Saturday, March 28, 2015

Advanced Frog-Stalking


Day 166: "Practice makes perfect." I'm getting better at this. Of eight or nine froggies visible from a distance of fifteen feet, I only spooked two as I clambered over the boulders surrounding their pool in the hopes of getting a "field guide" photo showing the full morphology. My success solidified what I had suspected: these are Cascades Frogs, Rana cascadae, as evidenced by the yellow belly and distinct black spots.

The Cascades Frog ordinarily breeds from April to June. However, I observed a large mass of eggs in which the tadpoles were already clearly visible. According to the Washington Herp Atlas, breeding begins when water temperatures reach 46° F. This species breeds in still or slow-moving water. The larval period lasts two months. Adults may measure as much as three inches in length from snout to vent. Cascades Frogs can be found at altitudes of 2000' and higher, above the upper limit for the Red-Legged Frog. There have been no reports to indicate that this species is in decline, and from what I observed on this occasion, there are likely to be many more generations of Rana cascadae to come.

No comments:

Post a Comment