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- Permanent Link:
- http://dpanther.fiu.edu/dpService/dpPurlService/purl/FI14090827/00001
Notes
- Scope and Content:
- Source: Bird Eggs 1
Length of Segment: 00:01:09
Hi, I'm Dr. Jerry Jackson, out with the wild things. At Easter, we often color eggs and decorate them with fanciful designs, but spring is also the season when nature provides an array of colors and patterns on the eggs of wild birds. In the late-1800s, kids and adults collected bird eggs just as people today collect beanie babies and baseball cards. Magazines provided opportunities for egg collectors to exchange and sell their eggs, and department stores sold cabinets for housing egg collections and special drills for removing the contents of eggs. Some wild birds declined as egg collecting became increasingly popular and by the early 20th century, the collecting of eggs, birds, or disturbing the nests of wild birds was made illegal. Take a quick peek at the sky blue of a bluebird’s eggs, the blue-green rust spotted eggs of the cardinal, or the elaborate squiggles and spots on pale-blue of a grackle's egg. But don't touch; oil from your fingers can plug the tiny pores in the shell that the growing bird inside needs for breathing. Perhaps someday they'll thank you with a song. ( English,English,English,English,English )
- Scope and Content:
- Source: Bird Eggs 2
Length of Segment: 00:01:17
Hi, I'm Dr. Jerry Jackson, out with the wild things. The number of eggs that a bird lays during one nesting effort is called a ‘clutch’. A female is capable of laying only one egg per day, and in some birds that lay large eggs, such as our vultures, there may be two or more days between eggs. Some birds nearly always lay the same number of eggs. Doves, for example, usually lay a clutch of only two eggs, and killdeer almost always lay four eggs. In other birds, the normal clutch size can vary with age of the female, time of the nesting season, and geographic location. Young birds nesting for the first time often lay fewer eggs than older birds. Birds nesting early in the season often lay more eggs than those nesting later. Those birds living close to the equator have smaller average clutches than those distant from the equator. At the equator, there is always twelve hours of daylight and twelve hours of darkness, and birds can only raise as many young as they can provide food for during the short day. Away from the equator, and with more daylight hours, birds can raise more young. By the way, the ancestors of our domestic chickens normally had a clutch size of twelve eggs, which is why we normally buy eggs by the dozen.
- Scope and Content:
- Source: Bird Eggs 3
Length of Segment: 00:01:13
Hi, I'm Dr. Jerry Jackson, out with the wild things. Where do the colors of the eggs of wild birds come from? Why are they colored at all? The primitive color of bird eggs is white like those of reptiles. Owls, woodpeckers, doves, and some chickens still lay white eggs. Other kinds of birds produce eggs of diverse colors and patterns. The colors come from two sources: the blues and greens are pigments that come from the breakdown of bile, a product of liver function. Reds, browns, and black come from the breakdown of red blood cells. Thus, the colors on bird eggs are waste products that birds recycle, putting the waste to a new use. Some eggs have a camouflaging pattern and are safer from predators. Colors and patterns of bird eggs help birds recognize their own eggs, and provide a stimulus for incubation. Among the most beautiful of bird eggs are those of tinamous, chicken-like birds native to Latin America. Each kind of tinamou lays eggs of a different solid color. What's so remarkable about tinamou eggs is their shine; they look like polished jewels. The male does all the work of incubating tinamou eggs, perhaps under the spell of their beauty.
- Scope and Content:
- Source: Bird Eggs 4
Length of Segment: 00:01:11
Hi, I'm Dr. Jerry Jackson, out with the wild things. Most birds lay eggs that are shaped somewhat like chicken eggs: slightly larger at one end and slightly more pointed at the other. As an egg is formed, it's squeezed from behind, pushing it through the female reproductive tract, creating the more pointed end in front. In some birds, the egg is rotated just before laying and laid large end first. Some cliff-nesting seabirds lay an egg that is somewhat pear-shaped, having one very large rounded end and a much smaller pointed end, an exaggeration of the shape of the typical chicken egg. These birds build no nest, but lay their egg on a ledge. The eggs unusual shape means that if it happens to roll, it will roll on a tight circle rather than off the ledge. Hummingbirds and chimney swifts lay eggs that are nearly cylindrical, a sort of stubby cigar shape. Owls lay eggs that are nearly spherical. The killdeer lays eggs that are short but pointed at one end and very large at the other so that the four eggs in clutch fit together like pieces of a jigsaw puzzle. Thus, allowing the birds to produce very large eggs, but ones that they can still cover during incubation.
- Scope and Content:
- Source: Bird Eggs 5
Length of Segment: 00:01:14
Hi, I'm Dr. Jerry Jackson, out with the wild things. Bird eggs vary tremendously in size, reflecting the size of chicks and the extent to which the new hatched chick is developed. Eggs that are relatively large compared to the size of the bird are laid by birds like chickens, ducks, or killdeer whose chicks are capable of moving around and feeding themselves shortly after hatching. The eggs must be large enough to contain all the nutrients needed for the full development of a chick. The incubation period in such birds is long, often nearly a month, to allow for such development. Hummingbirds and many songbirds are so small that they can only lay eggs that are small and contain minimal nutrients. These eggs usually hatch within two weeks, producing helpless chicks that must be fed. Most of their development must take place after the young have hatched. The largest egg laid by any living bird is produced by an ostrich, but this is also the smallest egg laid by a bird relative to the size of the bird. The kiwi hold the record for the laying the largest egg relative to the size of the bird. A female kiwi weighs about four pounds, and she lays an egg that weighs about a pound.
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- Resource Identifier:
- FI00900160
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