Article snippet: Owls’ are spherical, hummingbirds’ are elliptical and sandpipers’ are pointy. All bird eggs have the same function — to protect and nourish a growing chick. But they come in a brilliant array of shapes. This variety has puzzled biologists for centuries. Now, in the most comprehensive study of egg shapes to date, published Thursday in Science, a team of scientists seems to have found an answer. The researchers cataloged the natural variation of egg shapes across 1,400 bird species, created a mathematical model to explain that variation, and then looked for connections between egg shape and many key traits of birds. On a global scale, the authors found, one of the best predictors of egg shape is flight ability, with strong fliers tending to lay long or pointy eggs. “This paper is remarkable because it creates a wonderfully unified theory for the variety of egg shapes we see in nature,” said Claire Spottiswoode, a bird ecologist at the University of Cambridge and the University of Cape Town who did not participate in the research. In the new study, the authors conducted a multistep investigation that brought together biology, computer science, mathematics and physics. They first wrote a computer program, named Eggxtractor — who says scientists have no sense of humor? —, that classified eggs based on their ellipticity and asymmetry. Elliptical eggs are elongated and round on both ends, like cucumbers, and asymmetric eggs are pointier on one end, like mangoes. With Eg... Link to the full article to read more
Why Do Bird Eggs Have Different Shapes? Look to the Wings - The New York Times
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