A new paper adds another animal to the list of pathfinders, and it’s this little guy here:
This is a poison dart frog (Allobates femoralis). We normally don’t think of amphibians as animals that travel great distance, but this species has complicated territorial behaviour. The frogs defend a territory that is is about 14 meters across, which is pretty large compared to their body size. This led Pašukonisand and colleagues to test whether this frog could find its way around in its natural habitat.
The experimenters “translocated” a bunch of male frogs from their territories to new locations. To these frogs, this is probably what the scientists seemed like:
Translocation is basically the scientific equivalent of stuffing you in a car trunk, driving around for a few hours, then letting you out in the middle of the nowhere and telling you that you’re walking home.
The frogs were moved anywhere from 50 to 800 meters. The frogs performed very well for distances up to 200 meters: 87% of them made the long walk back to their original territory. At 400 meters, only about a third of the frogs got home, and none made it back from 800 meters.
The authors looked at a few other variables, like the directions the frogs were moved, the presence of streams or rivers between the catch and release sites, but distance was the only factor that predicted whether the frogs found their way home. The authors also think that the failure of the frogs to get back from the long distances is not likely to be due to things like exhaustion or predation. The frigs can go quite long distances, and because they are poison dart frogs, predation seems low.
How do these frogs do this? There are many ways that animals can navigate, from simply learning the local area very well (fails if you move to a new place) to true navigation (where you can find your way back from anywhere). Trying to sort out the mechanism the frogs are using to get back to their favourite spot is surely one of the next logical experiments to do, although the authors seem to favour the “know the locale really well” hypothesis.
Maybe the frogs have ruby flippers. “There’s no place like (croak) home.”
Pašukonis A, Ringler M., Brandl HB, Mangione R, Ringler E, Hödl W, Tregenza T. 2013. The homing frog: high homing performance in a territorial dendrobatid frog (Dendrobatidae). Ethology: in press. DOI: 10.1111/eth.12116
Photo by Sean McCann (ibycter.com) on Flickr; used under a Creative Commons license.