Publication Date


Document Type


First Advisor

King, Richard B.

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Biological Sciences


Garter snakes--Behavior; Garter snakes--Morphology; Testosterone--Physiological effect; Sex differentiation--Endocrine aspects


51 to 54 garter snake neonates from 7 families were tested to examine the effects of sex, family and testosterone on behavior and morphology. Animals were tested on five behavioral measures before testosterone implantation, after implantation, and after implant removal and hibernation. Mass and snout-vent length were measured shortly after birth, mass was measured during implantation, and mass, snout-vent length, head length, and head width were measured after implant removal and hibernation. All simple litter and time effects (except with time for antipredator behavior) were significant for the behavioral measures at or beyond the .05 level. The only other significant effect was the litter-by-time effect for antipredator behaviors. Among the morphological variables, litter effects were significant at or beyond the .05 level for mass and shout vent length. Sex differences and sex-bytreatment differences were significant for head length. This research arose out of an attempt to examine the organizational and activational effects of hormones on behavior. While no significant testosterone effects were found, a strong family (genetic) difference was found for the behavioral variables. In the morphological analyses, sex and sex-by-treatment differences were seen for head length. This was in agreement with earlier research. Strong family (genetic) differences were also found for morphological characteristics.


Includes bibliographical references (pages [73]-77)


vii, 77, [11] pages




Northern Illinois University

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