A coworker of mine at Fogler Library came to the desk the other day and commented on the robins that had appeared the day before.

“They must be confused,” he said, voicing the surprise of many who see robins around here during the winter.

A reader also wrote in to express a similar sentiment.

“I was quite amazed to look out my back window the other day and see 20 or 30 robins feeding in an old apple tree … first time in my 73 years of living up here that I’ve ever seen a robin in the dead of winter. Checking further I found it is common for them to winter here – oh well, just goes to show ya – you’re never to old to learn.”

Contrary to popular belief, the sight of robins is not necessarily a sign of spring, nor do they appear only with its advent. The American robin inhabits all of the United States and most of Canada; many birds do not migrate far from their breeding grounds, and those that do – residents of Canada, for example – may still remain in the northern tier of the states. This gives them a breeding advantage.

“Robins winter in the Greater Bangor area every year,” said Judy Markowsky of the Fields Pond Nature Center. “They are males, and this strategy positions them well to stake out a prime territory in Canada in the spring – if they survive the Maine winter!”

Which brings us to the next question: How does a bird that lives on insects and earthworms in the warm months survive our winters, when these creatures are unavailable to them? The answer, in part, is eating habit: They switch to a diet of berries and other fruit.

Most fruit-bearing trees and shrubs retain their provender throughout most of the winter; some longer than others. Many fruits – such as blueberries – are relished as soon as they ripen in late summer, while others (crab apples, winterberry, and highbush cranberry) ripen later and last throughout the winter. If you have the latter anywhere on your property, sooner or later you will see robins, waxwings, or grosbeaks coming in droves to clean the tree of its fruit.

You can also provide an assist by adding raisins, apples, currants, grapes, even bananas to your bird feed menu. Offer these on a bare patch of ground or a platform feeder, or run a thin wire through them and hang them from a branch (keeping squirrels in mind!). Robins and other winter-fruit eating birds will be sure to take advantage of it.

Chris Corio, a volunteer at Fields Pond Nature Center in Holden, can be reached at fieldspond@juno.com