Last week, the Cape experienced a phenomenon strangely rare on a peninsula known for its bird migrations. A genuine “fallout” of migrating songbirds began partway through the day on Thursday and continued through the afternoon and beyond. Typical of a fallout, birds were in places they shouldn’t be and in numbers rarely, if ever, recorded. Shy woodland birds were alighting on offshore boats - and the people in them - and hopping around on beaches. This fallout gave us a window into just how difficult migration can be for birds, who may end up exhausted, disoriented, and stuck over water, where quickly finding a place to land could mean life or death.
Songbird migration is typically invisible for us – it happens while we sleep, then we birders wake up to see if the night brought us anything new. On calm nights with heavy movement, you might hear a few birds calling as they fly over, but you don’t see them or what they are going through – and most just keep going. But on Thursday, if you were on a boat or a bayside beach, you had a good chance of having a Palm Warbler perch on your hand, or a confused kinglet try to land on your head, as happened to me. At one point a junco hopped past my foot as it made its way down the wrack line like a sandpiper. I watched Hermit Thrushes come in off the water, through the pea soup fog, and drop into the dunes.
The species involved in this fallout were not the flashy types we see in May. Hermit Thrush, Golden-crowned Kinglet, Dark-eyed Junco, and Norther Flicker are all species you can find here in winter. They are short distance migrants who migrate in April, but mostly unnoticed away from a migrant trap like the Beech Forest in Provincetown, where you might see an uptick in those species on certain days. But over the course of Thursday, the numbers of these species at the Beech Forest went from almost none to record totals – by that evening, birders were reporting well over a hundred kinglets, and two days later numbers were up over 220, a record total for one location on Cape Cod. Other long-time birders noted more Hermit Thrushes than they had ever seen near Grays Beach in Yarmouth on Friday.
This event showcased darker aspects of migration we don’t often get to see – the exhaustion, desperation, and death that comes with this riskiest of avian endeavors. For mysterious reasons, it was mainly Northern Flickers, those big colorful woodpeckers of suburban lawns - the ones people love until they start hammering on your chimney cap at 6:30 a.m. – who paid the ultimate price in this fallout event. I received several reports of dozens, or more, dead on beaches from Wellfleet to Provincetown for several days after the fallout. I’m still getting those reports as new beach walkers discover the carnage for themselves.
But why mostly flickers, who weren’t among the most numerous species in the fallout? Maybe they floated better than the smaller birds, washing up while other species sank. Or maybe they were just easier to see on the beaches – kinglets are barely over three inches long and easy for the average person to overlook.
Whatever the reason, this kind of mortality is part of the deal for migrating birds – bad weather and exhaustion conspire to kill more birds than we can know, and this is built into their natural population dynamics. The problem these days is that we add to this natural mortality with unnatural mortality from window strikes, collisions with tall, brightly lit buildings, and outdoor cats, all of which kill billions of birds annually, most of which is preventable.
It was definitely exciting to see migration in action, and get up close and personal with some normally shy birds. But given the grim downside to this sort of fallout event, many of us would prefer regular old migration, where you hope to catch a few of these species at your local birding spot, alive and well. It turns out many of us were unprepared to deal with the fallout from a fallout.
