Bay Nature magazineSummer 2008

Wildlife

The Battle of the Bulge

July 1, 2008

Snakes are famous for the amount of food they can stuff inside their skinny bodies. It’s common for a snake digesting a mouse or other prey to have an unsightly bulge marking the location of the meal. A snake’s lack of a sternum allows its stomach to expand as far as muscle and skin will stretch.

Even so, that doesn’t explain how a snake-eating snake can squeeze in prey longer than its own stomach. To observe this feat, researchers took X-rays of kingsnakes in the act of swallowing corn snakes. They discovered that the swallower uses a combination of jaw ratcheting and body movements to compact the body of the swallowee into a series of bends. Meanwhile, the stomach and esophagus stretch toward the cloaca, or anal opening. Within two weeks, all traces of the hapless corn snake will vanish.

About the Author

Kathleen M. Wong is a science writer based in Oakland.

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