الاثنين، 21 ديسمبر 2015

Examples of Nests and Eggs

Examples of Nests and Eggs

Identifying birds' nests can often be very tricky. Many bird species can build very similar nests, thus making identification possible only if you see the adult. However, some species build nests that are quite obvious. The images and information below should help you to identify some of the more common nesting species, even some of the confusing ones. All images are copyright of NestWatch and our participants.

Please click on an image thumbnail to see it larger.  

American Kestrel
Kestrels can be found in a variety of habitats. Preferred areas can include forest edges, orchards, pastures, and even deserts. 
Kestrels may use several different sites for nesting. Natural tree cavities, nest boxes, or crevices in cliffs, dirt banks, or even buildings may be utilized.
Kestrels typically have some height to their nests. Thus, they can be found nesting up to 30 feet off the ground.
Kestrel chicks are semi-altricial at hatching. This means that they are covered with down but are relatively immobile. The chicks typically fledge at 30 days. 
American Robin
Robin nests are usually located in the fork of a bush or tree. However, robins will often nest close to humans on building ledges or other well supported sites.
The nest is an open cup of grass and twigs held together with a thick layer of mud. It is lined with fine dry grass. 
Robins have a very characteristic egg that is usually light blue in color.
Robin chicks are altricial at hatching. This means they have no feathers and are mostly immobile. They completely rely on the adults to survive. 
Barn Swallow
Barn Swallows often breed in a variety of habitats though they particularly prefer being near water and in open country.
Their nest is a shallow cup of mud pellets mixed with grass and hair. It is attached to a vertical surface and can have very little support underneath. 
Barn Swallow eggs are white and sparingly pocked by reddish-brown, violet, or gray spots.
The chicks only have a little gray down on the head and back at hatching. The rest of the feathers develop in the 17 days the chicks spend in the nest.
Black-capped Chickadee
Black-capped Chickadees prefer nesting in forested areas that have plenty of cavities available for nesting.
The chickadee nest has a moss base and is lined with fine materials such as animal fur.
Chickadees usually lay six to eight white eggs that are finely spotted.
The chicks are attentively cared for by both parents. They will be ready to fledge at around 16 days old.
Brown-headed Cowbird
Cowbirds are a generalist species that can breed in a wide range of habitats, including farmland, forest edge, and suburban areas. 
Cowbirds do not build their own nests. Instead, they lay their eggs in the nests of other birds. 
Cowbird eggs can come in a variety of colors. They can be white, blue, or green and most will have some amount of speckling. 
Cowbird chicks are typically larger than the chicks of the host species. This triggers the adults to feed the cowbird chick more, thus allowing the chick to grow faster. 
Carolina Chickadee
Like the Black-Capped Chickadee, Carolina Chickadees typically nest is forested habitat. However, they tend to prefer deciduous forests over coniferous. 
These small birds typically nest in woodpecker holes and other natural cavities. They will also readily utilize nest boxes and artificial cavities. 
Both adults will excavate the nest site and then build a plush nest of moss, plant fiber, hair, and even feathers.
The Carolina Chickadee lays, on average, 6 eggs that are white with fine speckles. The altricial chicks hatch after 14 days of incubation.
Canada Goose
A Canada Goose nest, usually placed close to water, is nothing more than a structure built with plant material and lined with plant down and feathers. 
The nest is usually found on the ground. However, it can occasionally be found on raised locations such as rock ledges, tree stumps, or this house.
Canada Geese lay about 6 large, white eggs. The chicks are precocial, meaning they are covered in down, can walk, and can feed themselves soon after hatching. 
The female incubates the eggs. The male typically acts as a guard and both parents will fiercely defend their eggs and chicks.
Carolina Wren
Though wrens naturally nest in cavities, they adapt well to nest boxes, tree crotches, or human altered surroundings, such as in this potted plant. 
The Carolina Wren nest typically has a nice domed structure to it. The nest itself is made of plant materials and lined with fine grasses, hair, and feathers. 
The eggs are white with speckles that might vary in color from red to purple to gray. Typically, these speckles surround the larger end of the egg.
The young are altricial and downy at hatching. They fledge the nest within 12 to 14 days. 
Eastern Bluebird
Eastern Bluebirds nest in cavities in open woodland, orchards, or meadows. Bird boxes have helped this species, as their natural nesting cavities have become scarce. 
The nest is loosely built of grasses and other plant materials. Finer grasses and sometimes fur are used for the lining. 
Clutch size can range from 3 to 7 eggs, with 5 being the average. The eggs are a pale blue color. Though they can also be white, it is very rare. 
