Female Killdeer on nest (Photos by Don Reimer)
Female Killdeer on nest (Photos by Don Reimer)
By the second week of June, spring migration has largely achieved its yearly goal of placing birds at their intended nesting destinations. There are always some tail-end stragglers, of course, and intriguing species of out-of-range birds that somehow find their way into Maine. Recent examples include three White Pelicans seen in southern Maine. An immature Brown Booby, a large tropical seabird, was spotted off Monhegan and later observed near Mount Desert Island by lucky participants in the Down East Spring Birding Festival. And a vagrant shorebird normally found in western U.S. regions, a slender Wilson’s Phalarope, recently surprised birders at Weskeag Marsh.

Meanwhile our local nesters are getting down to the business of rearing young. Data results from the Maine Bird Atlas project are accumulating as the tempo of nesting efforts quickens and becomes more obvious to Atlas observers. I’ll share three instances where I applied the Atlas breeding criteria to gain confirmed breeding status.

American Robins start nest building by mid-May and typically produce two to three broods annually. My photo of this particular robin nest has some historical perspective. I was familiar with this site since robins reconstituted the same nest from last year. Constructed of fine grasses, weed stalks and an interior mud lining, the nest sat on a wooden beam of a busy home porch where three eggs successfully hatched. Confirmed breeding status was established by applying the Atlas code “NY” = nest with young. I discovered an interesting nesting phenomenon at a neighboring home that is worth mentioning here. Some female robins build multiple partial nests in a side-by-side layout. Possibly due to “lack of nest orientation,” or perhaps an inexperienced first-time nester, triple nests were separately constructed along a deck girder at the house next door! Just one nest was utilized, however.

Arriving in mid-March, pairs of Red-Winged Blackbirds are currently building nests as some earlier members are already feeding young. The female Red-Wing in my photo took repeated trips to her nest site, transferring long strands of dry grass into emergent cattails. Her animated male partner sailed back and forth above the nest site, making scolding “check” calls and flexing his crimson epaulettes for added effect. Some males are polygamous, mating with two to three females, depending on the quality and attractiveness of their nest territory. In the Red-Wing’s case, the confirming breeding code was “NB” = nest building.

While the majority of shorebirds nest in high-tundra regions, Killdeer are common Maine nesters. One might ponder why they nest on totally open ground that could become vulnerable to predators, but the strategy works well for them. Nests are often in close proximity to human habitations such as lawns, airports, cemeteries and even parking lots.

Selection of nesting sites may depend on availability of suitable ground cover such as graveled surfaces, stones or small rubble to help camouflage the nest — a simple depression in the soil lined with stones, wood chips and assorted debris. Nests with eggs have been found in heaps of broken glass. The male Killdeer creates various scrapes on the ground and the female chooses one.

Hatched with eyes fully open and a thick coat of downy feathering, the precocial Killdeer chicks come out running. And since incubation of the four-egg clutch doesn’t commence until the final egg is laid, the chicks all hatch within hours or minutes of each other. This critical detail contributes to the odds of survival for these highly mobile but temporarily flightless hatchlings. Atlas breeding code for this one? “ON” = occupied nest.