The nesting season continues apace for many Maine breeding birds.\u00a0 Finding a bird\u2019s nest can be difficult during the incubation period when the incubating parents are still and rarely leave the nest.\u00a0 For songbirds and other birds whose young require feeding (altricial birds), the necessity of frequent visits to the nest to satisfy the seemingly insatiable appetites of the nestlings makes it easier to locate nests after the chicks have hatched.<\/p>\n
Birds of a given species make similar nests.\u00a0 Nests range from small depressions in the forest floor or on a sandy beach to massive structures weighing more than a ton.\u00a0 In today\u2019s column, I will provide an overview of the diversity of bird nests.<\/p>\n
The simplest nests are scrapes on the forest floor, fields or beaches.\u00a0 The nest of a Killdeer is a good local example.\u00a0 The female lays four eggs in a nest scrape just big enough to contain the eggs.\u00a0 As you would expect, the eggs are well camouflaged.\u00a0 In the woods, American Woodcocks and Whip-poor-wills create nest scrapes for their eggs.\u00a0 For most species that create nest scrapes, little effort is made to line the nests with soft material.<\/p>\n
Most birds construct a bowl-shaped nest just large enough to fit an adult\u2019s body.\u00a0 We can consider the bowl-shaped nest of an American Robin as a typical nest.\u00a0 Robins are not great architects but still have a remarkably complex nest.\u00a0 The outer part of the nest is formed of twigs, coarse grass and sometimes pieces of cloth, string or other human-made products.\u00a0 This outer layer gives the nest strength.\u00a0 Within this outer layer, robins place a smooth layer of mud.\u00a0 Finally, a layer of fine grasses is laid down to surround the eggs and aid in insulation. \u00a0Once the outer part of the nest is built, the female sits in the middle of the nest for the rest of the construction.\u00a0 A snug fit is therefore guaranteed for the incubating mother.<\/p>\n
Other species use specific materials for the inner lining of their nests.\u00a0 Palm Warblers, a ground-nesting species in bogs, often place Ruffed Grouse feathers in their nests.\u00a0 Tree Swallows line their nests with feathers, particularly white ones.\u00a0 In the early breeding season, you can see aerial fights where Tree Swallows attempt to take white feathers from another Tree Swallow.<\/p>\n
Ruby-throated Hummingbirds create tiny nests to hold their two eggs.\u00a0 The nest is made of down and small pieces of plant material bound together with spider webs.\u00a0 The outer part of the bowl is covered with bits of lichens to aid camouflage.<\/p>\n
Black-capped Chickadees make their nests in a tree cavity.\u00a0 The outer part of the nest is made of moss and the inner part of spider webs, soft grasses and plant down.<\/p>\n
Waterbirds typically create bowl-shaped nests on the margins of lakes or ponds or even on floating vegetation.\u00a0 In most cases, the outer layer of the nest is made primarily of vegetation.\u00a0 If water levels rise, waterbirds will quickly add additional vegetation to keep the inner part of the nest dry.\u00a0 The inner lining is made in part of down feathers that the female pulls from her breast.\u00a0 These down feathers create a wonderfully warm place for the eggs.<\/p>\n
The largest nests in Maine are made by birds of prey.\u00a0 An Osprey nest may be five feet across.\u00a0 The outer portion is made of sticks and miscellaneous debris.\u00a0 The inner lining is made of smaller twigs, grasses and other soft material.<\/p>\n
Bald Eagle nests are larger yet.\u00a0 Some nests may be eight feet in diameter and 12 feet high, weighting over a ton!\u00a0 Like Ospreys, Bald Eagles use the same nests year after year, adding material to the nest each spring.<\/p>\n