Depth/Distance Perception in Gerbils and Spiny Mice: Ecological Considerations

Adult and young gerbils and spiny mice were tested for their ability to discriminate between a short and a long arm in a T-maze. Animals were given 20 training trials/day for 5 days. The gerbils' performance improved from about 45% correct responses on Day 1 to about 80% on Day 5; the performances of the spiny mice stayed at about 40-50% over the training period. There were no age differences. These findings complement those of an earlier study in which spiny mice did demonstrate depth perception on a visual cliff while the gerbils did not. Both sets of data are interpreted from an evolutionary perspective which relates depth perception ability to the organism's natural ecological niche: gerbils are burrowing animals and spiny mice are surface and rock dwellers