Firsts and Slingshot Birds
Early spring is a time of many firsts for the nature watcher. Sometimes slowly, sometimes in bursts, locally slumbering critters are coming online every day. Many of us heard our first spring peepers this past week, a welcome auditory sign of spring. On Saturday alone, when a happy coincidence of good weather and a day-off allowed me to leave my house, I racked up my first butterflies (mourning cloak and cabbage white), first wood frogs, first snake (garter snake), and first significant patch of blooming flowers (a lovely lawn weed called bird’s-eye-speedwell). Sunday night, my three-year-old son and I ventured forth to see my first of spring—and his first ever—Spotted Salamanders at a trusty spot, where we got several out of harm’s way from passing cars.
Birders even have a special, cryptic code for the first sighting of the year for a particular species – FOY, for First of Year. Many are reporting their FOY woodcocks, phoebes, Ospreys, and other species right now. Sometimes the FOY doesn’t make a lot of sense, like when a birder in Harwich noticed an absurdly yellow bird livening up her feeders on Monday. It turned out to be a FOY Prothonotary Warbler, a bird of southern swamps that should theoretically never occur this far north. What is it doing here in March? Well, it got caught in the “slingshot”.
A “slingshot” migration event occurs when multiple weather events conspire to trap northbound migrating birds off the southeast coast, forcing them to fly north until the winds allow them to orient back to land, often far north of their intended destination. Here in New England we would perceive these conditions as a warm front followed by a cold front, like what happened this past weekend. The result is that birds who were trying to get to say, the Carolinas, end up in Nova Scotia, or, much to our pleasure, Cape Cod.
Like some birders version of a trick pool shot, Marshall Iliff of Cornell’s eBird project called this one. He was birding at Gooseberry Neck in Westport early Friday morning when he found a couple of newly arrived migrants, a Louisiana Waterthrush and a Yellow-crowned Night-Heron, a month earlier than expected. He quickly got word out that a “slingshot” migration event might be underway, and folks should be on the lookout for other early southern species, including Prothonotary Warbler. This was a bold prediction – there have only been three March records of this lovely bird ever in Massachusetts – but he was right.
This individual may have just traveled from a forest in Venezuela or Suriname, then across the Caribbean to Florida. From there, maybe it intended to hop up to the evocatively named Great Dismal Swamp in Virginia, where their song of simple, repeated notes can be the most common sound of spring. But the winds had other plans for this weary traveler.
The same goes for the eye-wideningly rare Swallow-tailed Kite reported from Provincetown on Monday. The world’s loveliest and most graceful hawk, these birds make black and white look better than your average Oscar tux. Swallow-tailed Kites are currently returning to Florida from South America, and occasionally get caught in these same weather traps.
I suspect these aren’t the only slingshot refugees here on the Cape and Islands right now, so be vigilant, and be prepared for the possibility of more, like early Indigo Buntings, Blue Grosbeaks, or Summer Tanagers, after the next warm front. The next warm front will be along—and I guarantee this—sometime between now and mid-July.