Thursday, March 6, 2008

Bats: New, Old and Blue

Bats have invaded the news.

One group of researchers reported how bats stay aloft as they fly slowly or hover. The downward strokes of their wings produce small cyclones of air that pull the animals upward. (Photo and video of Pallas’ long-tongued bat at a feeder in wind tunnel.)

video

Another group reported that analysis of a 52-million-year-old bat fossil (photo) -- the most primitive bat known -- revealed that bats learned to fly before they developed their internal “sonar” to navigate.

Still another group reported the discovery of six new bat species dating back 35 million years. The species were found among fossils that had been unearthed over several decades in an oasis region southwest of Cairo, Egypt. They are called the best evidence yet that modern bats evolved in Africa rather than in the Northern Hemisphere, as sometimes theorized.

The fossils were collected by Duke paleontologist Elwyn Simons (photo), who has been digging in that region since the 1960s. He is best known for discovering fossils of numerous new primate species that speak to the evolution of the first anthropoid ancestor of monkeys, apes and humans. Glimpses of his work are here and here.

Bats also turn up in other Duke research. For example:

Xuejun Liao of the department of electrical and computer engineering says the way bats approach their bug targets -- in zigzag routes, transmitting and receiving sound waves at multiple frequencies -- holds lessons for designing planning strategies for artificial-intelligence systems.

A team of mechanical engineers led by Adrian Bejan has developed a single unifying physics theory that can essentially describe how animals of every ilk -- bats that fly, fish that swim, humans that walk -- get around.

And undergraduate students in the Nicholas School of the Environment and Earth Sciences have assessed the impact of wind turbines on bat and bird populations.

Bats -- who wudda thunk?