Is there a bird in Massachusetts so obscure that even the bird guy hasn’t heard of it? No – don’t be ridiculous. But there is a species that nests on the Cape and Islands that is so rare, so poorly understood, and so mysterious in its habits that even ornithologists don’t know what their status is. And a tantalizing recent sighting, or, more correctly, “hearing” of this species has me wondering whether there may be more around than we realize.
The Leach’s Storm-Petrel is a smoky-brown, pigeon-sized seabird that nests in burrows on North Atlantic and Pacific Islands. They cover vast areas of ocean on long, pointed wings, detecting productive feeding areas with their super sensitive noses. Apparently the population is estimated at over 8 million pairs, which makes this bird you’ve never seen or heard of almost 3,000 times more abundant than the Piping Plover, globally.
Here in Massachusetts, where they are listed as Endangered with less than 15 pairs estimated to breed, they are known to nest mainly in the crevices of an old rock wall on one of the Elizabeth Islands. But when a field ornithologist who had studied nesting Leach’s Storm-Petrels in Maine heard a familiar, crazy sound on Monomoy one recent night, it raised the question of another breeding location.
I’m obligated to tell you that an alternative name for the Leach’s Storm-Petrel is Mother Carey’s Chicken, as every source insists on mentioning, even though nobody has likely used this name in over a century. But the etymology is fun and worth mentioning – Mother Carey was an old sailor’s personification of a cruel and angry sea, and storm-petrels, also thought to be the souls of dead seamen, were “Mother Carey’s Chickens”. Indeed some petrels prefer a wind-churned ocean to help them fly, and so can be most common in the kinds of seas no sailor wants to see.
When you factor in their nocturnal nesting habits, bizarre calls, and tendency to be seen fluttering around alone hundreds of miles from land, the air of mystery around these birds thickens. Imagining trying to study a bird that waits for cover of night to disappear into an underground burrow, cackles maniacally from the darkness, then leaves before day break to dissolve into the vastness of the oceans.
They live a long time, so need only raise one chick per year. These only children look like large, subterranean dust bunnies. They grow morbidly obese on an oily diet of regurgitated zooplankton, squid, and small fish before eventually slimming down to their flying weight. They take up to a few months to fledge and head out to sea, apparently not returning to land for up to five years.
Around here, your best chance of seeing a Leach’s Storm-Petrel is to be at Sandy Neck in Barnstable or First Encounter Beach in Eastham during September and October storms. This is when northeast, then northwest winds blow them in from the Gulf of Maine and concentrate them along the shoreline while they find their way out of the bay.
But might they be breeding on Monomoy? Who knows – I suspect this was maybe a prospecting single bird rather than evidence of a breeding colony. The sandy dune soil on much of the refuge might be difficult for burrowing, as tunnels could easily collapse, and predators could easily find and dig into their super smelly burrows. But given their tendency to nest in rock walls and old foundations, they could be nesting just about anywhere near the coast, I suppose. So keep an ear out for a crazy cackle or a chilling purr around your coastal cottage some still night, as Mother Cary’s Chickens may have come home to roost.