Date: 10/30/20 3:00 pm
From: Joel Geier <clearwater...>
Subject: [obol] Re: Woodhouse vs. California Scrub Jays an eBird suggestion
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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