Numerous previous investigators have explained species differences in spatial memory performance in terms of differences in foraging ecology. In three experiments we attempted to extend these findings by examining the extent to which the spatial memory performance of echidnas (or "spiny anteaters") can be understood in terms of the spatio-temporal distribution of their prey (ants and termites). This is a species and a foraging situation that have not been examined in this way before. Echidnas were better able to learn to avoid a previously rewarding location (to "win-shift") than to learn to return to a previously rewarding location (to "win-stay"), at short retention intervals, but were unable to learn either of these strategies at retention intervals of 90 min. The short retention interval results support the ecological hypothesis, but the long retention interval results do not.
Echidnas have evolved separately from other mammalian groups for around 200 million years and incorporate a mixture of reptilian and mammalian features. Because of these attributes, they have historically been considered "primitive" animals. However, they have successfully adapted to a wide variety of ecological niches and their neurophysiology demonstrates a number of unusual and apparently sophisticated characteristics, including a relatively large brain and cerebral cortex and a comparatively massive frontal cortex. Studies of learning in the echidna have thus far been limited to only a handful of experiments which demonstrated relatively basic abilities such as forming a position habit in a T-maze, successive habit-reversal learning, and simple visual and instrumental discrimination. This study aimed to expand on these results and test the "primitive" echidna on what are generally considered more advanced cognitive tasks-same/different and conditional same/different concept learning. The results demonstrated that echidnas are able to discriminate on the basis of a relational same/different concept, using simultaneously presented multi-element stimuli, and transfer that discrimination to novel stimuli. After further training, they were then able to repeat the performance when the correct choice was conditional on the background color of the stimulus panels.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.