Date: 10/30/20 6:18 pm
From: Robert O'Brien <baro...>
Subject: [obol] Re: Woodhouse vs. California Scrub Jays an eBird suggestion
I certainly agree on the Death Valley birds re: Oregon/Nevada birds but
this does show the potential plumage variability.
A further interesting note, Single Leaf Pinons were abundant in Caruther's
Canyon.
Bob OBrien


On Fri, Oct 30, 2020 at 3:00 PM Joel Geier <clearwater...> wrote:

> First, I'd like to correct a misquotation by Bob O'Brien.
>
> I didn't say that "none of the Scrub Jay OBOL-commenters have
> experience with these species south of the Oregon border." Rather I noted
> that none of them "have yet
> offered any personal experience with scrub-jays from south of the
> Oregon/Nevada state line."
>
> Within the context of the current discussion, I still haven't seen anyone
> mention their own personal observations of Scrub-Jays in northern Nevada.
> Experience from southern Nevada near Death Valley is of course very
> relevant for ID discussions, but doesn't help much on the question of
> distribution in northern NV. My suggestion is that if Oregon birders are
> interested in helping to resolve this question, it could be helpful to
> spend some time searching for scrub-jays in the areas that I mentioned as
> most likely to be productive: Namely, the southern and western parts of
> Sheldon NWR, and the Santa Rosa Mountains near McDermitt.
>
> Regarding the distribution of single-leaf pinyon in northern Nevada, I
> wouldn't question Tim's expertise as a botanist, regarding the present-day
> distribution. However, Lanner (1981) showed the recent historic range as
> extending north of Pyramid Lake in the west, and curving north toward the
> Idaho line in the Elko area. Lanner documented the extensive deforestation
> of pinyon-juniper woodlands in northern Nevada during the mid- to-late
> 1800s. Among other incidents, he noted that, "as early as 1860, Paiutes
> gathered at Pyramid Lake to decide how to cope with the white men who were
> encroaching on their lands ... and cutting down what the settlers
> derisively referred to as the Indians' [nut] 'orchards.'" As Lars notes,
> there is also evidence that pinyon was found much farther north in the
> early post-glacial period.
>
> Turning to the question of speciation/specialization raised by Jerry
> Tangren: Even if the bill morphology reflects an adaptation in Woodhouse's
> to exploit pine nuts, this doesn't necessarily mean a dependency. The
> relatively recent southward contraction of the range for single-leaf pinyon
> wouldn't automatically cause Woodhouse's Jays to disappear from the
> northern Great Basin, at least if and until some other species turned up
> and began to displace them through competition and/or genetic flow.
>
> --
> Joel Geier
> Camp Adair area north of Corvallis
>

 
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