( Comparative studies of captive breeding...)Costly breeding programs for endangered species pay off

Worldwide, zoos spend millions of dollars each year transporting rare animals thousands of miles in order to breed them with their most distantly related relatives. Some have questioned the need for such programs, which can stress rare animals, even to the point of death.

Rice's results, which are available online, are scheduled to appear in an upcoming issue of the journal Zoo Biology. The results are based on a yearlong study of 11 generations of houseflies. The study is the first to compare the so-called "maximum avoidance inbreeding," or MAI strategy, with regimens that allow limited inbreeding.

"In previous studies, a number of groups identified short-term benefits for breeding schemes that used limited inbreeding in order to produce stronger individuals," said Lisa Meffert, assistant professor of ecology and evolutionary biology and the lead researcher on the project. "Ours are the first tests of the long-term consequences of these strategies. In particular, we wanted to simulate several generations of captive breeding followed by several generations of breeding in the wild."

Meffert, post-doctoral researcher Stacey Day, graduate student Sara Hicks and pre-med student Nsuela Mukana found that populations in both breeding groups exhibited similar levels of fitness and fertility as long as they remained in a controlled, "captive" setting. However, after the simulated release into the wild, the MAI populations were less likely to go extinct or to suffer population crashes than were the populations that had undergone limited inbreeding.

"The benefits of maximum-avoidance inbreeding were difficult to detect as long as the populations remained captive," said Meffert. "It's not clear why this is
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Source:Rice University