[Tweeters] Re: Scrub-Jays

Kevin Lucas vikingcove at gmail.com
Fri Jul 15 15:21:59 PDT 2016


Carla & Tweeters,

I'm also interested in clear distinctions between California & Woodhouse's
-- distinctions that consider young Scrub-Jays (two-thirds of the 15+
Scrub-Jays around our yard the other afternoon). The young ones are
definitely much lighter gray than the adults, with different shades of
blue. And adults with fresh versus aged plumage. Sometimes light and dark
adult Scrub-Jays simultaneously visit our yard. I look forward to trying
out proposed methods of distinguishing their appearance and vocalizations
-- using the birds in our yard.

On an ABA blog post about the new AOU Supplement,
http://blog.aba.org/2016/07/2016-aou-supplement.html , under the photo of a
Scrub-Jay it says, "...geography plays a huge role–perhaps the only role–in
the ID process." Yet it mentions California as being darker and having a
larger bill than Woodhouse's. But the bird in that photo sure appears
lighter than a Woodhouse's Scrub-Jay on this ABA blog post:
http://blog.aba.org/2016/01/2016-aou-check-list-proposals-part-1.html .
Aren't Woodhouse's supposed to be lighter?

The AOU Supplement, http://www.aoucospubs.org/doi/pdf/10.1642/AUK-16-77.1 ,
describes California Scrub-Jay Distribution as "Casual" here in eastern
Washington. Since we've had Scrub-Jay's in our yards year round in Yakima
and Selah since we moved here in 2009, it's a different idea of "Casual"
than,
"*Code-4:* *Casual.*
Species not recorded annually in the ABA Checklist Area, but with six or
more total records—including three or more in the past 30 years—reflecting
some pattern of occurrence."
Woodhouse's Scrub-Jay Distribution does not mention any part of Washington
state.

It says, "treated as separate on the basis of differences in ecology,
morphology, genetics, and vocalizations; although the two species do
interbreed, the hybrid zone is narrow, and there is evidence for selection
against hybrids." On the ABA blog post it described the hybrid area as
being limited to the Pine Nut Mountains of Storey County, Nevada, as well
as the Reno area. (I don't suppose having a guy named Reno living across
the street would allow me to justify listing a hybrid ;-)

I didn't find any description of the vocal differences.

I'm glad they're gorgeous birds to watch, and fun to listen to, even if I
am not able to honestly and accurately distinguish between two species for
them.

Thanks for your help,
Kevin Lucas
Selah, WA

https://www.aba.org/about/ethics.html
https://www.flickr.com/photos/58148027@N07/

On Fri, Jul 15, 2016 at 12:22 PM, Carla Corin <cw_corin at hotmail.com> wrote:

>

> I've been confused about the descriptions of the two Scrub-Jays,

California and Woodhouse's. I seem to remember something early on
describing the potential California as having more white underparts, and
the Woodhouse's having more grayish underparts. Now all I'm seeing is that
California are "darker" than Woodhouse's. I've seen jays that are darker
blue on the backs and heads (with white underparts) and overall duller jays
with gray underparts (in one occasion both in the same area north of Los
Angeles, in late fall. So, by "darker," are people talking about he darker,
crisper blue ones with the white breasts? Or the grayer darker-breasted
ones?? I people writing about the ALU changes need to get more specific
than just "darker"!

>

> Carla Corin

>

> Sent from my iPad_______________________________________________

> Tweeters mailing list

> Tweeters at u.washington.edu

> http://mailman1.u.washington.edu/mailman/listinfo/tweeters

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