Date of Award


Degree Type


Degree Name

Doctor of Philosophy



Major Professor

Gordon M. Burghardt

Committee Members

H. Charles Gordon, Cheryl B. Levies, Julian M. Wallace, William Alphord


Scientific and popular accounts of cockfighting are reviewed, and cultural and psychological aspects of the sport are examined. Information is presented on breeding and husbandry of gamecocks, fight preparation, rules and types of fights, gambling practices, and legal aspects of cockfighting. The scientific literature on the agonistic behavior of gamecocks, descriptive studies of fighting in chickens and the factors which determine fight outcome.

In Chapter III data recorded at actual cockfights are presented. This includes information on fighting behaviors, fight length, number of "pittings" (rounds) per fight, pitting length, the effect of weight on outcome, and survivorship. Of particular interest are observations of immobility responses similar to manually induced tonic immobility (TI) or "animal hypnosis." This response occurred in 33 of 86 fights and in 227 of 1,528 pittings. The response was relatively more frequent in longer fights suggesting that fatigue and exhaustion may facilitate the response. It was also found that mobile animals are attacked with greater frequency than immobile animals suggesting a possible function for the behavior. A possible evolutionary relationship between fatigue, TI and submissive postures is discussed.

In the second part of the dissertation are presented the results of three experiments designed to examine strain difference between gamecock chicks and chicks of two commercial strains, White Leghorns (WL) and Rhode Island Reds (RIR), in regard to TI and open field behavior. Previous research has shown that WLs show greater TI duration than RIRs and are more "emotional" in terms of open field behaviors. It was hypothesized that the GCs would show greater TI than the other strains because of greater selection pressure for the response both during cockfights and in predator-prey encounters. In Chapter IV the literature pertaining to several aspects of TI is reviewed; theoretical issues, methodological difficulties and problems associated with operationally defining the response, and genetic influences.

Experiment 1 was designed to assess strain differences in duration and susceptibility to TI. The subjects were two-week old WLs, RIRs, and GCs which were housed and tested in single strain groups using a 25 min ceiling TI duration. The results did not support the hypothesis that the GCs would show greater TI duration and susceptibility. Although there was a significant difference between WLs and RIRs and between the GCs and RIRs in regard to duration, there was not a significant difference between the WLs and GCs. A significant difference was found between the strains in the number of subjects becoming immobile on the first induction trail with 53% of the RIRs, 83% of the WLs, and 87% of the GCs showing the response on the first trail.

Experiment 2 was a replication of Experiment 1 using a longer ceiling duration (120 min) and with the subjects house in mixed strain groups. As in the first experiment there was a significant difference between the RIRs and the WLs in TI duration. In this experiments, however, the GCs shifted and were significantly different from the WLs but not the RIRs. Data on susceptibility to induction procedures were consistent with Experiment 1 with 30% of the RIRs, 76% of the WLs, and 70% of the GCs becoming immobile on the first trail.

Experiment 3 examined strain differences between the three strains in open field behavior using five and six day old chicks. Five dimensions of open field behavior were recorded: latency to move from center square, ambulation, latency to peep, number of peeps during the trial, and number of defecations. On all of the dimensions there were significant differences between WLs and RIRs. The game chicks were found to differ from the RIRs in ambulation and number of defecations, and they differed from the WLs in latency to peep and number of peeps.

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