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Birding in the digital age, chasing a modern day lifer.

view from on high

View from on high

As a frequent business traveler, I combine birding and business travel regularly and over the years I’ve visited many areas of the US at varying times of the years. So much in fact, that as each successive year passes I find my memories of individual trips often blend together. Often, while holed up for the evening in one hotel or another, I’ll fast forward to an upcoming trip to refresh my memory of speakers, events and of course seasonal bird distribution. Recently, I decided to look to see what bird species will be around for the upcoming ABA rally in San Diego. I’ve birded San Diego annually over the past nine years, but mostly in late winter and early spring so I wasn’t sure what to expect during early October. I went to eBird and pulled up a bar chart for San Diego county and was reviewing the list when I found an unexpected surprise, “Sagebrush Sparrow” and “Bell’s Sparrow”!

Had I been under a rock?!?… had these been split and I’d missed it? I was well aware of sub-specific variations in Sage Sparrow and have heard murmurings and conjecture of pending splits for years. However, if I had a dollar for each time I’d heard rumors like this… “Large-billed” Sparrow, Light-footed Clapper Rail, Crossbills, birders were always speculating about these things. “The white-eyed, Florida, subspecies of Eastern Towhee is not only morphologically different, but has unique song and calls as well. It’s a likely candidate for a split”, and similar commentary are regular topics of conversation at the bird festivals and on field trips.

In this case though, I was no longer dealing with conjecture as eBird was clearly treating these two former subspecies separately. Something had changed and I’d missed it. So armed with two new bird names, I began my search for a new life bird. Unlike typical searches for life birds though, this one would not require optics or even a strenuous hike. It would happen from the comfort of a computer chair.

Anza Borrego – dry lake basin

Anza Borrego – dry lake basin

Step 1 – locate & confirm the announcement.

I immediately typed “aba.org” and instinctively scrolled down the left side of the page to the “ABA Checklist” link. Hmmmm… the latest PDF (Version 7.4 – December 2012) listed only “Sage Sparrow”. Undeterred, I used the “Good Search” function at top center to search the entire ABA website for “Bell’s Sparrow” but found nothing. I then changed my search parameters and now checked the entire web. Cornell’s “All About Birds” still listed only Sage Sparrow, and a Wikipedia link offered chatter describing uncertainty over treatment of three listed subspecies (implying a split but not clarifying). It seemed certain this was a recent development, so I turned to the blogosphere where news is a bit more current. I amended my search again “ABA blog, Bell’s Sparrow”. There it was, a post from August 3rd, 2013 confirming the announcement of the new AOU checklist and split of the Sage Sparrow.

Step 2 – confirm my sightings.

Step 1 had proven more difficult than I’d expected but it would still pale in comparison to the next step. The limited online information had suggested that the Sagebrush Sparrow occurred along the eastern edge of the former Sage Sparrow range. I’d seen my first Sage Sparrows during the breeding season in Colorado and these would absolutely be the new species, Sagebrush Sparrow (Artemisiospiza nevadensis). So I dutifully updated my life list and simply added the word “brush” after Sage and changed the scientific name to my listed lifer. Bell’s would not be as easy though.

Anza Borrego desert 0207 flick

Clark Dry Lake Bed, Anza Borrego SP, CA

 

 

The Bell’s Sparrow complex was made up of two supspecies the dark pacific coastal subspecies Artemisiospiza belli belli and the paler A.b. canescens which was intermediate between coastal Bell’s Sparrow and Sagebrush Sparrows and breeding in the areas between the two. I had no recollection of seeing any of the more easily separable coastal birds on past adventures, but did remember seeing dozens of Sage Sparrows as I hiked endlessly through the Clark Dry Lake bed in Anza Borrego State Park years earlier looking for my first Le Conte’s Thrasher. In one of the very few summarized papers I’d found online, I’d seen a map showing ranges of the three subspecies. If I were to believe this map it seemed that the dark coastal form of Bell’s (A.b. belli) could reach well inland in San Diego county and that these birds could breed here. Further commentary on the Calbirds listserve further suggested though that A.b.canescens was wholly non-migratory, but as with any recent split I always tend to not take any of the early arguments as gospel. It is a certainty that much more will be learned over the coming years.

