“It caught us off guard,” Dr. Pasukonis said, that behavior which seemed that it might require several actions to trigger it, such as breeding and the presence of eggs or tadpoles in the right place, could be initiated by one simple event.
“Once the tadpoles are on the back, the rule is to go transport them,” Dr. Pasukonis said.
“I’m still surprised that it actually works.” But, he said, the signal that tells the frogs to move is clear and simple. “Tadpoles on the back — you have to go.”
Dr. Pasukonis and Ms. Beck worked on the two projects with Eva Ringler and Max Ringler, both of the University of Vienna, using a small river island with both natural pools and man made pools. They lived in huts at a French research station, which had unexpected benefits.
“We get frozen food,” Dr. Pasukonis said, “but it will include five types of cheese as well, so you feel that you’re in France.”
Tracking inch-long frogs up to a couple of hundred yards in dense vegetation, sometimes over a day or more, was not an easy task. They first had to catch frogs, and then equip them with transponders attached to tiny silicon waistbands.
The finding that tadpole transport was a fully developed behavior in both males and females, even though males did it almost exclusively in nature, was another significant part of the research, said Dr. Pasukonis.
He said the study of complex behavior in amphibians is in its infancy, and hopes to perhaps delve into the underlying neuroscience.