Tiger salamander pitfall trap equipment12/14/2023 The number of amphibians we see in a puddle will translate differently into real numbers than the numbers we see in a large pond. “We also take the size of the pond into consideration when we do estimates. To get a sense of what the population density is like for an area, you have to look at several ponds to really get a sense of the variation,” Fork explains. You can have a lot of a species in one pond, and hardly any in another. ![]() “It’s important to sample a number of bodies of water before estimating the population size. Monitoring of amphibian species is performed by looking at individuals caught by nets and estimating total numbers based on numbers caught. Some of its toes are relatively long for its size (hence its name) and skinnier,” says Fork. The Santa Cruz Long-toed Salamander is also black, but is smaller (4-6 inches) has an orange dorsal stripe with white side speckling. “The California Tiger Salamander is larger, growing to 7-8 inches long and is black with yellow blotches. While both California Tiger Salamander and the Santa Cruz Long-toed Salamander are both black with lighter markings, they can be differentiated visually. To a casual observer, the two endangered salamanders Fork looks for appear somewhat similar but have key differences. While both larvae have tails, only salamanders keep their tails into maturity. Salamander larvae have external gills, but tadpoles have internal gills with a covering. Whereas frog young are called tadpoles (or larvae), salamander young are called larvae, but not tadpoles. At the larval stage, frog and salamander larvae are similar but have some differences. They are all considered threatened or endangered.” Seine nets are also be used to cordon off frogs and salamanders so they can be counted. “We especially keep an eye out for California Red-legged Frog larvae, California Tiger Salamander larvae and Santa Cruz Long-toed Salamander larvae. “We do dip net surveys in 25 – 30 bodies of water to catch frog and salamander larvae to get a sense of the population densities for various species,” she says. “Much of the monitoring we do helps to generate baseline data,” says Fork.Įvery spring, Fork and volunteers pull on their waders and go waist deep in the water for science. They look at density data along five transects. In addition to shorebirds, Fork and volunteers revisit the Elkhorn Slough mudflats once a year to gather data on clams, shrimp and worms. Staff uses various optics (including Vortex, Eagle Optics, Nikon), and volunteers have additional favorite optics (Swarovski, Leica, etc.).” “For birding, people bring their own equipment, binoculars and spotting scopes. “We do shorebird monitoring here quarterly, with lots of volunteer assistance,” she notes. ![]() It’s called the California Red-legged Frog, and it’s actually becoming rarer over the years,” she says.įork has been a research biologist at Elkhorn Slough NERR since 2001. ![]() If you’ve ever heard of the Jumping Frog of Calaveras County, in the Mark Twain story, that species of frog is at Elkhorn Slough. There is also a threatened frog species we monitor for here too. “Salamanders are an important part of our work, with some rare species making their homes here. While many National Estuarine Research Reserves (NERRs) monitor for shorebird, fish and crab populations, Susanne Fork, research biologist at Elkhorn Slough NERR in California, delights in the small and the slippery – amphibians, insects, clams, and worms.
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