Date: 10/30/20 11:00 am From: Jerry Tangren <kloshewoods...> Subject: [obol] Re: California vs. Woodhouse's Scrub Jays in Oregon
Tim Manolis, who has extensive experience birding northeastern CA, feels that any Woodhouse eBird records north of Lake Tahoe are incorrect...
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From: <obol-bounce...> <obol-bounce...> on behalf of Joel Geier <clearwater...>
Sent: Friday, October 30, 2020 9:48:31 AM
To: Oregon Birders OnLine <obol...>
Subject: [obol] Re: California vs. Woodhouse's Scrub Jays in Oregon
Reading the OBOL digest this morning, I'm reminded of the old Buddhist parable of six gentlemen trying to describe an elephant based on limited data. In this version, the "elephant" is the distribution of Woodhouse's Jays in northern Nevada, and the gentlemen are our learned Oregon brethren, trying to describe the situation based on evidence from the other side of the state line.
Experience has been brought to bear from Steens Mountain (40 miles north of NV), Adel (15 miles north of the extreme NW corner of NV), and Picture Rock Pass (more than 100 miles to the NNW). Others have commented based on the bubbles that show up on eBird maps. Finally, Kevin mentioned the Blizzard Gap BBS route, which starts in nearly treeless sagebrush steppe about 4 miles north of NV, and angles WNW toward Adel.
While all of these may be relevant for the original topic (possible rare occurrence of Woodhouse's Scrub Jays in Oregon), extrapolation to make conjectures about the identity of Scrub-Jays reported in northern Nevada is unfounded.
In fact, reports of Scrub-Jays are very sparse in northwest Nevada, anywhere north of Winnemucca and west of the Independence/Tuscarora Mountains (north of Elko), at least until you get to the California line in the Ft. Bidwell/Cedarville area. So the lack of photographic documentation for the few bubbles that show up on the eBird maps is not surprising.
The two BBS routes in Sheldon NWR (an eponymous route and the Bald Peak route) each turned up WESJs just 6 times in 21 and 26 years of data, respectively, with a grand total of only 4 detections in the past 10 years, 2010-2019). In four years of data for the Sheldon NWR Christmas Bird Count, we have yet to see a single scrub jay.
The speculation that lots of birders have been carelessly twitching Woodhouse's based on geography is also unfounded. I've attached a table with ALL of the eBird reports of WOSJ that are within 50 miles of Oregon, sorted by latitude. Here I'll go through them in some detail:
There are just five reports from within 10 miles of the state line, in the Sheldon/Denio area. Just the two closest to Hwy 140 (one by a birder from the Klamath Basin, the other by a birder formerly from Central Oregon, last reported from the Farallons) *might* be cases where Woodhouse's was assumed to be the default -- perhaps we should ask them. Three are by Terry Rich who ran the Sheldon NWR BBS route for many years, and also the Blizzard Gap route in recent years. Terry has recorded several of his other detections from that route as unspecified "Western." I have his e-mail address so I'll ask him if he recalls why he recorded these three as WOSJ.
A little farther south and just over the line from Calif. near New Year Lake, George Chaniot gave a fairly detailed description of the one bird that he identified as a WOSJ.
The next closest report, in the Santa Rosa Mtns SE of McDermitt, was recorded by a Great Basin Bird Observatory (GBBO) field surveyor during a point count. Rob Lowry also recorded one in the Santa Rosas about 21 miles south of Oregon. Although Rob was doing a Nevada "big year" that year (I think he broke or tied the NV state listing record), this wasn't a species that he would have needed to pad his list. He compiles the Carson City CBC, in the contact zone between California and Woodhouse's Scrub-Jays, where hybrids are also possible.
GBBO surveyors also recorded several WOSJs at a couple of points just south of there, back in 2003-2005. I asked Jen Ballard of GBBO about these last year and she confirmed that their surveyors did find Woodhouse's in that area. As this was prior to the AOU/AOS species split, I'm not sure if they looked/listened closely to rule out hybrids (which would have been considered intergrades at that time).
There are only a few other eBird reports from the 30- to 52 mile range from Oregon. One fits into the Santa Rosa range cluster, another in the Jackson Mtns near Jungo was recorded by the head honchos at eBird, and the last one is from the south end of the Hays Canyon Range, just as close to Pyramid Lake as it is to Adel.
In summary, Oregon birders need not fret too much about the possibility that birders are just wildly and heedlessly twitching Woodhouse's Jays whenever they see a scrub jay in NW Nevada. Hopefully after a few more years of careful attention (which I know is being encouraged by the state/county eBird editors as well as by myself as regional CBC editor), we'll get more data points with careful descriptions, and perhaps even more photos to satisfy the folks who won't believe anything less than a photo or specimen.