Publication Date


Advisor(s) - Committee Chair

Blaine Ferrell, Rudolph Prins, Joe Winstead

Degree Program

Department of Biology

Degree Type

Master of Science


A contingency analysis of the sequence of actions associated with agonistic behavior of resident and introduced male Sceloporus undulatus nya irthirus was carried out to determine the degree of stereotypy. During the time period April to June 1984 and 1985, caged pairs of adult male and juvenile female lizards were filmed on three occasions in order to gather data on resident males not involved in aggressive interactions. During the same threemonth time period, a different nonresident male was introduced singly into a given resident's cage on three occasions and the interactions filmed. The films were analyzed to determine which actions were agonistic, the sequence of actions and the transition frequencies from one action to another. The sequence of actions was determined to be probabilistic, that is, the occurrence of one action influenced the probability that a specific action would follow. The most probable behavioral sequence for resident males during male-male interactions was head turn-crawl-jaw snap-lateral compression-bobbing-attack. The latter three actions were unique to agonistic encounters. The introduced males expressed a similar behavioral sequence except that they very rarely attacked. The behavioral sequence of resident females during male-male interactions consisted of head turn-crawl-jaw snap-bobbing. Bobbing generally preceded jaw snapping in females when such male-male interactions were not taking place. The probabilistic nature of the display action pattern during agonistic behavior is similar to that observed in other iguanid lizards studied. Three levels of arousal were evident in resident males during aggressive interactions. These were 1) heightened awareness, 2) display and 3) attack. Again, this observation is consistent with those in studies carried out in other iguanid lizards.


Animal Sciences | Biology | Life Sciences | Other Animal Sciences