Thursday, February 27, 2014

A Sure Sign of Spring

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Red Winged Blackbird (male).
 Which bird do you associate with the arrival of spring? The robin, right? It turns out that the appearance of a robin here on the South Shore is not an indication that spring is on its way. However spying a red-winged blackbird at your feeder: now that’s a different story.

Usually in early March, male red-winged blackbirds return to their breeding grounds, to prepare for the arrival of the females. Their aim is stake out, and guard, the best territory, so as to attract the most appealing mate.

My father likes to tell a story about a city-dwelling friend, who after hearing my dad’s excitement about the arrival of red-winged blackbirds on our deck, inquired “What do they look like?”

“Well,” said my dad, stating the obvious, “They are black birds, and they have a patch red on their wings.”

So yes, the name of the red-winged blackbird is indeed an apt descriptor. It is a medium-sized bird, just under two ounces in weight, and about 8.75 inches in length, with a 13-inch wingspan. Males are glossy black in color, with red and yellow badges, or “epaulettes,” on their shoulders, which they can display or conceal as needed. Females are less bold in color, usually a streaked dark brown, often with white above the eyes.

In spring, they are hard to miss – especially the males, who create quite a racket in their quest to be noticed by potential mates. Males will perch in high places and sing “Oak-a-ree!” or “Conk-la-ree!” all day long. Females are more apt to gather food and tend to the nest.

I live a stone’s throw from the Green Harbor River. In my back yard, a freshwater marsh divides the upland from a wide, pond-like section of the watercourse. This is prime habitat for red-winged blackbirds, who during the breeding season, favor marshes (both salt and fresh), rivers and streams, damp scrubby roadsides, and even the manmade ponds on golf courses. In winter, they might choose a drier habitat, such as an agricultural field, a wild meadow, or a grassy pasture.

So when they arrive here in spring, after wintering in warmer climes, they set about breeding and nesting. First the males each establish a territory. Next, when the females arrive, the males perch in prominent places, show off their colorful wing patches, and sing. Mate selection is undertaken by the females, but it’s not exclusive. A male may have up to fifteen different female mates at one time, and in a given season, most male red-winged blackbirds have at least two females nesting in their territory. Males actively defend their dominion. They will chase other birds away, fend off nest predators, and if they feel threatened, even harass large mammals including humans.

The females each select a site on which to build a nest. They use mud, grass and decayed vegetation to create a small cup which is seated low among densely-vegetated marsh grass, shrubs or trees. Females typically lay 3-6 eggs, which are pale blue-green or gray in color. After about 12 days of incubation, the fledglings hatch and the mother stays close-by for five weeks to feed them.

The diet of the red-winged blackbird varies. During the breeding season it is rich in protein, and includes insects like beetles, moths, grasshoppers, caterpillars and grubs. At other times of year, seeds and grains are staples.

The range of the red-winged blackbird spans the entire continental United States, most of Canada, and as far south as El Salvador, but the more highly populated areas are the Northeast, Midwest and the western US. Outside of nesting season, they congregate in extremely large flocks (think: millions), often with other types of blackbirds or starlings. They migrate with the seasons, concentrating where food and water are abundant.

As March approaches, the return of the red-winged blackbirds is nigh. Keep an eye out for brightly-colored males, who will bring some light and warmth to these dark, cold, dreary days, not only in a visual sense, but in a spiritual one as well. These shiny black birds with their patches of red and/or yellow on the shoulder are a sure sign of spring!

Sources:
http://www.allaboutbirds.org/guide/red-winged_blackbird/lifehistory

by Kezia Bacon, February 2014

Kezia Bacon's articles appear courtesy of the North and South Rivers Watershed Association, a local non-profit organization devoted to the preservation, restoration, maintenance and conservation of the North and South Rivers and their watershed. For membership information and a copy of their latest newsletter, contact NSRWA at (781) 659-8168 or visit www.nsrwa.org. To browse 15 years of Nature (Human and Otherwise) columns, visit http://keziabaconbernstein.blogspot.com

Monday, February 3, 2014

Go See the Snowy Owls!

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Snowy Owl. Photo by Doug Lowry
 Have you seen the snowy owls on Duxbury Beach? So many people have been talking about them, I’m starting to feel like I’m the only person who hasn’t gone to see them! This winter we have had an unusually high population of snowy owls in our area, so your chances of spotting one are pretty good.

