Aspects of the Life History and Ecology of the Olympic Salamander, Rhyacotriton olympicus (Gaige)

Abstract

Life history attributes of two populations of Rhyacotriton olympicus were studied in western Oregon. A population in the Coast Range had (1) smaller eggs; (2) smaller metamorphic size; (3) smaller size at maturity; (4) smaller mean adult size; (5) smaller maximum size, and (6) higher fecundity, compared to a population in the Columbia River Gorge. Also, the population in the Coast Range is thought to have smaller hatchlings and lower age at maturity. Females are larger in both populations. Spermatophores were found in females in all months except August, September, December and January, indicating an ex- tended courtship season. Similarly, oviposition may occur at almost any time,, although there is a peak of courtship and egg-laying activity in May in both populations. Data on growth, density and movement of marked larvae are given for the population in the Columbia River Gorge. Females reproduce annually and apparently do not attend the embryos. In many respects, the reproductive mode of R. olympicus is more like that of hemidactyliine plethodontids than other ambys- tomatids.