Date: 10/28/19 9:48 am
From: Rob Santry <kingbird...>
Subject: [obol] Re: Grants Pass Costa's Hummer is a hybrid
Hi Group,

 I have some thoughts and some observations on the Costa's/Costa's
hybrid hummingbird vocalizations. So, first, the bird is still here and
active. Ever since we discovered this bird, what is striking and brings
your attention to the bird is the high pitched vocalizations this bird
makes. You know, without looking that the Costa's/ Costa's hybrid is
present. The sounds are different to  any of the sounds an Anna's
Hummingbird makes. Sometimes it is a slow, high-pitched "tsip-tsip" call
to a drawn out quicker "tsip-tsip" series of calls. Those are the only
one's that I have heard. He is doing it now. Courtney and Caleb recorded
another sound. So, we can add that to the repertory of this bird. But,
99% of the sounds that all the observers have heard are of the high
frequency "tsip-tsip" variety. ( Except Dennis, who can't hear those
high frequencies). The experts can quip in and enrich this vocalization
dialogue as to what all our observations mean.

 Ultimately, to some extent, I am always trying to be a trained
observer, so I watch, listen and record. I'll spend more time in the
back yard this morning and listen for the Anna's-type call that Courtney
and Caleb have observed.

I've shared the following thought with Courtney and Caleb. Maybe all the
Costa's Hummingbirds recorded in Southern Oregon have some form of gene
flow or hybridization in them. It may manifest itself in vocalizations
that can be variable, depending on the bird. I don't know, just a
thought. BUT, it does not manifest itself in the visible field marks.

Oh, also, with the tail-pumping behavior, he acts different than Anna's.

As to the length of the bird's tail, I think that this bird has a short
tail. My pictures on ebird show that the tail seems to protrude out
longer than the folded primaries on the wings. I think that in those
pics, the bird is hunched forward and the wings bend up, giving the
impression that they are shorter than the tail. Nolan pointed this out
to me and indeed, in other poses, the tail is short. Nolan, Courtney,
and Caleb can quip in.

 Hopefully, someone can add some clarity of opinion that can jive with
all the observations. That is the fun part and reminds me of all those
late evening discussions of a certain fritillary ID after a butterfly
count :)

Regards,

Rob Santry

Grants Pass



On 10/27/2019 2:14 PM, Bob Archer wrote:
> Not sure why hybrid is being mentioned based solely on song, young
> male Costa's can indeed give a very Anna's like song.  And they molt
> into adult plumage from late fall to early winter.  So feathers are
> growing.
>
> Bob Archer
> PDX
>
> On Sun, Oct 27, 2019 at 12:33 PM <dpvroman...>
> <mailto:<dpvroman...>> wrote:
>
> Was able to view the bird in question yesterday. However, I was
> not able to hear the bird calling with my high frequency hearing
> loss.  The hummingbird's hosts, who can hear the bird, indicated
> that it's call was different than Anna's.  Yesterday, saw two
> hummers attempting to visit the feeder and one closely chased the
> other away. Seen in back light conditions and not able to ID
> either. There is likely Anna's in the area as well.  It can
> sometime be tough to figure out just what bird doing the singing. 
> Will agree that the gorget "ears" looked shorter then other
> Costa's I have seen, why?
>
> Dennis (north of Grants Pass)
>
> On 2019-10-27 11:38, Caleb Centanni wrote:
>
>> Hi all,
>> Courtney and I watched the hummingbird with basically perfect
>> Costa's plumage and callnotes in Grant's Pass this morning, to
>> our dismay, sing a perfect Anna's Hummingbird song. Notes (and
>> later tonight recordings) here:
>> https://ebird.org/view/checklist/S60971902
>> The bird does have slightly short gorget corners and perhaps a
>> slightly long tail, but considering that we and several eBird
>> reviewers called it pure Costa's based on plumage, this raises
>> some serious questions about whether non-singing Costa's
>> Hummingbirds in Oregon can be identified to species. Is there any
>> chance it could be imitating the Anna's song? This seems
>> unlikely, since hummingbirds are non-passerines.
>> Good birding to all,
>> Caleb Centanni
>

 
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