Pawedness and motor asymmetries in toads

Area of Science:

• Ethology
• Comparative Psychology
• Evolutionary Biology

Background:

• Animal behavior studies often investigate lateralization, or preferential use of one body side.
• Understanding limb preference in amphibians provides insights into the evolution of motor control.

Purpose of the Study:

• To investigate pawedness (limb preference) in three toad species: Bufo bufo, Bufo viridis, and Bufo marinus.
• To determine if limb laterality is present and consistent across different tasks and species.
• To infer the evolutionary history of preferential limb use.

Main Methods:

• Behavioral tests were conducted on toads from natural populations over two years.
• Tasks included removing a paper strip from the snout and an elastic band from the head.
• A righting response test (rotation when on the back underwater) was used for Bufo marinus.

Main Results:

• Bufo bufo exhibited a population-level preference for the right forelimb in both snout and head-based tests.
• Bufo viridis showed no clear pawedness.
• Bufo marinus displayed no laterality in the paper-strip test but was strongly lateralized in the righting response test, using the right forelimb.

Conclusions:

• Preferential limb use (laterality) is present in some toad species, with Bufo bufo showing a consistent bias.
• The findings suggest that limb preference has deep evolutionary roots, potentially dating back to early tetrapods.
• Amphibian laterality offers a model for studying the evolution of motor control and brain lateralization.