Shearwaters and Whale Watches

Jul 31, 2019

Credit Mark Faherty

In this time of tourists, the whale watch business is in full swing. And with good reason – the Cape offers some of the world’s best whale watching, with our close proximity to the perennial whale feeding grounds of Stellwagen Bank. 

Whether you’re a weekly renter or a local, in terms of wildlife viewing, it’s hard to match the experience of being feet away from a seemingly mythological leviathan like a Humpback Whale, perhaps in the company of a calf, casually bubble feeding beside the boat. But there are some smaller residents of our offshore waters no less deserving of your attention, creatures that have come here from all corners of the globe to feed in our fish and zooplankton rich waters. Seabirds, mainly shearwaters, storm-petrels, terns, and gulls, are also worth watching along with the whales.

We have four shearwater species in this area, and it’s not unusual to see all of them on a whale watch. Learn their distinct flight style and you’ll be able to distinguish them from gulls at a great distance –moving in long glides interspersed with stiff-winged flaps, they hug the water, occasionally wheeling up and back if there’s wind. These ocean wanderers are brilliant at using wave-deflected wind to keep them aloft and propel them forward, thus saving valuable energy while they cover huge areas of the trackless ocean in search of productive feeding grounds.

Unlike the vast majority of birds, they use their nose to get around and find food. Shearwaters and other so-called “tubenoses”, like petrels and albatrosses, have special bill structures to concentrate scent over their sensitive noses. They can detect the faintest whiff of chemicals associated with the feeding of zooplankton, leading them across miles of featureless ocean to areas where squid and small fish are concentrated. At Stellwagen, sometimes they just have to look for the humpbacks. If the whales are feeding at the surface, look for shearwaters and other seabirds feeding right in the mouths of the whales, snatching the small fish known as the sand lance out of the air as they try to escape the belly of the beast.

In most years, Great Shearwater is the most likely of the group to turn up on a whale watch. A distinct dark cap with a white neck and thin white rump tells them from the others. Sooty Shearwaters, being all chocolate brown with pale underwings, are easy, and can be found in most of the world’s oceans. Big, lumbering Cory’s Shearwaters, arriving here from the Mediterranean and Eastern Atlantic, prefer warm water, and are increasingly common. They are uniformly grey brown above from beak to rump, sporting a big yellow bill. At the other end of the spectrum, tiny Manx Shearwaters flap the quickest, appearing all blackish above and white below. This is the only member of the group that has nested in Massachusetts, if very rarely. Swallow-like Wilson’s Storm-Petrels, all from nesting islands deep in the South Atlantic, patter along the surface among the other birds, all dangling feet and fluttery wings.

For the seasickness-averse among you, the good news is that we are in one of the few places in the world where shearwaters and storm-petrels can routinely be seen from land, especially off the backside of the Cape from Provincetown to Chatham. And if you are such a landlubber than even the beach makes you seasick, or if you just love cutting edge ornithological research, then you can follow a satellite tracked Great Shearwater courtesy of Stellwagen Bank marine sanctuary. The sanctuary named nine of this summer’s tagged birds after Mass Audubon sanctuaries, and you can follow the tracks of the bird named Wellfleet Bay, my personal favorite, on the Mass Audubon Wellfleet Bay social media pages. As for next week, you should tune in for news of a rare Caribbean stowaway on a recent whale watch trip out of Provincetown.