Date: 7/22/19 6:55 pm
From: Jeff Gilligan <jeffgilligan10...>
Subject: [obol] Re: Jewett's titmouse from Harney County
Great information Joel. That makes sense to me.

Jeff Gilligan


> On Jul 22, 2019, at 5:45 AM, <clearwater...> wrote:
>
> Lars Norgren's mention of a titmouse specimen from southern Harney County piqued my interest.
>
> According to Gabrielson & Jewett's "Birds of the Pacific Northwest" (1948), the specimen (then called "Gray Titmouse") was collected by Jewett in Blitzen Canyon in 1932.
>
> As Lars notes, juniper woodlands have been expanding in the decades since then. However my impression is that Juniper Titmouse is dependent on older juniper, so is absent from most of these younger stands.
>
> The Nevada silver mining boom of the late 19th century had a dramatic effect on the distribution of juniper (and pinyon) woodlands. For hundreds of miles around the main mining districts, Nevada was deforested as older trees were logged for use as timbers underground, while trees of all ages were logged and roasted in kilns to produce charcoal, to be used in smelting. A good account of the impacts can be found in "The Piñon Pine: A Natural and Cultural History” by Ronald M. Lanner (University of Nevada Press, 1981).
>
> It seems likely that such extensive logging of juniper woodlands would have fragmented the distribution of Juniper Titmouse, and perhaps also Woodhouse's Jay, resulting in isolation of outlying populations. Rather than representing a "failed range expansion," the Harney County specimens of these species gathered by Jewett and Gabrielson may have been part of small, relict populations in the latter stage of a range contraction, analogous to the small populations of "Streaked" Horned Larks and "Oregon" Vesper Sparrow that tenuously persist in the south Puget Sound region.
>
> Joel
>
> > Subject: [obol] Re: Woodhouse Scrub- jay
> >
> > There were pictures posted on Obol of some of the cabinet specimens. I don't recall the verdict, or who opined. I believe there are feather-based DNA tests that would reduce the debate. While it seems curious that no further detections have occurred in southern Harney County in the ensuing century, G&J collected a titmouse in that vicinity as well. Despite a growing extent of juniper and exponential increase in birder effort there have been no additional titmice reports.
>
> --
> Joel Geier
> Camp Adair area north of Corvallis


 
Join us on Facebook!