Population structure, territoriality, and social behaviour of three species of iguanid lizards.

The ecology of three lizard species was investigated in the Colorado National Monument, Fruita, Colorado. Sceloporus graciosus was most abundant followed by S. undulatus then Urosaurus ornatus. In all three species, (1) minimum annual survivorship was high despite a very cold winter period, (2) sex ratios were equal, (3) snout-vent length and weight were highly correlated, (4) some males were polygynous, and (5) male territories overlapped female home ranges. Male territories were not contiguous or significantly larger than female home ranges in only U. ornatus, and there was sexual size dimorphism in only S. undulatus. Juveniles of Sceloporus spp. could be distinguished on the basis of size alone, and they grew significantly faster than adults. In an adult S. graciosus females-removal experiment, neither treatment nor control conspecific males abandoned their territories. In a laboratory enclosure nine adult U. ornatus were monitored for information on territory displays and oviposition behaviour of females. Males were significantly more active than females, and they established a despotic hierarchy. Body mass was associated with male social status and there was a dominance shift. Escalated contests among males were infrequent relative to ritualized displays, and females were most active during the week prior to each oviposition. (Abstract shortened by UMI.)Dept. of Biological Sciences. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1990 .D485. Source: Masters Abstracts International, Volume: 30-03, page: 0629. Chairman: R. T. M\u27Closkey. Thesis (M.Sc.)--University of Windsor (Canada), 1989