Long-Term Effect of Tail Loss on Home-Range Size and Access to Females in Male Lizards (Psammodromus algirus)

Radio-telemetry was used to investigate the home range and den characteristics of the brush-tailed rabbit-rat (Conilurus penicillatus) from three sites in the monsoonal tropics of the Northern Territory, Australia. Radio-tracking was conducted in a series of discontinuous 4–17-day sessions, over a 2-year period. The home ranges of 61 C. penicillatus were estimated using the minimum convex polygon (MCP) and fixed kernel (K95% and K50%) methods. There were no significant differences in home-range size among the three sites or between wet and dry seasons, which suggests that vegetation structure, floristics and season play relatively little role in movements of C. penicillatus. The mean home-range size was 0.79 ± 0.09 ha (MCP estimate) to 0.97 ± 0.12 ha (K95% estimate). The home ranges of males were larger than those of females (mean MCP estimates of 1.07 ± 0.15 and 0.45 ± 0.06 ha respectively). C. penicillatus denned primarily in fallen logs and in hollows of eucalypts and bloodwoods (Corymbia spp.). Rough-barked trees appeared to be preferred. The diameter at breast height (DBH) of den trees varied significantly between the three sites, being greatest at site C1 (34.5 ± 2.4 cm) and least at site C2 (26.1 ± 1.0 cm). Den trees had larger DBH than randomly selected trees at each site. The diameter at the mid-point (DMP) of both den and randomly selected logs were not significantly different between sites. Many individuals used more than one den site per tracking session. The small home ranges of C. penicillatus and its reliance on hollows in trees and logs suggest that this species is very vulnerable to local extinction following long-term annual and destructive fire regimes and land clearing, even in comparatively small patches.

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Home-range ecology, aggressive behaviour, and survival in juvenile lizards, Psammodromus algirus

Canadian Journal of Zoology ◽

10.1139/z00-083 ◽

2000 ◽

Vol 78 (9) ◽

pp. 1681-1685 ◽

Cited By ~ 17

Author(s):

Emilio Civantos

Keyword(s):

Home Range ◽

Home Range Size ◽

Range Size ◽

Home Ranges ◽

Vegetative Cover ◽

Agonistic Interactions ◽

Probability Of Survival ◽

Dominant Animal ◽

Psammodromus Algirus

Individual animals are assumed to gain possession of areas where they win fights or chases, while those that lose agonistic interactions leave areas where they were defeated. Thus, the more dominant animal secures the territory, often excluding subordinates from optimal habitat. This assumption forms the basis for concluding that the degree of aggressiveness or relative dominance of an individual may be important in determining the size or quality of a territory that it can secure. I examined in the field the relationships between home-range size, quality of home range, and degree of aggressiveness and their effects on survivorship in juvenile male lizards (Psammodromus algirus). The degree of aggressiveness was determined using tethered intruders presented to resident individuals in the field. The more aggressive individuals had larger home ranges than the less aggressive ones. Furthermore, home-range size and vegetative cover in the home range also influenced the probability of survival: survivors had larger home ranges, with a greater amount of vegetative cover, than nonsurvivors.

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