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.

'With the Wild Things' is produced at the Whitaker Center in the College of Arts and Sciences at Florida Gulf Coast University. For 'The Wild Things', I'm Dr. Jerry Jackson.



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