ABSTRACT Experimental Analysis of Alternative Male Strategies PI: SINERVO, Barry IBN 96-31757 Three color polymorphism s of males are correlated with distinct behavioral strategies in the side-blotched lizard, Uta stansburiana: (1) orange-throated males are very aggressive and defend large territories with many females, (2) blue-throated males tend to be monogamous and guard their mates, but defend small territories, and (3) yellow- throated males do not defend territories, but are sneakers and mimic the behaviors of females if challenged by other males. Long-term field studies indicate that the three male types are cycling in frequency within the population. Orange is replaced by yellow, yellow males are, in turn, vulnerable to blue mate-guarding males, and blue males are, in turn, vulnerable to ultra-dominant orange-throated males. It is predicted that each morph has a fitness advantage when it occurs at a very low frequency. Because throat color is heritable, the initial morph frequency will be manipulated in small isolated subpopulations. When offspring mature, DNA paternity analysis will be used to determine the reproductive success of each male offspring in the three experimental frequency manipulations. In a final experiment, blood testosterone concentrations will be manipulated to determine if the high testosterone levels that have been observed in orange males is also responsible for both their success against blue males, and their susceptibility to the yellow male strategy.
