Showing posts with label Common Eider. Show all posts
Showing posts with label Common Eider. Show all posts

Monday, December 14, 2015

A few more from Cape Ann last week

Andrews and Hallibut point were good spots for large rafts of eiders and  Harlequin Ducks. Also saw a couple of Northern Gannets, and Red-throated Loons. Missed finding Purple Sandpipers, but a few Sanderlings were sleeping on the rocks.

Harlequin Ducks

Harlequin Dcuks and Common Eider (hen)

Rose thrips

Sanderlings

Sanderlings
And finally ... scene from Sandy Point on Plum Island. I had hoped for raptors and owls in the late afternoon. Had some reports, but except for a Red-tailed and harrier, they were not flying when I went by.

But I also love the bleak beauty of coastal dunes ...


Good Birding!

Saturday, December 12, 2015

Cape Ann this week

Some additional images from this week's day trip to Cape Ann, Massachusetts.

Common Eider (drake)


Hedrring Gull

Common Eider (1st winter drake)

Rocky Neck

Common Loon (Adult non-breeding)
And finally ... probably my favorite photo of the day ...ds

Herring Gull
Good birding!

Saturday, January 30, 2010

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!

Friday, January 29, 2010

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!

Thursday, January 07, 2010

Coastal Birding

A day trip yesterday to the Massachusetts coast - Cape Ann & Newburyport area - produced good birding (which is something of a redundancy, since birding is, by definition, good - and a good way to spend a day).

About halfway through the morning, I realized that Common Loon was still absent, and made a particular point to look for it. No luck. Perhaps they were out to sea, or went - were blown - south by the recent, and rather strange, coastal storm.

Other than that, the usual suspects were present, though it seemed to be that the numbers were low. Tide was low in the morning, and the birds that were seen were rather far out, so photography was difficult.

On a day when wintering sea ducks, grebes, and alcids were the expected targets, the highlights were quite different.

At Eastern Point Lighthouse, an American Pipit posed briefly ...

... and at Salisbury Beach, a flock of 50+ Snow Buntings swirled around the campground.

Buffleheads were quite common all along the coast. The sharp contrast between the Bufflehead's bright white hood and bright white body with the dark wings, head, and neck have made this a challenging bird to get a good photograph of, and I have yet to meet the challenge. Nevertheless, in the low angle of the winter sun, the head and neck glistened with an iridescence that was stunning. This gentleman quite apparently has his eye on the lady.

The contrasting light and dark plumage on the Harlequin Duck poses the same photography challenge as does the Bufflehead. They were quite common along our route from the Granite Pier to Andrews Point - a reliable area to see these birds if you need them for a life list.

The King Eider was out to sea, or at least our of our sighting, yesterday. Common Eiders were - well, common - though there were no huge rafts as I have often see, and most were too distant for good photos. But this female was near the breakwater at the lighthouse ...

Good birding!

Monday, January 05, 2009

Birding Cape Ann

I finally got over to Gloucester, Massachusetts, for a day of winter coastal birding. The highlights of the day were a King Eider (too distant for a good picture, but very recognizable), Thick-billed Murre (way too distant to even try for a picture), and Dovekie (barely popped to the surface before diving again).

Among the unusual wintering gulls, was the Black-headed Gull (in rear near rock). Even though the gull is small in this photo, I liked the other gulls and ducks in the foreground. (Greater Black-backed, Herring, Common Eider, female Red-breasted Merganser). This was near the fishing pier in Gloucester Harbor.


Also in the harbor was a first year Iceland Gull, or as the more precise and obsessive birders like to say, a "Kumlien's" Gull (a subspecies of a difficult to classify light-colored, or light gulls).


On Niles Pond, there were at least four additional Iceland (Kumlien) Gulls among the many Greater Black-backed and Herring Gulls of assorted ages. Also at least two Glaucous Gulls and a Nelson's (Glaucous x Herring. Hockey players kept the roosting gulls at a considerable distance. Glaucous is the large white gull in the center.


Sea ducks are always a significant feature of winter coastal birding, and all of the usual suspects were there, including all three scoters. This White-winged Scoter was quite close ...


... and one of the showiest of all ducks, the Harlequin Duck.


A day of Good Birding.

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