California Red-legged Frogs Blog Posts

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California Red-legged Frog Numbers on the Rise at Muir Beach

05/31/2017

A close-up look at a California red-legged frog egg mass.
California red-legged frog eggs. Photo by Paul G. Johnson.

Every winter, California red-legged frogs (Rana draytonii) egg masses are monitored in ponds and streams at Muir Beach and other sites in the Golden Gate National Recreation Area. Recent restoration efforts at Muir Beach, complimented by the relocation of red-legged frog egg masses to the site, seem to be paying off for this threatened species. The past two years have seen the highest egg mass numbers since monitoring began at this site in 2002.

Increased numbers of egg masses have also been seen at monitoring sites in Tennessee Valley, Rodeo Valley, and Rancho Corral de Tierra this season; however, egg mass production has declined at Mori Point since the winter of 2013. Contact Darren Fong with questions.




California Red-legged Frogs Thrive in Redwood Creek Watershed

05/28/2015

Graph of egg masses observed during surveys of the Redwood Creek watershed.

The 2015 breeding season for the federally threatened California red-legged frog has concluded earlier this spring. Since 2002, surveys have been conducted in the Golden Gate National Recreation Area every couple of weeks starting in December and ending in early April. The surveys focus on slow, freshwater habitats like ponds and creek backwaters where egg masses are located and counted. The egg masses are the size of grapefruits and can usually be found attached to vegetation in the water. This year, breeding was documented at six sites in San Mateo County and six sites in Marin County, including the first ever record for a site in Tennessee Valley. Of particular interest is the Redwood Creek watershed where several ponds and backwater habitats were created after breeding was last documented in 2004. In 2010-2011, red-legged frog egg masses were introduced into a created pond in lower Redwood Creek. Subsequent monitoring has shown a dramatic increase in the breeding population of red-legged frogs in this watershed. Some of the increased production has come from colonization of new sites at Muir Beach a half-mile from the initial introduction site. For further information, please contact Darren Fong.




California Red-legged Frog Surveys in San Mateo County

09/30/2014

Close-up of a California red-legged frog egg mass. Photo by Paul G. Johnson.

Both Milagra Ridge and Mori Point, portions of the Golden Gate National Recreation Area in San Mateo County, contain restored wetland habitats that support federally threatened California red-legged frogs. The Golden Gate National Parks Conservancy’s Park Stewardship Program monitors California red-legged frog egg masses at ponds across both sites to confirm frog presence or absence and to understand trends in the winter-breeding frog population. Breeding and egg mass production typically begin following the first heavy rains of the season, which usually come in December. Last year, however, the rains did not begin until February. As a result, egg mass surveys were limited to a narrow window from February to April. The number of egg masses at all four ponds monitored at Mori Point were lower than the previous year, but at the Milagra Ridge pond, the number of egg masses increased. Since only four years of surveys are available from some locations, it is too soon to examine greater trends and no correlation can be confirmed between total rainfall and the number of egg masses. It is also likely that a number of other factors and conditions at individual ponds are also playing important roles in influencing California red-legged frog breeding success. More years of monitoring data will continue to improve our understanding, but for now the good news is that in spite of very dry conditions, California red-legged frogs are continuing to breed at all monitored locations. Check out the full report on 2014 California red-legged frog surveys at Milagra Ridge and Mori Point, or contact Ruby Kwan with any questions.




New California State Amphibian

07/31/2014

California red-legged frog. Photo by Paul G. Johnson.

The federally threatened California red-legged frog has been named California's official state amphibian. Also a state species of special concern, the frog has been extirpated from a lot of its historic range but is still relatively common in the San Francisco Bay Area. It can be found around creeks and wetlands in Golden Gate National Recreation Area, Point Reyes National Seashore and Pinnacles National Park. Learn more about the naming of California's latest official symbol from the California Department of Fish and Wildlife.