As you may have guessed from their name, snowy owls are primarily white in color, although they do have some brown spots or markings. The males tend to be whiter than the females. They have small golden eyes, and short sharp bills. One of the larger owl species in North America, they measure up to 27 inches in height, and weigh up to four pounds. That’s heavy for an owl – they need lots of layers of feathers to keep warm in the Artic! Their wingspan ranges an impressive 4.5 to 5.5 feet across. In the wild, snowy owls may survive up to nine years – and considerably longer in captivity.

Snowy owls survive primarily on a diet of lemmings, a small Arctic-dwelling mammal. They are nomadic, and generally follow the lemming population. They also eat fish, insects, birds (ranging in size from a songbird to a medium-sized goose!) and other small mammals such as hares and mice. Last year the lemming population was large, and as a result, a greater-than-usual number of young snowy owls were produced.

Snowy owls make their home in the Arctic, in the northern portions of Canada, Alaska, Greenland and Russia. They breed in May, scraping out a hole in the bare ground in which to nest, and often returning to same spot year after year. If food supplies are good, a female may lay 7-11 eggs, while on a not-so-good sustenance year, maybe 3-5. The female protects the nest while the male gathers food. The babies begin to leave the nest after 25-26 days, however they cannot hunt for themselves until they reach about five weeks of age, and their flying skills don’t really mature for another 2-3 weeks beyond that.

In the fall, snowy owls begin their journey south, searching for a place to spend the winter --  a place that is similar to the dunes and grasslands of the Artic tundra. They prefer wide-open, mostly-treeless coastal areas, so our larger, less-developed beaches are prime spots for viewing them. Duxbury Beach is the best spot locally. If you don’t mind traveling farther, Plum Island, Salisbury Beach and Newburyport to the north are also safe bets, as are the beaches of the Cape and Islands. They are also attracted to airports.

You probably won’t see snowy owls at Logan or any of our other local airports, though. Owls pose an airstrike danger, and so they are routinely removed from the premises. Norman Smith, director of the Massachusetts Audubon Society’s Blue Hills Trailside Museum is a hero in this department. For 32 years he has been rescuing and banding snowy owls from Logan Airport, and relocating them to Duxbury Beach and Plum Island. In a normal year, this may involve 6-10 birds, but occasionally there are boom years and the 2013-2014 winter is definitely a boom (the technical term is “irruption”). By the end of December, Smith had relocated 32 snowy owls to Duxbury alone.

Snowy owls typically arrive in Massachusetts toward the end of November, and stick around for a couple of months, before heading north again. The Bay State isn’t their only winter home: they have been spotted as far south as Bermuda, North Carolina and Florida.

While they are here, snowy owls spend their days hunting. They have remarkably keen vision and hearing. Most owls hunt at night, but snowys do most of their work during the day. They look for a spot with a good view: the rolling terrain of a sand dune is ideal, or they may tuck in behind a bush if it’s windy. On calm days, they might choose a less-protected perch, such as a telephone pole or a nesting platform. Generally they are quiet, unless they’re trying to scare away a predator, in which case they may cackle. They sit a lot – often for hours in the same spot, swiveling their heads or leaning forward to get a good look at something. Often, once they’ve captured one, they will swallow a rodent whole! Now that’s something I’d like to see . . .

There’s still time to try to see the snowy owls at Duxbury Beach. While you may want a spotting scope or binoculars for a close-up view, you won’t need any special device simply to catch a glimpse. Please be respectful. MassAudubon suggests that people not disturb the owls by getting too close.

Sources:
http://www.defenders.org/snowy-owl/basic-facts
http://www.allaboutbirds.org/guide/snowy_owl/lifehistory
http://www.patriotledger.com/x919119789/Snowy-ownl-population-spikes-in-Massachusetts#sthash.EL6HKjgY.dpuf

by Kezia Bacon, Correspondent
January 2014

Kezia Bacon's articles appear courtesy of the North and South Rivers Watershed Association, a local non-profit organization devoted to the preservation, restoration, maintenance and conservation of the North and South Rivers and their watershed. For membership information and a copy of their latest newsletter, contact NSRWA at (781) 659-8168 or visit www.nsrwa.org. To browse 15 years of Nature (Human and Otherwise) columns, visit http://keziabaconbernstein.blogspot.com