Unlearned appetite controls: Watersnakes (Nerodia) take smaller meals when they have the choice
Publication Type: |
Journal Article |
Year of Publication: |
2005 |
Authors: |
Paul T. Andreadis, Gordon M. Burghardt |
Publication/Journal: |
Journal of Comparative Psychology |
Keywords: |
appetite, meal size, nerodia, watersnakes |
ISBN: |
1939-2087 0735-7036 |
Abstract:
Studies of appetite in mammals emphasize that meal size is learned, but lactation and parental care constrain testing of naive individuals. Neonatal reptiles, in contrast, are self-sufficient foragers. The authors examined the effect of prey size on meal size in primivorous (at first feeding) northern watersnakes (Nerodia sipedon). When offered an excess of small prey (2%-20% of snake mass), neonates ate significantly smaller meals (M = 23.5% of snake mass) than when offered a single huge item (range = 32%-55%). The authors conclude that (a) the taking of smaller meals is not a learned effect, (b) there may be a satiety threshold for meal size rather than a target, (c) oropharyngeal stimuli may provide satiety cues, and (d) huge meals may have fitness costs.