2008 Woodie Awards
ISU professor studies male behavior of Puerta Rican frog
Eryn Lowe
Issue date: 4/13/05 Section: News
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Ten Eyck, who previous to ISU was a research scientist at the University of Michigan, has been studying the frog, the Puerto Rican Coqul, Eleutherodactylus coqui, for 10 years. Ten Eyck said this frog, found primarily in Puerto Rico, has different parental habits than most other amphibians--particularly in the male's behavior. After mating, the eggs are instantly guarded by the male parent. The female leaves while the male continues to sit and literally cling to the eggs for up to two and a half weeks.
Ten Eyck said there are three stages in which the male frog transitions through. The first is the paternal male where the frog is aggressive for eggs for food.
The second is territorial where the male is aggressive, but he is aggressively guarding his own eggs from other frogs who will try to eat them. Ten Eyck demonstrated this defense by a test he and his students performed. They placed a speaker and two fake frogs on either side of a territorial frog with his eggs. They played the call of a paternal or satellite frog through the speaker. Instead of going for the model frogs on either side of him, this frog literally attacked the speaker as he seemed "stressed" by it. In another demonstration involving an actual paternal and territorial frog, the territorial father attacked the paternal frog-who got to close- and held him in his mouth for 45 minutes.
The third is the satellite male who basically, as Ten Eyck put it, "hangs out" around the others.
These frogs will make various calls to each other. The territorial frog will give calls to the paternal and satellite males warning them to get away and also calls to females for mating. The study and question for Ten Eyck and his students is the actual transition the male frog goes through from one stage to another. Once a satellite male mates, he becomes aggressive and protective of his eggs--becoming a territorial male. After the two weeks of continual defense and the eggs hatch into "froglets," the male will continue to guard these tiny newborn frogs for another four to five days without eating them (another "wonder" in the amphibian world). Once the froglets hop off on their own, their territorial father will then also hop off, but he is now a paternal male as he "aggressively" looks for eggs and crickets for food.