| Popis: |
Optimizing conservation efforts requires distinguishing between rare and potentially endangered species (few extant individuals, functionally rare) and species that are difficult to find (operationally rare). Certain suites of life-history parameters such as slow growth, late maturity, low fecundity, and long interbreeding intervals are thought to be associated with functional rarity and with intrinsic vulnerability to population declines. We estimated life-history parameters by using capture-recapture data of one such elusive species, the Sharp-tailed Snake (Contia tenuis), from 1997 to 2005 in northern portions of its range in British Columbia, Canada. Body size ranged from 84 mm (smallest juvenile) to 323 mm (largest female). Mean snout–vent lengths were 212 ± 14 mm (mean ± SD) for adult males and 251 ± 28 mm for females. They were slow growing (adult growth rate, 4.3 ± 3.8 mm/yr), had extended time-to-sexual maturity (5–6 yr), and had small clutch size (3.6 ± 1.1 eggs). Estimated adult surviv... |
