|
Birds do it. Bees do it. Even educated fleas do it, wrote Cole Porter. Scientists might quarrel with the idea that animals fall in love, but when it comes to interbreeding, birds do it far more than most researchers suspected, according to a new book by a University of Georgia scientist.
Researchers and bird enthusiasts have long known about hybrids, of course. When an experienced watcher sights a bird that does not completely match any description in a field guide, he or she might conclude it is a hybrid. A hybrid is the offspring of mating between different types—in many cases types so distinct that they are treated as separate species.
But in a new book, Handbook of Avian Hybrids of the World, geneticist Eugene McCarthy shows that many old ideas about hybrids are fading as research peels back an entirely new picture of how these crosses operate in nature.
“Interest in avian hybridization has been steadily rising, especially in the fields of taxonomy, conservation and evolutionary biology,” said McCarthy, a postdoctoral associate in the laboratory of UGA professor Jeffrey Bennetzen. “As it turns out, many avian hybrids are not sterile. The ability of such hybrids to produce offspring has important implications for how we think about natural populations and the origin of new organismal types.”
The book is an extremely detailed listing of known hybrids, with massive documentation. It runs to nearly 600 pages. William S. Moore, a well-known ornithologist and professor of biology at Wayne State University, says the book “seems to come as close to a complete compilation as is humanly possible.” No modern reference on the topic has been available, and yet information on avian hybridization is important for anyone who works with, or takes an interest in, birds.
While increasing knowledge of hybrids has added immensely to the picture of avian species in the past 20 years, rare hybrids are unfortunately mistaken at times for endangered species. For example, McCarthy points out, the Imperial Pheasant in Vietnam was long treated as a species and considered one of the most endangered pheasants in the world, but is now known to be a natural hybrid, the offspring of matings between Edwards’s Pheasant and the Silver Pheasant.
“For many years, animal hybrids were believed to occur only rarely, and even then, primarily in captivity,” said McCarthy. “But avian hybrids cannot be so easily dismissed. Hybrid zones listed in the cross accounts [in the book] occur in virtually every country of the world. In many of these zones, hybrids are produced in huge numbers. Much remains to be learned about hybridization in birds.”
Eugene McCarthy’s new book may be the volume that makes such new studies take wing.
|
At nearly 600 pages, UGA geneticist Eugene McCarthy’s new book is an extremely detailed listing of known avian hybrids. The work shows many old ideas about hybrids are fading as research peels back an entirely new picture of how these crosses operate in nature.
