluded that this bird is likely a hybrid, so
> I'm a little slow here. I thought it was interesting that observations of
> this bird are supported in this cited literature.
>
> *Sent from my Verizon LG Smartphone*
>
>
>

 
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