"Physiology has a really critical role in species preservation and we think we've underplayed that," Williams said. Physiologists can define the daily and seasonal energy needs of these animals, information that help protect big, fierce animals.

In particular, Williams will look at marine animals, which live a relatively expensive lifestyle in terms of the energy they expend. Generally, they consume twice as many calories as carnivorous land animals of similar size. Killer whales, for example, consume 200,000 calories per day. Information about bioenergetics can be used to preserve these species, for example by creating marine reserves where human hunting and fishing is limited.

Williams is the author of "Hunter's Breath," a book about her research in Antarctica on the Weddell seal. She was named one of the top 50 women scientists in 2002 by Discover magazine.

Hear Williams speak on Tuesday, Oct. 10. Her talk is embargoed until 3 p.m.

• Carlos Martinez del Rio, University of Wyoming

Hummingbirds live in the fast lane, but this pedal-to-the-metal lifestyle requires their little bodies to deliver enough fuel to stay ahead of the crowd. These remarkable birds can shut down their kidneys, a feat that would kill a human being, Martinez del Rio has found. His talk is entitled "The comparative/ecological physiology of nectar-feeding birds: the last 15 years."

Hummingbirds get their energy from sugar found in nectar. But nectar is mostly water, so the birds need to consume a lot of it to get enough sugar. Their kidneys must get rid of all that water by filtering it very fast. But because they have a very high respiration rate, they must conserve water when they are not feeding, or they will be
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Contact: Christine Guilfoy
cguilfoy@the-aps.org
301-634-7253
American Physiological Society
11-Sep-2006