Donald Skelly, age 13, of Spotswood, New Jersey, for his question:

Is the crossbill found in Canada?

Tracking the whereabouts of the crossbill can become a bird watcher's headache. Most birds are fairly faithful to the habitats and migratory paths of their ancestors. But this charming little member of the finch family likes to change his address without notice. However, at some time or other, he is likely to make an appearance in almost any part of the United States or Canada.

North America has two native crossbills and both of them favor evergreen forests. They are perky six inch finches with a remarkable feature. This is a sharp bill that looks like two hooked fingers crossed for good luck. The sturdy bill is needed to pry seeds from pine cones. Crossbills may be found almost everywhere that this food is plentiful, though they rarely stay in the same place for very long.

Sometimes a few couples decide to spend the whole winter in the western forests of the United States and Canada. For reasons known only to themselves, they may fly farther north or farther south for the summer nesting season. In a general way, their unpredictable roamings throughout most of North America may be guided by food supplies.

The males of both species wear colorful plumage and the females wear less noticeable outfits of greyish green, tipped with patches of yellow and white. The male American red crossbill is a warm shade of brick red with darker wings and a brighter tail. The male.white winged crossbill wears a bright shade of pink, accented with a black tail and flashy wide white bars on his dark wings. This species is even more prone to flit from place to place, though both are quite unpredictable travelers.

The nesting season begins in the spring, when a couple of crossbills chance to come upon a grove of evergreen trees where the boughs are loaded with suitable cones. The nest is built on a fairly high bough among the dense conifer foliage. It is a neat structure woven from grasses, twigs and rootlets and softly lined with scraps of hair.

Mrs. Crossbill lays four or five pastel green eggs, freckled all over with spots of pale lavender and brown. The major food item on the family diet is pine seeds, pried from their tough cones with the greatest of ease. As soon as the youngsters are ready to travel, the family moves on to some other unscheduled spot in Canada or the United States.

The crossbills belong in the order Passeriformes, or sparrow like birds. They share the family Fringillidae with the finches and song sparrows, the buntings and grossbeaks. Their cousins tend to keep up their ancestral habitats. But the crossbills are continental gypsies. A couple of parents rarely if ever return to the location where they built such a durable nest last year.