Rain forest navigators: the role of learning in spatial behavior of poison frogsEin Vortrag von ANDRIUS PAŠUKONIS & WALTER HÖDL
Spatial learning has been studied in a variety of mammals, birds and insects, and has become one of the most comparative topics in animal cognition. However, ectothermic vertebrates, especially amphibians, have been highly neglected in this research area, at least in part because they were not considered to have advanced learning abilities.
At the same time, directed long distance movements, such as mass spring migration to breeding ponds in temperate-region amphibians, have drawn attention to amphibian orientation mechanisms. Several authors have suggested that amphibians might use learned local cues to find their way around but empirical evidence is lacking. Furthermore, orientation and navigation have been studied almost exclusively in temperate regions, while some of the most complex spatial behaviors (e.g., territoriality and tadpole transport) are found in tropical amphibians, such as the poison frogs (Dendrobatidae).
We investigated the movement patterns and orientation mechanism of two territorial dendrobatid frogs with paternal tadpole transport. We experimentally displaced males from their territories and manipulated artificial tadpole deposition sites in the field. We quantified movement patterns by telemetry and extensive field observations. We found that males of Allobates femoralis return to their home territories by a nearly straight line from several hundred meters but only from areas that have potentially been explored during their lifetimes. We also found that tadpole-transporting A. femoralis males arrive to the exact locations of the deposition sites even after the artificial pools have been removed. Finally, we demonstrate that male Ameerega trivittata home from distances two times longer than A. femoralis, an ability most likely linked to their longer natural movements during tadpole transport.
Our results document surprising way-finding abilities of Neotropical poison frogs. We demonstrate that learning plays a major role in their spatial behavior. We suggest that poison frogs form a large-scale spatial map that they use for flexible navigation, but the exact cues being used still remain unknown.
Bibliothek der Herpetologischen Sammlung, Naturhistorisches Museum Wien, Eingang Burgring 7