The time for nest-building has arrived for Black-capped Chickadees. They most often choose dead aspens and birches as nesting trees, and the punkier the wood the better so that the birds can easily excavate a cavity with their small beaks. While both male and female create the nest hole, the female builds the nest within the cavity by herself.
Most chickadee nests are used only once, and consist of coarse material such as moss for the foundation and finer, softer material such as the hair of rabbits or deer for the lining. The pictured chickadee is only a day or two away from laying eggs, for she is collecting shed fur from red fox kits (they grow three different coats on their way to maturity – gray, sand-colored and red) for the lining of her nest. She found a bonanza of nesting material on the dirt mound at the entrance of an active fox den, where the kits spend much of their time. (Thanks to Jim Block for photo op.)
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.
Although male Baltimore Orioles have been known to partake in nest building, usually it’s the female who selects the specific site within the male’s territory and builds the nest. Located at the tip of a slender branch, this pendulous nest provides its occupants with as much protection from predators as is possible.
The material with which the nest is started usually consists of flexible plant, animal or human-made fibers, and provides support. “Springy” fibers are then woven into the inner bowl and downy fibers are used to line the nest. The oriole usually brings only a single fiber at each visit, and works it into the nest with a complex series of bill-weaving techniques. The nest is completed in roughly one week.
Construction material includes hair (especially horsehair), twine or string, wool, synthetic fibers (one oriole nest was made entirely of cellophane), various types of plant fibers including grasses, milkweed stems and grapevine bark, cottonwood or willow seed “cotton,” milkweed seed plumes and feathers. Females have been observed flying more than a quarter of a mile in search of construction material. (Photo: Female Baltimore Oriole on her first day of nest-building)
YESTERDAY’S MYSTERY PHOTO: Once again, Naturally Curious readers outdid themselves with creative solutions to a Mystery Photo. If you want a thoroughly enjoyable 5 minutes of entertainment, read yesterday’s comments! I will let you know if this mystery is ever solved.
When eagle chicks hatch they are covered with light gray down and have brown eyes and pink legs. One parent, usually the female, spends most of the day in the nest with her young for the first three weeks, brooding and keeping them warm. The male provides most of the food during this time. After he delivers prey, she tears off small pieces and feeds them to the nestlings. The chicks gain weight rapidly – roughly ¼ pound a day – so that in three or four short weeks the young are nearly the size of an adult. Eaglets are roughly six weeks old before they are capable of tearing off food and feeding themselves, and at least eight weeks old before they leave the nest. (Note corn stalk that’s been incorporated into nest; photo: one-week-old eaglet & its mother)
In the Northeast, Bald Eagles seek out the tallest trees around in which to build their nests. In certain locations in Alaska, coastal California and northern Canada where there are no trees, Bald Eagles will nest on the ground. When building a nest in a tree, eagles will usually build it in the top quarter of the tree, just below the crown, on limbs capable of supporting a large nest. Sticks from the ground are collected up to a mile away from the nest or are broken off of nearby trees. Additional materials are regularly added to the nest throughout the year, including daily additions during the breeding season (see photo).
Many live eagle cams can be found online (in Minnesota, one chick, one egg – http://mnbound.com/live-eagle-cam/ ; in Georgia, older nestlings: http://www.berry.edu/eaglecam/ ; in Pennsylvania, very young chicks: http://www.ustream.tv/decoraheagles ), giving the viewer a window into the incubation, birth and growth of these raptors. Depending on the location of the nest, one can see every stage of development, from eggs to hatchlings to all-but-fledged nestlings. In New England, eggs are soon to hatch, if they haven’t already. (Thanks to Marianne Blake for photo op.)
Great Horned Owls are said to have the widest range of nest sites of any bird in North or South America. Like other owls and falcons, this raptor does not build its own nest, but rather relies heavily on abandoned stick nests of diurnal birds of prey. Red-tailed Hawk nests are often usurped, as well as those of Bald Eagles, crows, ravens and herons. Nests may be lined with shreds of bark, leaves, downy feathers from the owl’s breast, fur of prey and trampled pellets. In addition to bird nests, Great Horned Owls also raise their one to four nestlings (usually two) in tree cavities and snags, on cliffs, in deserted buildings, in squirrel nests and even on the ground.
The female Great Horned Owl does all the incubating; the male delivers prey to her at intervals throughout the night. These early nesters have incubated eggs successfully when outside temperatures have been as low as -27°F. Hopefully warmer temperatures will welcome the newly hatched owlets in about a month. (photo: mostly hidden Great Horned Owl in Great Blue Heron nest)
At least two to four weeks before one would expect to find a black-capped chickadee building a nest, one was busily collecting hairs shed by my chocolate lab yesterday. In addition to fur, chickadees line their nest with grass (not available yet here), down and moss (hard to come by with two feet of snow still on the ground). Chickadees are able to nest this early in part because they nest in cavities, which offer them protection from the elements. Not having bills strong enough to hammer out cavities in living trees, chickadees rely heavily on rotting stumps for nest sites — the wood in them is punky and easy to remove. Birch, poplar and sugar maple snags and stumps are preferred nesting trees. If you want to provide chickadees and other birds with nesting material, take advantage of the fact that dogs and cats are shedding now, and recycle their fur.