Sunday, June 24, 2007
Sunday, June 17, 2007
Great Egret
Elkhorn Slough. June 17, 2007
Notes
Formerly known as the "American Egret," "Common Egret," "Large Egret," "White Egret," "Great White Egret," and "Great White Heron," this bird's official name in North America is now Great Egret. One of the most magnificent of our herons, it has fortunately recovered from historic persecution by plume hunters. But it is still not out of danger: The destruction of wetlands, especially in the West where colonies are few and widely scattered, poses a current threat to these majestic birds. Like the Great Blue Heron, it usually feeds alone, stalking fish, frogs, snakes, and crayfish in shallow water. Each summer many individuals, especially young ones, wander far north of the breeding grounds.
Formerly known as the "American Egret," "Common Egret," "Large Egret," "White Egret," "Great White Egret," and "Great White Heron," this bird's official name in North America is now Great Egret. One of the most magnificent of our herons, it has fortunately recovered from historic persecution by plume hunters. But it is still not out of danger: The destruction of wetlands, especially in the West where colonies are few and widely scattered, poses a current threat to these majestic birds. Like the Great Blue Heron, it usually feeds alone, stalking fish, frogs, snakes, and crayfish in shallow water. Each summer many individuals, especially young ones, wander far north of the breeding grounds.
Snowy Egret
Elkhorn Slough. June 17, 2007
Notes
These delicate, agile birds often feed by sprinting rapidly through shallow water, chasing schools of minnows and shrimp. This habit makes them easy to identify without seeing their bills and feet. Often several Snowies will be found feeding together, and it is thought that their white color, visible at great distances, lets other birds know where the feeding is good; the sprinting behavior also attracts other birds that then join in the feast. There is evidence that members of a pair of Snowy Egrets, like other large waders, cannot recognize one another except at the nest. Even there, a bird arriving to relieve its mate must perform an elaborate greeting ceremony in order to avoid being attacked as an intruder. During this display the plumes on the head are raised and the incoming bird bows to the one that is sitting. Appeased by this display, the sitting bird leaves and the other takes over.
These delicate, agile birds often feed by sprinting rapidly through shallow water, chasing schools of minnows and shrimp. This habit makes them easy to identify without seeing their bills and feet. Often several Snowies will be found feeding together, and it is thought that their white color, visible at great distances, lets other birds know where the feeding is good; the sprinting behavior also attracts other birds that then join in the feast. There is evidence that members of a pair of Snowy Egrets, like other large waders, cannot recognize one another except at the nest. Even there, a bird arriving to relieve its mate must perform an elaborate greeting ceremony in order to avoid being attacked as an intruder. During this display the plumes on the head are raised and the incoming bird bows to the one that is sitting. Appeased by this display, the sitting bird leaves and the other takes over.
Friday, June 15, 2007
Friday, June 8, 2007
Sunday, June 3, 2007
Friday, June 1, 2007
American Crow
Asilomar State Beach. June 1, 2007
Adult American crows are completely black birds weighing on average 450 g. The feathers have a glossy and slightly iridescent look. Crows have strong legs and toes. The bill is also black with a slight hook on the end. Stiff bristles cover their nostrils. About 20% of male birds are slightly larger than the females.
Young crows are about the same size as adults, but have blue eyes and pink inside the mouth. Both the eyes and mouth darken as the bird becomes an adult. In young birds, the ends of tail feathers are symmetrical and are more pointed than the wide, flat-ended feathers of adults. The wing and tail feathers of the young can become quite brown and ragged through the first winter and spring and only become darker and more glossy like adult feathers after the first molt.
American crows are often confused with common ravens. American crows can be distinguished from common ravens (Corvus corax) most easily by size (ravens are much larger), by voice (ravens are hoarser), by the bill (ravens have heavier, "roman-nosed" bills), and by the shape of the wings and tails, which come to a point in ravens but not crows.
More Details:
http://animaldiversity.ummz.umich.edu/site/accounts/information/Corvus_brachyrhynchos.html
Young crows are about the same size as adults, but have blue eyes and pink inside the mouth. Both the eyes and mouth darken as the bird becomes an adult. In young birds, the ends of tail feathers are symmetrical and are more pointed than the wide, flat-ended feathers of adults. The wing and tail feathers of the young can become quite brown and ragged through the first winter and spring and only become darker and more glossy like adult feathers after the first molt.
American crows are often confused with common ravens. American crows can be distinguished from common ravens (Corvus corax) most easily by size (ravens are much larger), by voice (ravens are hoarser), by the bill (ravens have heavier, "roman-nosed" bills), and by the shape of the wings and tails, which come to a point in ravens but not crows.
More Details:
http://animaldiversity.ummz.umich.edu/site/accounts/information/Corvus_brachyrhynchos.html
Brewer's Blackbird (male)
My backyard in Salinas. June 1, 2007
Brewer's Blackbirds are colonial nesters that sometimes practice polygamy when a surplus of females are available. Even so, primary pairs are formed. They reunite each spring after spending the winter separately in migrating flocks.
More Details
http://www.birds.cornell.edu/BOW/BREBLA/
More Details
http://www.birds.cornell.edu/BOW/BREBLA/
Thursday, May 31, 2007
Wednesday, May 30, 2007
House Finch (male)
Through my office window. (April 24, 2007)
House Finch
Carpodacus Mexicanus
A bright red and brown-striped bird of the cities and suburbs, the House Finch comes readily to feeders. It also breeds in close association with people, and often chooses a hanging plant in which to put its nest.
Cool Facts:
More Details:
http://www.birds.cornell.edu/AllAboutBirds/BirdGuide/House_Finch.html
Carpodacus Mexicanus
A bright red and brown-striped bird of the cities and suburbs, the House Finch comes readily to feeders. It also breeds in close association with people, and often chooses a hanging plant in which to put its nest.
Cool Facts:
- The House Finch was originally a bird of the southwestern United States and Mexico. In 1940 a small number of finches were turned loose on Long Island, New York, and they quickly started breeding. They spread across the entire eastern United States and southern Canada within the next 50 years.
- The red or yellow color of a male House Finch comes from pigments that it gets in its food during molt. The more pigment in the food, the redder the male. Females prefer to mate with the reddest male they can find, perhaps assuring that they get a capable male who can find enough food to feed the nestlings.
- When nestling House Finches defecate, the feces are contained in a membranous sac, as in most birds. The parents eat the fecal sacs of the nestlings for about the first five days. In most songbird species, when the parents stop eating the sacs, they carry the sacs away and dispose of them. But House Finch parents do not remove them, and the sacs accumulate around the rim of the nest.
More Details:
http://www.birds.cornell.edu/AllAboutBirds/BirdGuide/House_Finch.html
Sunday, May 27, 2007
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