A Few Local Birds

The most common winter bird around Cape Cod is the appropriately named Common Eider. They are a large salt water duck of rather shallow waters where they dive for their food. The dense flocks vary in location depending on the changes in sand and shellfish. After storms the bottom of the ocean is different than it was before the storm. The “prey” items populate new areas and the eider find them.
There are several forms (morphs) of Common Eider and several species within the group of ducks called eider. We get a few King Eider each winter but they are scattered and random. Common Eider are always around and in large numbers each winter. They are nesting birds of the rocky shores of the Canadian Maritimes and have recently begun to nest on the Boston Harbors Islands where there are now about 500 nests each summer.
The eider down of warmth and insulation fame is taken from the breast feathers of the female – or rather collected from their nests. Nowadays the trick is to keep a nesting colony together (a bit like a nesting duck farm) and to take the soft and fluffy down feathers from the nest just before the eggs are laid. The missing down feathers are replaced by fine grasses which seems to satisfy the females. In centuries past the fresh down would be taken early and another harvest of dirty feathers after nesting was over and the nest abandoned. Like all ducks the young are precocious and leave the nest for the water as soon as they are out of the egg and dried off.
Our landfills of the 1960’s, 70’s, and 80′ were, for the most part, “capped” in the 90’s and 2000’s. They had all the donated and stockpiled trash mounded and covered and then the “mountain” was capped with rubber sheeting, covered again with soil, and finally planted with grasses; creating big grassy hillocks.
These hills cannot grow trees as the rubber cap should not be penetrated. Thus many old dump sites have become grassland habitat and recently many have become home to solar panel arrays. One of the birds that seems to benefit from the capped trash piles is the Red-tailed Hawk (RTHA). They choose to feed on small mammals and the grasses produce meadow voles (Microtus pennslyvanicus, also called Meadow Mouse) in pretty good numbers. These small rodents weighs just under 2 ounces but are prolific and abundant. A few squirrels and a rabbit now and then rounds out a pretty substantial Red-tail Hawk diet.
Because there are tons upon tons of composting trash the landfill produces methane and this needs to be vented; in many cases it is vented by burning. In the case above the vent is simply a wind driven fan that helps draw methane from under the surface of the landfill, and it provides a nice observation post for the local Red-tailed Hawk.
The state bird of Massachusetts (and Maine) is the small, perky Black-capped Chickadee (BCCH). This is a common bird year-round. It is easily drawn to feeders by black oil sunflower seed or hulled sunflower meats and they seem to be a happy visitor even in cold weather. Banded flocks of BCCHs are seen to rotate through a neighborhood with “group A” there for a while and “group B” replacing them and so on. In some areas there are four and five groups (most likely with a family basis) that will visit a feeder during the day. The rest of the day, even in brutally cold weather, they will travel the nearby forests, thickets, and street trees looking for more natural foods.
A bird this size has a very small body weight (mass) and a comparatively large expanse of skin (surface area); this makes it difficult to stay warm as the skin gives off heat and thus cools the body. But these little guys (and kinglets, and creepers, and goldfinches) are able to stay well insulated and well fed. The insulating feathers keep heat from blowing away and lots of food keeps the burning of calories at a high level. It seems that maintaining heat must be a daily challenge in these northern winters; you can imagine the impact of a snow storm or even worse, an ice storm.
Four winters ago we had over 100″ of snow and lost a high percentage of the resident Carolina Wrens (CAWR). The other small birds were less impacted that long winter. Perhaps they were able to move south away from the snow, where the CAWRs were unable to, or just didn’t, move away. It has been three breeding years and the Carolina wrens are back in pre-snowy-winter numbers.
One of the more interesting features of a winter out on Cape Cod is the great numbers of American Robins (AMRO) that winter here. These thrushes are not the same ones that nest here, at least for the most part. Our wintering robins probably nest in the Canadian forests along and inland from the Maritime provinces. In appearance they are darker and more richly colored. Our nesting birds are often a soft brown and charcoal where the northern birds are a rich brown and black.
Our robins feed on cedar and holly berries into the winter. They roost in flocks in tall wetland grasses or Red Maple swamps. One of the ways to attract the American Robin is top plant fruiting shrubs; especially shrubs that produce small crabapples. These sorts of shrubs tend not to spread into native plant areas and are relished by the wintering robins, and Cedar Waxwings as well.
Several things about wintering birds has always interested me; two of these things are 1) how they can eat such cold food without effecting their body temperature and 2) the chill factor on the eyes of a bird flying 20-40 miles an hour in cold cold air must be
really really cold – well below zero in many cases. How can eider duck eat 35 degree shell fish scavenged from the ocean floor (crushing the shells in their muscular gizzard) or a gull or raptor fly into the wind without freezing the surface if their eyes?
The soft looking and seeming delicate Cedar Waxwing (CEWA) eats fruits and flowers. In the spring there are few natural sights that are as lovely as a flock of CEWAs eating apple tree flower petals.
This is not an uncommon bird but they are sketchy. Sometimes found in pretty regular numbers and other time really hard to locate. They are named for the “waxy” bubble that forms at the end of the feather shaft that appears to be a small drop of red wax.
For years, and still to some extent, the real function of these waxy droplets was unknown. It still is unknown for sure but more and more evidence points to one of nature’s great evolutionary driver’s – the ladies like it so the male do it!!
The older stronger and healthier males are thought to have more red than younger and less fit birds. So it seems the ladies choose mates by the amount and number of red feather-tips that a male has.

One thought on “A Few Local Birds

  1. I am heading to my house near Bayview Beach in a few days, so this looks like a perfect primer for what I might see in the wetlands and woodlands nearby. Thank you

    Like

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