An grownup male indigo bunting. — Ken Magnuson
Autumn is usually the height season for Winery birding, as migrants stream south alongside the coast, making the most of ocean-moderated temperatures and resource-rich coastal thickets. Spring migration, in distinction, typically means simply the return of our breeding birds, with the occasional, unremarkable vagrant thrown in.
However some years, climate situations conspire to reverse the mannequin, turning our typical lackluster spring migrations into thrilling occasions. Generally a robust southwesterly blow follows a protracted interval of entrenched northerly winds, splashing a pulse of delayed migrants onto our shores. Different instances, the circulation of a coastal storm picks up songbirds within the Southeast and flings them our method over the open ocean.
In any case, the result’s hanging: The abrupt look of enormous numbers of migrants, typically together with “overshoots” — species that ought to not but have arrived at our latitude, and even species that shouldn’t happen this far north in any respect. Island birders go nuts.
Late April of this 12 months featured such an occasion. With my typical impeccable timing, I used to be touring abroad and missed your entire occasion. However the Island’s birding Fb group boiled over with experiences indicative of the very best spring birding in a few years. Ken Magnuson began issues off on April 21 by photographing a black-whiskered vireo, a Caribbean fowl by no means earlier than recorded north of the Carolinas, and the most effective birds ever discovered on the Winery. Different experiences of vagrants and overshoots quickly piled up: summer time and scarlet tanagers; blue and rose-breasted grosbeaks; yellow-throated, prothonotary, and hooded warblers; painted bunting; and extra.
As is common with overshoot occasions, a signature species of this fallout was the indigo bunting. Sparrow-size grownup males are stunningly lovely, a crystalline blue throughout. Females are mushy brown, practically featureless birds. Indigo buntings are straightforward to seek out right here throughout fall migration (primarily drab immatures, which resemble grownup females), and we get a couple of regular transients each spring. However for some purpose, indigo buntings additionally determine in each fallout, typically leading to a robust pulse of arrivals weeks earlier than migrants on their typical schedule arrive right here.
Regardless of this sample, indigo bunting was for years unknown as a breeding fowl on the Winery. I like Allan Keith’s rationalization: Arriving in early Could, when Winery vegetation could also be weeks behind that of mainland places in leafing out, migrant buntings take one go searching, say one thing impolite in regards to the Island’s bleakness, and transfer on to someplace that has leaves.
I believe it was in 2003 that issues modified. The Island noticed an enormous inflow of indigo buntings, maybe much more hanging than this April’s. I bear in mind the late, nice Vern Laux telling me of an up-Island area with 60 of them in it — even permitting for Lauxian hyperbole, clearly a startling sight on the Winery.
It was both that 12 months or the subsequent when this species was first confirmed breeding on the Winery — a pair, if I bear in mind appropriately, at Waskosim’s Rock Reservation in Chilmark. Stories of different singing males prompt different breeding websites. Clearly, some birds in that unique inflow remained right here to nest, they usually or their offspring continued return in subsequent years.
In 2005, indigo buntings first turned up on my Breeding Fowl Survey (BBS) route. Run yearly on behalf of the U.S. Geological Survey, this route consists of 50 mounted factors alongside a 25-mile route, winding from Lobsterville to the West Tisbury Highway, with every level the location of a three-minute fowl rely. You’ll be able to’t ensure you’ll discover each species that nests right here, however this protocol samples sufficient actual property to offer sense of our breeding birds and their relative abundance. (Or at the very least their relative detectability.)
For the subsequent few years, I recorded two or three indigo buntings every time I ran the route, suggesting that the species was a well-established, pretty widespread a part of our breeding avifauna. And every summer time, I’d encounter a half-dozen or so different breeding pairs (certainly solely a fraction of the Island’s precise inhabitants) at varied factors across the Island.
However in 2011, I didn’t file an indigo bunting on the BBS route, and whereas one pair of buntings hung in for a 12 months or two close to the Tashmoo Overlook, by 2015, the species was gone as a Winery breeder, so far as I may inform.
Till 2019? That, in fact, stays to be seen. However you may be positive I will likely be wanting. April’s fallout was the primary occasion in years that produced experiences of teams of indigo buntings, and Web experiences prompt that singletons of this species have been briefly downright straightforward to seek out on the Island. The sample mimics that of the early 2000s, elevating the chance essential mass of those birds has hit our shores.
No matter what occurs, the historical past of indigo buntings on the Winery highlights the dynamic nature of our fowl life. Some years we get hardly any; some years it rains buntings; some years they’re a standard breeder; some years they don’t breed in any respect. Issues all the time change, and it’s that easy undeniable fact that retains birders heading out the door.