Bluebird chicks can remain in the nest for up to 21 days. However, by 14 days old they can be accurately sexed based on color of the emerging feathers. 
Eastern Phoebe
A good breeding habitat for the Eastern Phoebe could be around farms or other buildings. Cliffs and bridges will also be used as nesting sites. 
The nest is a cup that is composed of mud, moss, and other plant fibers such as grass. It is then lined with finer plant fiber and hair. 
Eastern Phoebes typically build their nests on a ledge, rafter, or a raised site with some overhanging protection. 
Phoebes lay eggs that are smooth white with little to no markings. 
House Finch
Typical breeding habitat for House Finches can be diverse. Preferred habitats are cultivated areas and around buildings, but they may be found in desert, marsh land, or forested habitats. 
The House Finch will utilize a variety of nesting sites. These can include tree branches, cacti, rock ledges, vents, street lamps, hanging planters or in cavities such as nest boxes. 
The nest is built by the female. It is composed of fine grass, leaves, and rootlets. Finer materials such as thread, wool, and feathers are used for the lining. 
House Finch females lay four or five eggs. These eggs are typically a pale blue and can have some very fine black speckles. 
House Sparrow
House Sparrows were introduced to North America. They breed readily around human habitation, especially in cities, and even farms, as there are many crevices for them to nest in.  
The nest is typically a domed structure made of straw, plant stems and trash such as paper, plastic, string, or cloth. It is then lined with finer materials. 
The female lays three to five eggs. They are usually white but can have a blue or green tint. They can also be variably marked with gray, blue, green, black, brown, or purple spots. 
House Sparrow chicks are altricial and naked when they hatch. They grow fast as it only takes about 15 days for the chicks to fledge the nest.  
Hummingbirds
Though most hummingbird species nest in a variety of wooded habitats, many will nest near human habitation. 
The nest is typically a tight cup that saddles the nest site. Nest sites can consist of trees, shrubs, or other horizontal surfaces. 
Nest cups might be made of several materials. Fine plant material is held together with spider silk and lined with even finer material. Then the outside of the nest may be covered with moss or lichen. 
The eggs are typically white and only a few millimeters in diameter. When the chicks hatch, they are altricial, naked, and often no bigger than a small fingernail. 
Mourning Dove
The Mourning Dove breeds over a wide range of habitats. Open woodland, cultivated areas, and suburban gardens all may be home to populations of this species. 
The nest is often little more than a small pile of twigs. Finer grasses may also be used to line the nest. 
Mourning Doves might put their nest on any platform that seems to fit; especially around a building where planters, unused grills, and ashtrays are all suitable sites. 
The female lays only two eggs. They are smooth and glossy white. Though she only lays two eggs, the female may have up to four nesting clutches in a single nesting season. 
Northern Cardinal
The Northern Cardinal breeds over a wide range of habitats. Over-grown clearings, woodland edges, and rural neighborhoods seem to be the most popular. 
The nest is a cup of thin twigs, stems, bark, vines, and roots. Dead leaves, rags, paper, and other fine material might be used in the nest or the lining.  
Cardinals are usually predictable in the placement of their nests. They can almost always be found in shrubs or vine tangles 4 to 6 feet off the ground.
Cardinal eggs are smooth and glossy white or pale green. They have gray, brown, or reddish speckling throughout, which is usually more dense along the larger end. 
Northern Mockingbird
Open woodland with scattered trees and bushes is generally the preferred nesting habitat of the Northern Mockingbird. But shade trees, shrubbery, and plantings around buildings work well. 
Mockingbird nests are a bulky cup of dead twigs. They may even include thorny grasses, decayed leaves, rags, and other detritus. They are lined with finer grasses and occasionally hair. 
The nest itself can be found in a small tree, vine tangle, or a thicket of bushes. It is generally only placed three to ten feet off the ground. 
The eggs are often pale blue or green. They are blotched with reddish speckling that concentrates at the larger end of the egg. 
Other
We are unsure who this nest belongs to. There are either two Eastern Bluebird eggs in a Tree Swallow nest, or four Tree Swallow eggs in an Eastern Bluebird nest. If the nest is being well tended to, all the eggs may hatch. 
This nest box had three interested species. A House Wren started with sticks. Then, a chickadee filled the middle of the box with moss. Finally, an Eastern Bluebird topped the box off with some grass.
There is one bluebird chick in this Tree Swallow nest. When this happens, the Tree Swallows may care for the strange chick as one of their own. Since bluebirds and swallows have similar diets, it may actually work well. 

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