2014 California Red-legged Frog Survey, Mori Point and Milagra Ridge: Final Report

Kwan, Ruby

This report summarizes the results of the 2013/2014 seasonal surveys of California red-legged frog egg masses at known breeding areas. The goal of the egg mass survey is to determine the presence or absence of the red-legged frog at Mori Point and Milagra Ridge, and to assess trends in the abundance of winter-breeding red-legged frogs. Park Stewardship Program staff and interns conducted four egg mass surveys during the winter monitoring season on February 12, 25, March 14, and April 8. New egg masses were observed during all surveys except the last one. The peak in observations occurred on February 12, after the first heavy rains. The total number of egg masses observed this year increased at Milagra Ridge from 20 to 39, while there was a sharp decline (113 to 16) in egg masses observed a Mori Point. Egg masses were observed at all ponds at Mori Point except at the Middle Pond. At Milagra Ridge, 58% of the total egg masses observed were attached to floating vegetation close to the perimeter of the pond. It would be interesting to see if there is a correlation between the number of egg masses and the distance from the edge of the pond. As this was a particularly dry year and most of the ponds did not have water until February, breeding and oviposition which would normally begin in December was restricted to a narrow window. The dry conditions may also have impacted the frog physiologically and the stress caused by the environment may have made it less favorable for the frogs to mate, produce, and lay eggs. Fortunately, all ponds in both sites continue to serve as good breeding habitats as evidenced by the presence of egg masses in ponds found at Milagra and Mori Point. At Mori Point, the Southern and Wetland Ponds continue to be the more frequented pond while the Middle Pond is less frequented.