How bird skeletons can look so delicate and still be heavy

Washington, March 21 (ANI): A scientist has explained how bird skeletons can look so delicate and still be heavy.

The scientist in question is modern bat researcher, Elizabeth Dumont of the University of Massachusetts Amherst.

In her research, Dumont determined that bird bones are denser than mammal bones, which makes them heavy even though they are thin and sometimes even hollow.

According to Dumont, "The fact that bird bones are denser than bones in mammals not only makes them heavier for their size, but it may also make them stiffer and stronger."

"This is a new way to think about how bird skeletons are specialized for flying and solves the riddle of why bird skeletons appear so lightweight and are still relatively heavy. This has never been explained fully and so has never gotten into the textbooks. I'd like to see that change," she said.

Dumont measured the density of the cranium, the upper arm bone or humerus and the thigh or femur bones in song birds, rodents and bats by measuring bone mass and volume.

"I found that, on average, these bones are densest in birds, followed closely by bats. Many other studies have shown that as bone density increases, so do bone stiffness and strength," she said.

"Maximizing stiffness and strength relative to weight are optimization strategies that are used in the design of strong and stiff but lightweight man-made airframes," she pointed out.

"Over time bird bones have evolved specializations that maximize stiffness and strength," Dumont said.

These specializations include high bone density, a reduction in the total number of bones, fusion of some bones, and changes in bone shape.

Dumont's new data may help to dispel the common misconception that bird skeletons are lightweight relative to body mass.

Instead, bird and bat skeletons only appear to be slender and delicate because while they are dense, they are also heavy.

Being dense, strong and stiff is one more way that birds' and bats' bones are specialized for flight. (ANI)