Tailed Frogs: Distribution, Ecology, and Association with Timber Harvest inNortheastern Oregon

摘要

The study was designed to investigate the distribution, abundance, life history,and effect of timber harvest on tailed frogs. In 1992, 80 streams in northeastern Oregon were surveyed for tailed frogs. More intensive surveys (diurnal searches for larvae and nocturnal searches for adults) were conducted in 30 streams in 1993. Tailed frogs were found in streams in four counties (Union, Umatilla, Wallowa, and Baker Counties) in northeastern Oregon. Their presence in three of these counties was previously unknown. Tailed frog adults and larvae were present in streams all summer. It appeared that three or more age classes of larvae were present in most streams, thereby suggesting that larvae are in the streams at least 3 years before they transform into frogs. Transforming larvae were found in streams in July, August, and September; none was found in October. There were no significant differences in numbers of larvae or adults in streams with a low, moderate, or heavy amount of timber harvest; however, there was a general downward trend in the abundance of tailed frogs as the amount of timber harvest increased.