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CAS Professor’s Frog Research Makes the Big Time

Karen Warkentin’s research on frog embryos was featured in National Geographic and USA Today.

Good vibrations? Not this time. Among the research of Karen Warkentin, an assistant professor of biology in the College of Arts and Sciences, is the effects of bad vibrations on red-eyed tree frog embryos in the jungles of Panama. She found that the embryos, tucked away in jelly-like eggs on pond leaves, can sense predatory attacks and hatch early to escape — a phenomenon she calls “escape hatching.” Warkentin’s groundbreaking discovery was featured in November in both National Geographic and USA Today.

Warkentin used an electrodynamic shaker — a device that applies sound and movement to an egg — to test the embryos’ response to dangerous recordings of snake attacks, as well as to harmless vibration recordings of rainstorms. The embryos hatched more often in response to predatory snake recordings, suggesting they actually can distinguish between different types of vibrations.

“It was already known that some embryos timed their hatching in response to changes in the physical environment; specifically, some terrestrial eggs of fishes and amphibians hatch when they are flooded,” Warkentin says. “But in general, ecologists and behaviorists didn’t think about eggs as ‘doing’ much besides simply developing to get ready for life after hatching. The discovery that eggs respond to predators changed this.”