While outdoor enthusiasts, those with yardwork to do, Zane at the Bradbury Mountain Spring Hawkwatch, and many others bemoaned the coastal storm that made for inclement weather from Tuesday through Friday morning, birders from the Mid-Atlantic to Nova Scotia were gearing up.

With the large (if not overall strong) area of low pressure riding up the Atlantic seaboard in late April when numerous species are now on the move, “Rarity Fever” symptoms were reported widely. As if recent “Megas” like Vermillion Flycatcher and Fieldfare here in Maine weren’t enough to stoke the fire, friends in Cape May began posting their “wish list” of possibilities. Storms such as these, sometimes called “slingshot” events can deposit birds further north than usual, facilitate the arrival of record-early migrants, and perhaps produce some astounding vagrant.

This far north, I simply had daydreams of southern “overshoots” that occur in most years – but especially following such storm systems – such as Blue Grosbeak, Summer Tanager, and Hooded Warbler. But I also started thinking about things from further afield like Swainson’s Warbler, all sorts of terns, and maybe even something from even further away like a South American Fork-tailed Flycatcher who overshot its goal and then got caught up in the system. Maybe a Magnificent Frigatebird? Or perhaps something else on one of my predictions lists for next birds for Maine, and myself.

While weather isn’t truly the ultimate cause of many vagrants, it certainly facilities their arrival in far-flung places. And weather can certainly impact migrants and displace them slightly further afield than they usually range. And storms like this, moving out of the Bahamas, strengthening in the South Atlantic Bight, and marching up the coast has quite a history of producing some great birding. (I wrote more in depth about some of these factors and causes of vagrancy in Chapter 4 of my first book, How to Be a Better Birder).

Here are the wind maps and surface maps from Tuesday through Thursday.

So, I cleared my schedule, kept an eye on the listserves to our south during the rain on Wednesday, and hit the field on Thursday, starting at Biddeford Pool. A few years ago, one similar (but stronger) storm system yielded a Summer Tanager, Blue Grosbeak, and Hooded Warbler in the neighborhood, and I had similar hopes for this morning.

I got really excited when one of the first birds I saw was a Magnolia Warbler (very early, perhaps by as much as 10-14 days!). Surprisingly, it was the ONLY warbler I saw all morning, and its early arrival is undoubtedly related to the storm. My first House Wrens were right about on schedule, however, and my first Veery was only marginally early.

However, in the same yard on Third Street, and loosely associating with said Veery, was not a bird I expected at all! In fact, I have a rule that I like to instill on my birdwalk participants: if it’s April in Maine and you see a dark-spotted Catharus thrush, it IS a Hermit Thrush. This was the exception to the rule.

There’s no doubt it was either a Gray-cheeked or a Bicknell’s Thrush, but those birds can be very challenging to ID. Generally very secretive in migration, getting good looks – let alone good photos – is often impossible. And neither is expected to be walking around front yards in a neighborhood!

It is also incredibly early, as neither of these species is usually detected in Maine (if at all, especially Gray-cheeked) until the third week of May, and sometimes not until even later. This was beyond early, and certainly suggests its arrival here was at least partially influenced by the storm system.

The overall cool gray appearance without any hints of reddish-brown anywhere (no matter what light angle I viewed it in) immediately suggested Gray-cheeked Thrush, but the date and circumstances warranted careful study. I even posted the photos online, sent them directly to friends, and added them to at least one forum, hoping for additional feedback.

However, other than the seemingly “dumpy” shape of the bird, nothing here suggests Bicknell’s Thrush to me. There’s just nothing warm anywhere in this bird’s plumage, and the cheeks are finally streaked gray, not more even washed warmish-brown as in most Bicknell’s. There’s no contrast within the wings, or especially between the uppertail and the rump, either.

Although this bird’s bill is fairly extensively pale, it isn’t as bright yellow as many Bicknell’s – although I can admit to not really being a fan of this fieldmark – and even has a hint of pinkish.

In other words, as several commenters mentioned, this really looks like a “classic” Gray-cheeked Thrush, with perhaps the appearance of a smaller size and more compact shape suggestive of the subspecies minimus that breeds mostly in Newfoundland and Labrador (it’s also the subspecies whose breeding range makes the most geographical sense to appear in Maine in spring). Of course, without measurements or vocalizations, there is still a little tinge of doubt in coming to a conclusive identification.

Now, a Bicknell’s Thrush, wintering somewhere in the northern West Indies or perhaps Cuba, beginning its trek to the mountains of the northeast, could have been entrained or “slingshot” by this storm. In fact, it would make a lot of sense. But Gray-cheeked Thrushes winter mainly in northern South America, and head north through Central America. That route would not seem to be effected by this storm. Perhaps it’s just a coincidence, and the storm was only a proximate cause of its arrival in Biddeford Pool.

Anyway, elsewhere in Maine, a White-eyed Vireo was in Cape Elizabeth (present through Friday) and a Summer Tanager was reported in Southwest Harbor. Early migrants included a Scarlet Tanager in Ogunquit and one found deceased in Cape Elizabeth, along with a few scattered Indigo Buntings as far inland as North Yarmouth.

Meanwhile, to our south, birders in Cape May had a White Ibis (and, even more excitingly, a –our!? – Little Egret, a first state record that may not have anything to do with the storm); a Red Phalarope and a smattering of birds just beyond their normal range, such as Summer Tanager, were in Manhattan, and a Kentucky and Yellow-throated Warbler were on Cape Cod among some of the widespread reports of “early” migrant arrivals.

During the day on Thursday, the low pressure system continued to weaken and dissipate over the Gulf of Maine, with a snotty easterly and drizzly onshore flow continuing. A weak, slow-moving cold front finally cleared things out mid-day on Friday.

In the dense fog on Bailey Island in Harpswell early Friday morning, I found pockets of migrants (mostly Yellow-rumped Warblers and White-throated Sparrows) but also several surprises, led by 1 male Hooded Warbler and a White-eyed Vireo, both along Elden Point Road – the kind of southern “overshoots” we have come to expect here in Maine from these type of storms.

There were quite a few other migrants around, as well. A total of 9 Blue-headed Vireos included a flock of 6 together, and there were scattered other migrants such as Ruby-crowned Kinglets, Hermit Thrushes, and Savannah Sparrows.

An early Yellow Warbler was also present, as were marginally-early (based on the current progress of the season) included 1 Common Yellowthroat and 1 Great-crested Flycatcher, while other personal FOY’s included more on-time Black-and-white Warbler (7) and Ovenbird (1-2). 11 Palm Warblers were my seventh species of warbler on the morning (plus Pine Warblers singing at home).

Elsewhere, another Hooded Warbler was found at Timber Point in Biddeford, and smattering of other early migrants included a Warbling Vireo on the Eastern Promenade (where a goodly number of birds were reported in the fog this morning)

I can only imagine what might have been found if every peninsula and island was covered over the past few days! So, with more birders hitting the field this weekend, and more people home from work to check on their feeders, I wonder what will be found. Maybe a Painted Bunting at a feeder? A Purple Gallinule in a marsh? But you know what I would like the most? A Swallow-tailed Kite over Bradbury Mountain during my hawkwatch workshop as part of the annual Feathers Over Freeport events!

Reference:
Clement, Peter. 2000. Thrushes. Princeton University Press: Princeton, NJ.