Courting Waterfowl - Red-breasted Merganser

I finally got to the Massachusetts coast for a day of birding around Cape Ann. Highlight was definitely the courting Red-breasted Mergansers and Buffleheads. (Also saw some Common Goldeneyes, but they were at a distance.) Waterfowl do their pairing on wintering grounds, for the most part, but the girls seems finicky; I have seen it throughout the winter months. Nevertheless, fun to watch.

First the Red-breasted Mergansers, who occasionally seemed paired, but don't believe it. The boys are all busy boasting their prowess.

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Nest post in a couple of days with the Bufflehead antics. Good birding.

Cracking the Hard Shell

All along the coast, diving ducks are common during the winter: eiders, buffleheads, goldeneyes, scoters, mergansers, harlequins. They ride the waves, disappear beneath the surface, then pop back up like so many corks. Occasionally one comes to the surface with something in its bill, pauses a moment, swallows, then resumes doing its duck thing.

I watched a female Common Eider come to the surface with something that looked like a flattened egg. It was dark, appeared solid, and was about as wide and almost as long as her bill. Only later did I realize that she had brought a shellfish to the surface.

She was diving to find food. A favorite food for diving ducks is mussels, those two to three inch long, dark, oblong shellfish. They dive to the bottom, and rip the mussel, shell and all, from the colony. The eider I was watching brought to the surface an intact, tightly closed bivalve, something related to the mussel, but larger. I began to wonder: How did she get through the hard sea shell to the nutritious food on the inside?

A lot of food is protected by a hard outer shell. Plants and animals have developed defenses against those things which would eat them. The hungry foragers in turn have developed ways to breach the defenses.

Let’s take a look at our bird feeders. If you do much bird feeding, you know that sunflower seeds are favored by many, perhaps most, of our feeder birds. The edible and nutritious part of the sunflower is inside its small, hard shell. Have you ever tried to open a sunflower seed? Putting aside the fact that we are big and clumsy when it comes to handling something that small, it is nevertheless a very difficult task to break open the seed.

Many birds have no trouble. The grosbeaks and cardinals can perch on the sunflower feeder or stand on the platform and shell half a dozen sunflowers seeds in the time it takes me to write this sentence. They have powerful beaks to crack apart the hard casing. Many smaller birds are equally adept. The finches, for example, will fill the nine perches on the sunflower feeder and consume seed after seed, scattering the husks to the ground beneath them.

Not all of our feeder birds are as adept at opening the sunflower seeds. These birds have beaks more suited to gleaning insects along tree trunks, branches, or leaves. But they are opportunists, and our feeder food is handy. Chickadees and titmice carry the seed to a branch, hold it between their feet, and drill it open with their sharp beaks. The seeds do not yield the tasty meat easily. These small birds have to pound repeatedly before the shell cracks open. Nuthatches have a similar problem, but are not designed to hold the seed between their feed. They carry it to a tree trunk, jam it into a crack, and then pound it open.

As big and muscular as the Blue Jays appear to be, they also do not have a beak designed for opening seeds. I often see them carry a seed to a branch, hold it between their feet, and pound it open. The jays also have another way of dealing hard shelled seeds. They store them in their crop. I often see a jay’s throat swell as it scarfs seed after seed. The seeds which are stored in the crop get softened up in a kind of pre-digestive soaking.

There are a lot of different ways that birds have found to crack the hard shell of a nut. My favorite is the brainy solution used by native crows in New Zealand. They drop their favorite nut on a busy road, then wait for a car to run over the nut and crack it open. To avoid the danger of speeding automobiles, some crows drop the nut in a pedestrian crosswalk, and then wait for the light to change.

But what about those hard shelled mussels favored by diving ducks? When I did some research, I learned that opening a mussel requires a special blade and considerable adeptness. Or, the mussels can be steamed; the bivalve opens and the tasty meat is then readily accessible. I remember one time on the Maine coast when we enjoyed a dinner that consisted of a huge plate of steamed mussels. However, the combination of place, occasion, companion, and the aphrodisiacal quality of mussels banished any curiosity I might have had about how diving ducks might get at the tasty meat, or whether it contributed to a duck randiness.

