Salamanders (Plethodon cinereus) go for more: rudiments of number in an amphibian
Techniques traditionally used in developmental research with infants have been widely used with nonhuman primates in the investigation of comparative cognitive abilities. Recently, researchers have shown that human infants and monkeys select the larger of two numerosities in a spontaneous forced-choice discrimination task. Here we adopt the same method to assess in a series of experiments spontaneous choice of the larger of two numerosities in a species of amphibian, red-backed salamanders (Plethodon cinereus). The findings indicate that salamanders "go for more," just like human babies and monkeys. This rudimentary capacity is a type of numerical discrimination that is spontaneously present in this amphibian.
KeywordsNumerical discrimination Salamander Number
We thank Henry Wilbar for permission to use the facilities at Mountain Lake Biological Station; Don Dedrick, Mike Kalish, and Tony Maida for comments on an earlier version of this manuscript; Danielle Lee for assistance with the experiments; Tom Dickins and Uri Leron for comments on a presentation at the 2002 HBES conference based on these experiments, and three anonymous reviewers for comments on the previously submitted draft. The experiments described here comply with the current laws for animal care and use of the United States and were approved by the Animal Care and Use Committee of the University of Louisiana at Lafayette (IACUC no. 2001-8717-004).
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