Indicators of environmental health
San Benito County is home to several amphibian species.
Biologists monitor amphibians closely because they are key
indicators of the overall health of a place
– canaries in the coalmine.
Indicators of environmental health
San Benito County is home to several amphibian species.
Biologists monitor amphibians closely because they are key indicators of the overall health of a place – canaries in the coalmine.
The reason is bound up in the way amphibians are built. All amphibians are, well, amphibious, most spending part of their lives as aquatic creatures. They lay eggs in water, and some spend nearly all their lives in water.
Others, like the California tiger salamander, roam far from their natal pools.
Another trait amphibians share is a thin, very porous skin. It’s what gives them that cool, clammy feel in the hand. That skin does not offer the barrier to outside toxins that our own much tougher skin does. Before handling amphibians, it’s important to ensure that one’s hands are clean and free of soap residue, because even that can have fatal consequences.
According to the staff at Pinnacles National Monument, the following species can be found locally.
Ensatina
The colorful, lungless Ensatina genus is divided into seven subspecies that vary markedly in appearance. A profile of the salamander published by Santa Rosa Junior College indicates that this species – rare in San Benito County – offers biologists the opportunity to study Darwinian speciation in progress.
Gabilan slender salamander
Slender salamanders are small, dark creatures relatively common to this area. They can be found in moist spots – say, under planks and large stones – even within the confines of Hollister and San Juan. Not more than a few inches long, they have legs that have shrunk over time to mere vestiges. Rather than walking, they move in a serpentine squiggle like snakes. When it’s cold or dry, these easy-to-miss animals burrow underground.
Arboreal salamander
As its name suggests, this large, brown salamander spends its life in trees and shrubs, ranging up to 50 feet high. It may hide in tree hollows or behind bark. It is unusual in that it does not need to return to water to lay eggs and has no larval stage. Young resemble smaller versions of adults.
It is adapted to its Tarzan lifestyle with a prehensile tail that can curl around twigs. Further, the arboreal salamander has a robust jaw capable of inflicting a painful bite. Its diet consists of a variety of insects and even slender salamanders, according to the San Diego Natural History Museum.
It, too, is lungless, absorbing oxygen directly through its skin.
Western spadefoot toad
A nocturnal resident of grasslands and chaparral, this toad with golden eyes has relatively smooth skin, for a toad. Its skin secrets a liquid that smells like peanut butter, should you get up close and personal with this pudgy amphibian.
Western toad
A large, warty looking toad, it is distributed widely. This toad is mostly terrestrial and may be found in backyard gardens. Females lay eggs in water. The gelatinous eggs appear in long strings, and a typical clutch contains 12,000. Once relatively abundant, its numbers appear to be declining. The toad is particularly sensitive to increased ultraviolet radiation.
Pacific treefrog
Small, smooth-skinned frogs with long, narrow heads, these small frogs are among the loudest amphibians, and can fill spring nights with a persistent chorus. They range from shades of brown to bright green. Its sticky toe pads allow it to cling even to glass and it is a capable jumper.
California red-legged frog
This large frog is one of biologists’ marquis species. It was once so common that market hunters brought them to San Francisco restaurants by the thousands, where their legs were served to diners. The best place to see them locally is at the Bear Gulch Reservoir at Pinnacles, where park staff eliminated non-native predators and restored the native frog population.
This frog is officially classified as threatened, probably due to loss of habitat and pollution. It can be identified by the bright red slash along the inside of its hindlegs.
Bullfrog
This large, aggressive predator with teeth in the roof of its mouth was introduced to California as a food source. It’s distinctive booming call cannot be missed. These large frogs are indiscriminate eaters, taking native amphibians, fish and even small birds and mammals. Where bullfrogs are found, red-legged frogs have usually been consumed as prey.
