Instrumental discrimination: Reversal learning in the monotreme Tachyglossus aculeatus setosus

Tasmanian echidnas, Tachyglossus aculeatus setosus, were tested in serial discrimination-reversal tasks, comparing their operant behaviour in reversal-shift and non-reversal-shift conditions, using positional and visual/tactile cues. Learning-set formation of the pattern characteristic of eutherian mammals was observed in all tests for all subjects, but performances were superior in tests of positional discrimination and in reversal-shift conditions. The results were consistent with those obtainable for eutherian mammals in comparable tests and suggest that echidnas can be used as subjects in experimental studies of operant learning.