The clear whistle reached me across the distance. The sky was a soft blue and the warming breeze stirred through the boughs of tall white pines, sounding like the ocean. These sensations combined to remind me that winter was on its way out.

Spring is coming, the song seemed to say; spring is coming.

I couldn’t see the bird that was producing the full, sweet whistles, but I knew what it was: a tufted titmouse.

This little songbird with the strange name has slowly been expanding its range northward. It is quick to take advantage of backyard bird feeding stations, showing a preference for sunflower seeds. It also relies on the nuts of beech and pin oak trees and various wild seeds in winter. What it doesn’t eat on the spot it caches somewhere within its territory, which encompasses widely varying habitats. It prefers deciduous and mixed deciduous-coniferous forests, as well as swamps, parks, and suburban neighborhoods with many trees, which it relies upon as a source of nesting cavities. However, it will also use nest boxes provided by humans.

The tufted titmouse is an elegant-looking bird with a gray back, tail, and head, a light tan underbody, a black forehead, and a swept-back crest on its head, similar to the northern cardinal’s. Its whistled song is a two-noted phrase described as, “peter-peter,” most often sung by the male but also by the female.

The titmouse engages in cooperative breeding. Young from the previous year will stay with their parents to help them raise the new brood, instead of going out, finding a mate, and raising a brood of its own. Certain other species of birds engage in this behavior, but the titmouse is the only one to do so in its family, which includes the chickadees.

A factor that influences this type of behavior in other birds – such as Florida scrub jays – is the small territory and limited range and specialized habitats these birds require. Young Florida scrub jays stick around to help their parents simply because there is a shortage of real estate for them to occupy. They therefore wait until a spot opens up within a territory, as will happen with the death of a bird; they then can claim it and seek a mate to raise their own young.

This type of behavior ensures the greatest amount of success for that particular bird’s DNA line. Even though a young bird may not produce its own young, in helping its parents it ensures its siblings a greater chance of survival and eventual reproduction. However, this has not yet been proven to be the case with the tufted titmouse. Researchers so far do not have information on the success of a breeding pair when helped by its previous offspring.

I wondered if the tufted titmouse resorts to helping as a result of a scarcity of nesting sites, since others of our native cavity-nesting birds (such as the Eastern bluebird) have suffered population declines due, in part, to a lack of nesting cavities and also to competition with nonnative, human-introduced cavity nesters such as the European house sparrow and the European starling. Thinking of the number of other cavity-nesting birds – woodpeckers, chickadees, nuthatches, tree swallows – I guessed this could be a factor. More research is needed before this can be determined by ornithologists, of course.

In the meantime, I’m enjoying the sweet whistled song of this engaging little bird, hoping it will stick around for years to come.

BDN bird columnist Chris Corio can be reached at bdnsports@bangordailynews.net