Late October through early November is traditionally the best “rarity season” in Maine, where vagrants from all directions are hoped for, and even expected. We’ve been in a rather active and dynamic weather pattern of late, and this may help to usher vagrants in our direction. While weather rarely “blows” birds off-course, winds and weather systems can certainly facilitate their arrival in far-flung places, especially when combined with some sort of misorientation (for a thorough discussion of the concept, see Chapter 7 of my book, How to Be a Better Birder).
As October progresses, the nights get longer, and the days (usually) get colder. The growing season comes to an end (although in many spots the killing frost has not yet reached the immediate coastline yet this year), and food sources become greatly limited. This can push vagrants that may have arrived over the course of the fall migration into favorable micro-climates and patches of seasonal food abundance. More recently-deposited vagrants, “late/lingering” migrants, and other more typical species can also concentrate in such prime areas, such as urban parks, coastal migrant traps, and so on.
Let’s take a look at some of the recent weather, and attempt to identify some possible species to consider.
Strong southerly winds pumped warm air into the area from the Deep South and the Bahamas (and the South Atlantic Bight). These are favorable conditions for depositing “180-degree misoriented migrants” from the south, such as Summer Tanagers and White-eyed Vireos. I wonder if it’s a little too late for a big push of southern birds, however, as many of the Neotropical migrants have already departed the continent. Meanwhile, that extensive southerly flow all of the way into Mexico is the type of weather pattern that can facilitate the arrival of long-distance vagrants, such as Fork-tailed Flycatcher.
Sparrows are on the move now, and northerly winds with cloudy skies overnight on 10/18 to 19 resulted in a big push of sparrows. The low ceiling likely resulted in disorientation of these low-flying migrants by the big city lights, resulting in a massive flight of birds in Portland’s East End on the morning of the 19th. I estimated over 2000 White-throated Sparrows and 500 Song Sparrows just on the Eastern Promenade alone, with dozens more in almost every lot I checked. A hundred White-throats were in the North St Community Garden, and by the end of the morning, I had tallied 8 species of sparrows, and impressive numbers of Chipping Sparrows (76) and Eastern Phoebes (15) among others. Although 2 Red-bellied Woodpeckers were my 175th species on my Eastern Promenade Patch List, I was surprised that I could not tease out any rarities from the volumes of birds (the sheer number of birds plus gusty winds hampered detection, no doubt).
By 10/19, a strong cold front – a rare occurrence this season – pushed through, and with it, a huge flight of migrants. I tallied over 1100 birds at Sandy Point on the morning of the 20th, led by 461 Yellow-rumped Warblers and 159 American Robins.
Rain began to arrive in the afternoon of the 21st, and it didn’t let up until this morning. This massive coastal Nor’easter drenched Maine with up to 5” of rain, and moderate to strong northeasterly winds battered the state, especially the coast.
Birding was a challenge on Wednesday and Thursday, as strong winds and often-heavy rain made things difficult. Rain and coastal fog and mist precluded seawatching, and any lake-watching for grounded waterfowl was rendered impossible by visibility and waves. Essentially, feeder-watching was the best bet these two days, and a growing contingent of sparrows at both our home and here at the store provided the entertainment. About 200 Common Grackles descended into our Pownal yard on the 23rd as well.
And I had a great day of birding in Cape Elizabeth. I began with some seawatching at Dyer Point. From 7:50 to 9:50, I had moderate to good visibility for all but a total of 47 minutes as light showers and mist rolled through. Seas were down to 4-6 feet, and moderate north winds continued. Here’s the scorecard (all southbound unless otherwise noted) – which was actually a little lighter than I had expected:
317 Double-crested Cormorants
127 Northern Gannets (about evenly split between north and southbound)
77 Common Eiders (several hundred northbound)
20 White-winged Scoters
18 Black Scoters
17 Red-breasted Mergansers
16 unidentified ducks
16 Common Loons (plus 18 northbound)
15 Surf Scoters
10 “dark-winged” scoters
8 Long-tailed Ducks (first of fall)
8 Red-throated Loons
5 Great Blue Herons
5 Bonaparte’s Gulls
3 Red-necked Grebes
2 Green-winged Teal
2 Great Cormorants
2 Laughing Gulls
1 Black Guillemot
1 Peregrine Falcon
1 White-throated Sparrow (flew in off the water at 8:05am).
Next up was Kettle Cove, where a nice diversity of migrants, especially sparrows, also included an Orange-crowned Warbler and 3 Common Yellowthroats. Even more interesting was this gull, which appears to be a hybrid Herring x Great Black-back. Intermediate in size and shape between the two, and with an intermediate mantle color, the short wings and pinkish legs separate it from Lesser Black-backed.
A local sparrow-rific patch of private property was fruitful as well. Although a very tardy Bobolink was the only surprise here, plentiful numbers of sparrows included 200+ White-throated, 100+ Song, 50+ Swamp, 50+ Savannah, 50+ Dark-eyed Juncos, at least 10 White-crowned Sparrows, and a single Lincoln’s Sparrow. A Red-bellied Woodpecker and my second Carolina Wren of the morning were added to the tally.
A male Black-throated Blue and a female Black-and-white Warbler joined Palm and Yellow-rumped Warblers feasting on seaweed flies in and near the wrack at Pond Cove, where another Red-bellied Woodpecker was sounding off.
On my way back, I swung through the goose fields, and clearly more Canada Geese have arrived in the last few days. 718 was a new season-to-date high count, with the most interesting new arrival being this spiffy leucistic Canada. Unlike a hybrid with a Snow or a Domestic Goose, this neat bird was the same shape and size as the average Canada, but with a dull brownish cast to the head, neck, and wingtips.
As this nasty low rides up into Atlantic Canada and beyond, strong wrap-around winds will offer the potential to displace Northern Wheatears or rare geese from Greenland. Meanwhile, next week, we’ll see unseasonable warmth return on southwesterly winds (“vagrant winds” as I like to call them), just the type of scenario that can facilitate the arrival of strays from the southwest, such as Cave Swallows and Ash-throated Flycatchers. They will also facilitate the survival for at least a little longer of vagrants that are still present but as so far gone undetected.
There isn’t one predominate pattern that yields a strong suggestion of any particular vagrant (or group of vagrants) from any particular direction. However, it is clear that we are getting a nice sample of different conditions that could produce some fun stuff.
At the very least, I expect some big flights of migrants, both day and night in the coming days. In fact, I think there will be a big one tonight. Check out these northwesterly winds that should be ushering in a big push of birds:
Sparrows will make up the bulk of the flight, especially White-throated Sparrows and Dark-eyed Juncos. If the clouds clear by dawn, I might get a big push at Sandy Point. If the ceiling stays low overnight, look for concentrations of sparrows in migrant traps, especially in and around bright cities. Meanwhile, during the day, a lovely weather forecast should get plenty of birders out into the field.
Needless to say, I will be out looking, and I hope you will to! I look forward to what the coming days and weeks will bring.