MaineToday.com, ME – Jul 2, 2014
By Herb Wilson,
Maine provides breeding ground for six species of swallows. Tree swallows, the first to arrive in the spring, are the most abundant. Barn swallows are nearly as common. As colonial nesters, cliff swallows and bank swallows may be locally abundant. Rough-winged swallows are even less common in the state. But the least abundant is the purple martin.
Purple martins are the largest swallows in North America and among the largest in the world. They are an extremely popular bird, recognized by many non-birders. Males are completely covered with a glossy blue-black plumage and are the only swallows in North America with a dark belly.
Females with brown upperparts and lighter underparts are similar to other female swallows but can be distinguished by their large size and the prominent brown or gray collar around the nape. A martin’s chattering vocalization adds to its charm.
Although purple martins are scattered in parts of western North America (parts of the desert Southwest and coastal areas from British Columbia to central California), they are continuously found throughout most of the Eastern states. However, they occur discontinuously in New England. In Maine, they occur in a broad swath proceeding northeastward from coastal York County to the Calais region of Washington County. This band continues northeasterly into New Brunswick, ending at the northwestern tip of Nova Scotia.
MAINE COLONIES SMALLER
The Maine Department of Inland Fisheries and Wildlife estimates no more than a couple of hundred pairs are in the state. Purple martins are colonial nesters, but Maine colonies are typically smaller than those in Southeastern states.
Although purple martins nested in natural cavities before the development of the United States by European immigrants, nearly all Eastern birds now nest in human-made apartments. Elaborate martin houses may be used as well as gourds, hollowed out, and hung close together. The provision of houses may have caused martins to become colonial. Martins in the West often nest solitarily in natural cavities.
Because of their popularity, incorrect information about purple martins gets published and reprinted. Some of these myths pertain to the diet of purple martins. Manufacturers of martin houses often encourage the purchase of their products by touting the effectiveness of martins in controlling mosquitoes. Don’t believe it!
Martins tend to feed several hundred feet above the ground and always take flying insects. Their prey are mostly large species like dragonflies, wasps, bees and Japanese beetles. Martins feed only during the day. Mosquitoes, on the other hand, tend to be found in damp grass close to the ground during the day and may be active only at night.
No study of martin diets has ever shown mosquitoes to be a significant component of their diet.
WEATHER A FACTOR IN FEEDING
Depending on flying insects for sustenance, purple martins are subject to the vagaries of the weather, particularly in New England and the Maritime Provinces. Cold or extended rainy weather during the early part of the summer can reduce the number of flying insects and spell disaster for purple martins.
The nesting process is slower than in many other songbirds. Incubation takes place for 15 to 20 days before hatching. The female does most of the incubation, although the male may take a turn while the female leaves the nest to feed. The young fledge 28 or 29 days after hatching.
Females begin laying eggs the first 10 days of June in Maine and Nova Scotia.
It’s wonderful to have a martin colony on your property. The nest box needs to be higher than trees in the area, and no tree should be within 60 feet of the martin house.
The martin house can be placed between 30 and 120 feet from human habitation. Martins have learned that proximity to a human house lowers the risk of predation.
Lots of useful information can be found at two Web sites: http://www.purplemartin.org and http://www.purplemartins.com/