LETH 020707_02 flick

Le Conte’s Thrasher – Anza Borrego, CA

 

My only hope here was to find my digital photos from that day and hope I had kept some of the Sage Sparrow images, which were admittedly not wonderful. Luckily, this trip was punctuated by two memorable events that (at the time) were more notable to me than simply seeing a bunch of Sage Sparrows. The first was spotting and digiscoping my life Le Conte’s Thrasher, and then later spotting my first Kit Fox and photo documenting it again through the scope. Sandwiched between these two events was fun with Sage Sparrows. So, I turned to my “official” North American life list and scrolled past chickadees, wrens, thrushes until finding, “Le Conte’s Thrasher Toxostoma lecontei  – 2/7/07 Anza Borrego, CA”.

Kit Fox 020707_01 flick

Kit Fox digiscoped through Leica APO Televid 77 in Anza Borrego State Park 2/7/07

 

I’ve had 2 computers since 2007, so if the original images still existed, they would reside in one of three external hard drives. I checked the first one and opened the “Images” folder. Scrolling through year by year, and month by month… 2004, 2005, 2006, 2007… but nothing from February. Since this was a trip for the San Diego Bird Festival I checked for alternate naming. Continuing to scroll through the folders a finger swipe at a time, I found “San Diego Bird Fest 05” but nothing from 2007 until a few finger swipes more. The folder was named “SD Bird Fest 2007”.

ACWO ad 020707_01 flick

Acorn Woodpecker, digiscoped Cuyamaca Mtns, CA

Upon opening the folder I was instantly transported back to a great day of birding starting with Western Bluebirds, Acorn & Nuttall’s Woodpeckers, Oak Titmouse, Mountain Chickadees, & Pygmy Nuthatches in the Cuyamaca Mountains, and eventually changing to more common “desert fare” like Black-throated Sparrow, Costa’s Hummingbird, Le Conte’s Thrasher as I moved west into Anza Borrego. As hoped here were 3 less-than-great images showing 2 individual “Sage Sparrows” (we saw dozens but I only captured images of a couple).

BTSP 020707_02 flick

digiscoped Black-throated Sparrow, Anza Borrego, CA 2/07

 

A quick view of my slides allowed me to easily eliminate the darker coastal subspecies of Bell’s Sparrow A. b. belli, based on the lightness of the head & back and by the less pronounced malar stripe. Again some local CA birders had suggested that A .b. canescens is wholly sedentary, and if I were to believe them that would mean these birds could only be more Sagebrush Sparrows. However, it’s always been in my nature to question authority, so I remained dubious and went back to analyzing the photos. The best review on visual separation of A.b. canescens & A. nevadensis I found was a paper by Peter Pyle linked on David Sibley’s blog. Pyle summarizes the range of variation from palest to darkest of each by comparing a series of skins collected in fresh fall plumage (Sept.) and worn spring plumage (May).

http://www.sibleyguides.com/wp-content/uploads/On-separating-Sagebrush-and-Bells-Sparrows.pdf

L1050140

Bell’s Sparrow? – Anza Borrego State Park, CA 2/7/07

 

In my images, at least one of the birds looks most like the paler “Interior California” form of Bell’s Sparrow (A. b. canescens), while the other looks more like a Sagebrush Sparrow to me. If correct, this would be interesting as this would provide evidence of both species occurring together here in winter. The bird on the ground, shows no obvious back streaks and shows a comparatively strong malar stipe. What do you think? From Pyle et al. it seems, the extent of malar streak on this bird is outside the range of variation for Sagebrush Sparrow which should show more pronounced back streaking as well. Of course others suggest on the forums that canescens form of Bell’s Sparrow shouldn’t occur here either so…

L1050146

2nd “Sage Sparrow” still with strong malar but stronger back streaking

It’s a fun exercise from a listing standpoint, but more importantly, reviews of old photos like these may be helpful in shaping our growing knowledge base of the two species. Also, since  there is still a possibility that the Bell’s Sparrow group could be split into 2 separate species again, better understanding of these ranges will be of great importance in shortening our learning curve here. Please feel free to comment, and we can all learn more together!

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