Omnivorous gulls occasionally exhibit an epicurean taste for mussels and other shellfish. They carry the tightly closed shellfish aloft, then drop it on rocks - or a roadway. They repeat this exercise until the shell finally opens, or breaks. Then they dine.

But how does the hen eider which I saw with a shellfish in her bill get at the meat. First of all, she swallows it whole. After a recent meal, I felt like the food I had consumed was resting in my stomach like a solid lump, a heavy brick weighing me down. But a mussel or mollusk, shell and all? That must really feel like a brick.

And yet, mussels are the favored food of diving ducks, and some dabbling ducks. The shellfish is swallowed whole and then the double stomach takes over. Complex contractions move the food back and forth between the glandular stomach (proventriculus) with its acids and enzymes which dissolve and digest, and the muscular stomach (gizzard) with its grit and stones which grind, pulverize, and mix. A study done on black ducks demonstrated that they can completely digest and pass a blue mussel in 30 - 40 minutes.

The hen eider which I watched with the large shellfish in her beak was unusual. Generally, they prefer smaller mussels which have less nutrition but which pose fewer problems when being swallowed.

Finally, I should add a disclaimer. Here and elsewhere I refer to the “tasty” meat, or morsel, inside the hard casing of a seed, nut, or shellfish. We may dine on mussels for their epicurean delight, perhaps their stimulus to the libido, and maybe their nourishment of the body. The hen eider which I watched was only concerned about the latter. Her complex and efficient digestive system quickly dissolves and grinds the hard shell and digests the meat. What taste buds she may have play no role in her menu selection. The diet of the eider has been determined by the remarkable and complex stomach which can digest a stone - or at least, food which looks like a stone on the outside.

Good birding!

Diving Ducks Identified

Last Sunday I posted photos of diving ducks. Here is the ID. In each case I had the advantage of having watched, and photographed, the bird swimming on the surface and then diving. If I found these photos without the context, I would have been hesitant about putting a name on them.

Diver #1 - Red-breasted Merganser

Diver #2 - White-winged Scoter - I am not sure it was fair including this one since the white-wing was not at all visible, but then it is not visible in the companion photograph below which is a good thing to know when looking at black ducks. It took me a lot of searching to discover finally that the Surf Scoter also has red legs, but not the Black Scoter. If anyone knows how to distinguish White-winged & Surf in the diving photo, I would love to hear from you. I had the distinct advantage of watching the lone White-winged Scoter, so IDing the photo was not a problem

Diver #3 - Common Eider

Diver #4 - White-winged Scoter

Good birding!

Raptors Highlight Coastal Birding

On a coastal birding trip during the winter, I expect to see a few unusual gulls. I expect to see many sea ducks, like the three scoters and Common Eiders, and maybe (very maybe) if I am very lucky, a King Eider. I expect to see diving ducks, like the Common Goldeneye and Bufflehead, and especially the wonderfully patterned Harlequin Duck whose plumage is rivaled only by the Wood Duck. I expect to see Red-breasted Mergansers with their wild crests blowing in the wind. I was not disappointed in these expectations.

On a winter coastal birding trip, I also expect to see Horned Grebe. On a really good day the single wintering Eared Grebe in the Gloucester harbor might seen, and in the ocean off of Cape Ann I might see a Red-necked Grebe. The Eared Grebe was missed but I did see the Horned and Red-necked Grebes.

On a winter birding trip around Cape Ann, I expect to see the Black Guillemot. An alcid that is black with big white wing patches in summer, in the winter is it a gray and white bird which disappears against the gray and white winter ocean. When it is seen, it dives, because that is what it does, but it often feels as though the bird is deliberately teasing. I also hope to see other Atlantic alcids, those ocean birds that come ashore only to breed - like the Common or Thick-billed Murre, the Razorbill, and the Dovekie. I saw the Dovekie in early January, only the second time in my bird watching chronicles that I have recorded it. All of these alcids have been reported, and were probably present at various places off shore, but I did not find them on this trip.

Birding around Cape Ann in the winter, I know where to look for the Great Cormorant, cousin of the very common Double-crested Cormorant which often occurs up in our area. The Great Cormorant winters along the New England and mid-Atlantic coast, then returns north to the Canadian maritime provinces to breed.

