It was a very good day up at the Bradbury Mountain Spring Hawkwatch, sponsored by Freeport Wild Bird Supply and Leica Sport Optics. The 2017 Official Counter, Zane Baker, had the day off today, so I was the counter for the first half of the day. Jeannette took the second shift, and were it not for Sasha’s declining health, I definitely would have remained until day’s end. We were having too much fun!

With light southwesterly winds aloft (and light and variable at the surface), record warmth, and perfect timing, we knew it was going to be a big day. Zane could not stay away, and Katrina Fenton, the 2012 through 2014 Official Counter, was visiting from New Hampshire. Several other local birders were present as well, as were hawkwatchers from New Hampshire and Mid-coast Maine. After a slow, somewhat chilly start, the day, and the hawkwatch began to heat up.

At approximately 11:10, I spotted a Black Vulture soaring over Hedgehog Mountain. It was low and relatively close, affording prolonged scope views for over five minutes before it drifted away to the north or northeast. Several personal first-of-years included 7 Northern Flickers, 1 Barn Swallow, and 3 Yellow-rumped Warblers. 2 Yellow-bellied Sapsuckers and 1 Ruby-crowned Kinglet were also first of the season for the count site.  We also had a steady trickle of migrant Tree Swallows, along with a smattering of other passerine migrants. Later in the day, two Sandhill Cranes (our 6^th and 7^th of the season) also passed overhead.

A steady light flow of raptors was adding up, too. 209 were tallied when I departed at 1:00, led by 59 American Kestrels and 37 Broad-winged Hawks, but a decent total of 11 species in all. (A goodly 361 was our final tally by day’s end).

Sure, we had a little rarity fever on our minds, especially after the Black Vulture (downright expected on such conditions in early to mid-April), but all hell broke loose at 12:18pm EDT. 

Then, a medium-small passerine came flying towards us, moderately high, and suggestive of an Eastern Bluebird with a thrush-like flight and shape. But as I lingered on it, I realized it was definitely not a bluebird – its flight was faster, steadier, and it was solidly colored. It also seemed a little larger and longer. It was backlit by the sun, it was coming right at me, but it was looking odd. 

As it got closer, I said “get on this passerine…Katrina, get your camera!” as she was closer to her long lens than I was to my superzoom. As it passed right overhead, still a little backlit, I yell, “TOWNSEND’S SOLITAIRE!”

A slim bodied, long-tailed, thrush-like bird passed overhead, with a screaming wide, bold, and buffy stripe through the near-center of the wing (obviously known to be the base of the flight feathers).

As it flew over, then headed straight away, it was finally getting into better light. And it looked gray. Quite gray. As I was calling for it to “turn, turn!” Katrina was unable to find it in the viewfinder, so switched to bins. Zane got on it, as did a couple of other birders, including Don Thompson.

Unfortunately, it did not turn, and I never saw the upperwing. I also never got a real handle on the tail, beyond silhouette.

I don’t think we had really clinched the ID yet, even though I knew it had to be a Townsend’s Solitaire. Only the Catharus thrushes share that wide and distinct buffy wing stripe, which I will address in the notes below.

I stepped aside, turning over the watch to Zane, and wrote two pages of field notes. Only then did I consult a Sibley, and I discussed the bird with others, especially Katrina who was the only other person it saw it fairly well in binoculars.

• Bold, buff wingstripe obvious, from based of inner secondaries to end, or nearly so, of outer primaries. Wide and fairly even throughout.
• With sun behind it, it first looked all-dark, with little to no contrast (actually thought of a blackbird at first), but got lighter as it passed roughly overhead, distinctly solid gray as it went straight away. But it was never in perfect light.
• First impression was of a thin tail, which it may have then partially opened at one point, but as it was going away, no detail was seen (i.e. overall color or white fringes).
• Only other possibility was a Catharus thrush, but that seems even less likely to be overhead at 12:18pm on April 11^th in Maine. While Hermit Thrushes are just now arriving, and we do occasionally see “morning redetermined migration” throughout the day (e.g. some Yellow-rumped and Palm Warblers, along with at least one surprisingly high Eastern Phoebe today), Catharus thrushes usually don’t reorient, and if they do (at least at Sandy Point in the fall), it’s immediately after sunrise.
• Question: could the back-lighting have made the wingstripe look wider and bolder from below? From my experience at Sandy Point, when in fact a Catharus does go overhead, that wingstripe is obvious, but it is not as obvious as in this bird. And of course, no lightening scenario would make a brown bird look cool gray.
• Tail seemed long, and the body especially seemed too slim for a Catharus. It did not have a broad chest or pot-bellied appearance, as it was uniformly more tubular (even slimmer than a bluebird). Smaller and much skinnier than a Wood Thrush, yet larger and longer than a Veery, we of course went to Hermit Thrush as a fallback (due to seasonal status; but see discussion below).
• Upperwing not seen. Tail pattern not deciphered.

Discussion:

– Katrina: “When I finally got on it (in bins; heading away but now in the best light we had it) it did not look brown at all, and definitely appeared gray.” Zane also thought it looked gray, not brown.

– Katrina thought the tail looked long, body slim and not pot-bellied like a Catharus. And she reviewed my notes with no additional comments or edits.

– We then consulted Sibley Guide to Eastern Birds (2^nd edition): Underwing coverts not obviously pale as in Hermit Thrush, wing pattern of solitaire only similar to Swainson’s or Gray-cheeked Thrush/Bicknell’s Thrush. Of course, what would one of those species be doing here now, and flying overhead in the middle of the day? Even if a vagrant/pioneering individual of one of those species wintered far north of usual range, why would it be in flight in the middle of the day? But Townsend’s Solitaires are on the move about now, and do migrate diurnally (like bluebirds).

The light was simply not perfect, and we were unable to get photos, so we carefully discussed the bird. With several birders of various levels of experience around us, we took this as a “teaching moment” to go through the process and exemplify the caution needed to make a call of a rarity under less than ideal circumstances.  But through the process of elimination, we simply cannot come to any alternative conclusions. It was too gray, too slim, and too out of place for a Catharus thrush; we could not figure out how the lighting or the view could have resulted in a solidly-gray undersides with little noticeable contrast (definitely no spots!). Also, I’ll fallback a bit on my initial excited call of Townsend’s Solitaire.

While we would have loved a longer and closer look in better light (or a brief alightment on a nearby tree!), and of course a photo, it is impossible for me to believe this was anything other than a Townsend’s Solitaire, a rare but regular vagrant to the Northeast. This was a new record for the Bradbury Mountain Spring Hawkwatch, and the park in general. And it might very well go down as the bird of the season.