Cape May warbler
Cape May warbler
In a way, the upcoming flurry of May songbirds resets the birding calendar for Maine bird watchers, as throngs of seasonal sparrows, flycatchers, tanagers, and thrushes enliven the greening woodlands. In past decades, we often referred to American robins as traditional harbingers of spring, but a sizeable portion of robins now over-winters along the coast.

Several variables, such as changeable weather systems and weekly spring temperatures, affect the pace of migration at the species level. Another significant factor is the travel distance between southern wintering grounds and northern nesting locations. Current gatherings of spring robins seen on lawns and fields have wintered somewhere within the Eastern U.S., probably near New England. A prolific nester that produces several broods a year, robins quickly settle into early territories and commence nest building. Recently, I watched as robins carried bulging clumps of browned lawn grass inside an evergreen shrub below my bedroom window. On alternate trips, they carried bits of mud to form and cement the base of the nest.

One particularly colorful family of birds — the tiny wood warblers — signifies springtime for many of us. As a group, warblers are quite diverse in terms of their nesting habitats and unique habits. The specifics of nesting run the gamut from nests built on the ground to all the way to treetop levels.

Arrivals of spring warblers span several weeks, but pine warblers are one of the earliest. As their name suggests, this species is closely linked to large white pines. They differ from neo-tropical warblers, since pine warblers winter in the Southeastern U.S. The pine warbler is one warbler that eats large quantities of seeds, primarily those of pines. This propensity also leads them to occasionally visit bird feeders. In fact, I observed one at my home feeding stations on April 16. Some individual stragglers push northward as early as February and may even nest as early as late April.

One of my favorite early warblers (and all-time-favorites) is the black-and-white. Decked out in two primary colors, they rate a fine pen-and-ink drawing. Their genus name, Mniotilta, means “moss plucking,” a reference to their probing techniques on mosses and barked trunks and branches. Equipped with an extra-long hind toe and heavier set of legs, B&Ws are agile on bark surfaces. Less reliant on catching flying insects, they can reside earlier than other, more insect-dependent species.

Most Cape May warblers, on the other hand, won’t pass through coastal Maine until mid-May, while en route to northern boreal forests. A long-distance migrant, they winter from Central- to South America. This distinctively marked bird received its name from the place where it was first collected as a type specimen — Cape May County, New Jersey. Their historical numbers have vacillated in conjunction with cyclic spruce bud worm infestations. Populations for this species — a fir-spruce forest specialist — appear on the rise in recent years.

Cape Mays can be hard to discern as they flit and forage amidst thick spruce branches. Highly charged by reproductive hormones, some males will sing before reaching the breeding grounds. The Cape May’s typical song is described as “3-8 thin, very high-pitched ‘tseet’ notes, all on the same pitch.” Not real helpful, you say? I would agree. The best method I’ve found to learn bird song is to spot a given bird that is singing or vocalizing and try to pair its visual image and auditory aspects. This requires commitments of time, patience and practice.