Turtle imprinting

Burghardt, G. M. and Hess, E. H. (1966). Food imprinting in the snapping turtle, Chelydra serpentina. Science 151,108-109. 

Grassman, M. and Owens, D. (1987). Chemosensory imprinting in juvenile green sea turtles, Chelonia mydas. Animal Behaviour 35,929-931. 

New evidence indicates that chemical imprinting in sea turtles will have to be even more phenomenal than previously imagined if it indeed occurs. Studies on predicted age of sexual maturity suggest 15-35 or more years for earliest maturation in green and loggerhead sea turtles (Balazs, 1980 ... 

Table 1. Aquatic Turtle Behavior as It Relates to Odor Imprinting. ... 

These turtles were borrowed from the international conservation program which is using "artificial imprinting" to attempt to establish a new nesting beach for this endangered species. Our four-compartment arena was used once again, and the animals were individually evaluated for number of entries, total time spent and time spent per entry into compartments treated with 1) Padre Island seawater used to wash Padre Island sand ... 

Groups of hatchlings were "artificially imprinted" to morpholine and phenylethanol in a protocol similar to that of experiment 2 (Table 1). Treatment groups were exposed to one of the two chemicals at 5 x 10 5molar concentrations either in the nest alone, in both the nest and tank water or in the tank water alone (total of six treatments). Using the four choice chamber once again, the turtles were evaluated two months after exposure to the... 

Our interpretation of this experiment is that if turtles receive a relatively long exposure to an olfactory cue (e.g., both in the nest and tank water), they can learn (imprint to ) that cue and at a later time show a characteristic response to that cue. In this case, the response is a specific orientation pattern to the chemical used. 

While this last experiment appears to satisfy the classical definition of imprinting (Lorenz, 1937), we have no way of knowing if these juvenile turtles could remember specific cues in two to three or more decades when, as adults, they would normally begin their reproductive migration in search of a breeding beach. 

These experiments do not prove that chemosensory imprinting to the natal beach occurs in sea turtles. We do believe, however, that this research has added to the credibility of the olfactory (chemsensory) imprinting hypothesis as originally proposed by Carr (1967). 

Grassman, M. A., 1984, The Chemosensory Behavior of Juvenile Sea Turtles Implication for Chemical Imprinting, Ph.D. dissertation, Texas A M University. 

Grassman, M. A., and Owens, D. W., in press. An attempt at an experimental evaluation of imprinting in the Kemp s ridley sea turtle (Lepidochelys kempl), in Proceedings of the First International Symposium on Kemp s Ridley Sea Turtle Biology, Conservation and Management, ... 

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