Laura Erickson's For the Birds

Thursday, March 15, 2012

Robins

American Robin
(Transcript of today's For the Birds)

Back in early February, I saw an American Robin in my backyard. Part of the time he was eating berries, and part of the time he was rummaging through leaves in the back of the yard for earthworms. This may have looked like a little preview of spring, but it didn’t sound like it—he wasn’t singing yet. Some robins spend the entire winter in Duluth, not due to climate change directly, but because they wander widely, wherever they can find berries and crabapples. The ones wintering here aren’t necessarily the same ones that will breed here, but robins that winter in the northern tier of states and in Canada do have the advantage of a shorter distance to travel to their breeding grounds, assuming they survive the winter. Males that winter further south have the energy expense and dangers of long-distance travel, but they don’t deal with severe cold. Weather patterns change from year to year, and robins that have the advantage one year may not the next. In the long run, climate change may have increasing advantages for robins wintering in the north, because the South is having more tornado-level storms in winter, while the North is having milder winters. But as long as there are huge amounts of fruit in the South, we’ll almost certainly continue to have robins wintering throughout their range for the foreseeable future.

American Robin

Wherever they are outside the breeding season, robins are constantly on the move, but the bulk of robin migration northward in late February and March follows the 37-degree isotherm. With the current warm front, we can expect robins to start appearing throughout the north woods in the coming days. I always get a surge of joy when I hear my first one. Considering how variable the weather can be in early spring, it’s cool that once our first spring robin appears, he sings day after day, whatever the weather brings, including heavy snow and ice storms.

Female robins return a couple of weeks after the first males. By then, territorial disputes are mostly settled, and females can get down to the business of nesting. Few robins in towns nest in trees anymore—their eggs and nestlings are just too vulnerable to the burgeoning numbers of urban crows. Those robins who still do nest in trees invariably choose a thick evergreen for their first nest, since they lay their first eggs before leaves have emerged enough to provide protection from sun and rain in deciduous trees. More and more robins nest on houses and other structures close enough to people to get some safety from the crows. Most people enjoy their backyard robins, but when they nest on a porch light or something else right by an entry, the robins may make a mess, start dive-bombing us, or make us worry about disturbing them. Setting out robin nest platforms in more desirable places on the house can help both us and them. Carrol Henderson’s book, Woodworking for Wildlife, available in bookstores and from the Minnesota DNR, has excellent plans and advice for placing robin nest platforms.

American Robin

Few researchers focus on robins in banding studies. Those adults who are successful breeding in an area may return for several years straight—the oldest wild robin known lived to be almost 14 years old—but their young seldom return anywhere near where they were raised, and individual robins seldom return year after year to particular wintering areas, so their movements are still not at all understood. I love how a homey backyard bird that just about everyone notices and recognizes can keep so many secrets from us.

American Robin

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