I expect to see Common Loons at many places along the coast and in the harbors; its plain gray and white winter plumage is a striking contrast to the handsome breeding plumage of the loons we may see on some of our lakes and ponds in the summer. From time to time, I even see a Red-throated Loon, though in the winter its red throat is just a memory.

On a winter coastal birding trip, these are the birds which I expect to see. What I do not expect, is to have a winter coastal birding trip that is an outstanding day of hawk watching - or more precisely - raptor watching.

It started late Friday afternoon with a quick trip to Salisbury Beach. Even in winter, I expect to see Northern Harriers hunting over the frozen marsh. This one was a male. The male harrier is one of the most beautiful hawks in flight - gray above, white below, with contrasting black primaries and a trailing black edge on its long wings. The harrier’s hunting style is a dipsy-doodle, rocking and rising on long wings, then dipping low across the marsh grasses, tipping left and right.

But the harrier was unable to mind his own dipsy-doodle flight. A dark bird with pointed wings swooped at him, sped upward, circled rapidly, dove at the harrier again in a deliberate near miss. Merlin.

On Putney mountain, a streaking hawk that brings a breathless what-was-that? - is a Merlin. Coastal hawk watchers know the Merlin as a bird with attitude, the falcon that will harass anything flying, often for what appears to be sheer fun. But this Merlin seemed to have a dual purpose. She was defending her hunting territory, while also hunting opportunistically. The harrier dipped toward the top of pine trees, flushing song birds into the air. With precise timing, the Merlin dove at the harrier, turning the much larger bird away from the trees, then instantly veering to make a grab at a flushed songbird. The Merlin came out of her dive with empty talons - this time. The flight display we watched made it clear that the Merlin would dine soon.

The next morning on the Jodfrey Fish Pier in Gloucester harbor, I turned my scope to the Gloucester town hall. A Peregrine Falcon was wintering in the bell tower. Before I could find the falcon’s perch, someone in the group was pointing overhead. The Peregrine was on the wing. Effortlessly it circled over the piers, the warehouses, the harbor, patrolling hundreds of yards in seconds. Sea ducks were nervous; even gulls were uneasy, milling aimlessly. At first, the Peregrine’s flight did not seem all that impressive as it flew above us, until we timed the passage from the pier to the warehouse a quarter mile away where pigeons scattered to safety at the last fraction of a second. The Peregrine’s flight demonstration, by itself, defined good birding for the day.

Mid-afternoon, we drove north from Cape Ann for a return visit to Salisbury Beach. A large bird with v-shaped wings flew above the state highway. As it came low over the roadway, the back-lighted wing pattern was not that of a Turkey Vulture. Rough-legged Hawk. A wide berm allowed us to pull over, and spill out without the risk that our binoculars would get run over by a passing car. Two dark morph Rough-legged Hawks hunted over the open fields, and chased off a pair of Red-tailed Hawks. Hawks of the tundra, Rough-legged Hawks often winter in coastal marshes and open farm lands. This pair seemed unwilling to share the fields with the resident Red-tails.

At Salisbury Beach, our target was the wintering Snowy Owl. We were looking for a bulky white bird, probably perched somewhere in the snow covered marsh or nearby dunes. Simple to sight, right?

Inside the state reservation, cars lined the road. On the cold, windswept marsh, there could be only one reason for those parked vehicles. A couple of hundred yards from the roadway, tens of thousands of dollars worth of camera equipment was lined up, pointed at the top of a dune. We joined the line-up that was ogling the handsome male Snowy Owl.

As for the Snowy Owl - well, this powerful Arctic predator regarded the lined up bird watchers and photographers with imperious detachment. He knew that he was lord of his realm and assumed that these strange creatures would keep their distance. And they did.

Eventually we moved on to the frozen and unoccupied campground - unoccupied except for the day-visiting winter birders. We did not find the White-winged Crossbills which we had seen the previous afternoon, but the Merlin was there. This time, she was perched atop a leafless tree, surveying her realm. Her feathers ruffled slightly in the wind, but otherwise she was the unruffled guardian of her realm.

The winter coastal birding yielded what was expected and was a day of good birding. But the unexpected show from the hawks and the owl made it a day of great birding!