Even though it has the word ‘tree’ in its name, the Sierran Tree Frog is mostly found close to the ground, in bushes and grass. It has large toe pads that allow it to walk on vertical surfaces better than Spider-Man. The toe pads are also useful for clinging to sticks and twigs.
To avoid being eaten, the Sierran Tree Frog is fast! It can jump long distances and swim quickly to hide in vegetation. It also remains perfectly still and changes color to stay camouflaged. Sierran Tree Frogs can change from green and gray to brown.
Worms, small invertebrates, and flying insects are the frog’s dietary staples. Tadpoles feed on algae, bacteria and organic debris. Their feeding activities help keep streams and waterways clear of slippery plant material.
The Sierran Tree Frog is more often heard than it is seen. Males call to advertise availability and attract mates. Breeding and egg-laying occur from November through July. During this time, males establish a territory that they defend with encounter calls, butting, or wrestling with rivals.
Global Amphibian Issues
Scientists say that we are living in the Anthropocene epoch, a time when human activity is the dominant influence on climate and the environment. Unfortunately, the consequences of this are that many habitats and species will disappear.
Frogs and newts are indicator species because they have thin skin that easily absorbs pollutants. Since they live both in water and on land, they absorb toxins from both environments. Like the miners who used canaries to warn when toxic gas was present, amphibian health determines the quality of the environment.
There are a number of factors that affect amphibian populations. Not unique to Nevada County, these conditions are happening globally.
Contributing Factors to Amphibian Decline:
Loss of habitat (housing development)
“We’re running out of places where frogs are healthy,” Amphibian Study Volunteer
“It doesn’t matter how many frogs we save if there is no place to put them back in the wild,” Edgardo Griffith, El Valle Amphibian Conservation Center
Chytridiomycosis (Batrachochytrium dendrobatidis – Bd) skin fungus (global epidemic)
Pesticide runoff & flushed prescription medications
California Pesticide Use:
California agriculture is the number one consumer of pesticides in the United States.
The state produces half of the US agricultural produce.
- 99 percent of artichokes
- 99 percent of walnuts
- 97 percent of kiwis
- 95 percent of garlic
- 89 percent of cauliflower
- 85% of the lettuce
- 71 percent of spinach, and
- 69 percent of carrots
Contaminated agricultural water runoff affects the entire ecosystem.
“Atrazine (an herbicide) is the most common contaminant in our drinking water. It causes male frogs to turn into females.” – Tyrone Hayes, UC Berkeley Biologist
“Bullfrogs pose several threats to the native amphibians of California, many of which are endangered. When bullfrogs—the largest frogs in North America—escape or are released into the wild, they have a tendency to eat other amphibians and any other wildlife that will fit in their mouths. Their size also allows them to outcompete native species for food. Even worse, a large portion of the bullfrogs imported into this country—62 percent according to one study—are infected with the deadly chytrid fungus (Batrachochytrium dendrobatidis), a lethal skin disease which has already been blamed for extinctions of about 100 amphibian species around the globe.” – Should California Ban American Bullfrogs? Scientific American Blog
How to Help
Be a Lorax (speak up) for Nevada County frogs, toads, and salamanders
- If you see a frog die-off (more than one dead in a single location) – DON’T TOUCH IT – but do report it
- Don’t move amphibians from one location to another
- If fishing, wash & dry gear before moving between spots
- Don’t pour anything down a storm drain that would damage amphibians
- Use environmentally friendly solutions for pest & disease management & weed control
- Dispose of prescription medications at a Prescription Drug Take-Back location
- Restore or create a pond
- Learn more about Amphibian Declines – educate friends & family
- Volunteer with survey and monitoring programs
- Volunteer with SYRL, become involved in dam re-licensing issues
- Work with Nevada City, Grass Valley, and the Nevada County Planning Commissions to preserve amphibian habitat
- Be active locally, state, and nationwide to Reduce Greenhouse Gas Emissions & Global Warming
- Donate to organizations that protect amphibians
- Become involved with pesticide regulations
Discovering Sierra Reptiles and Amphibians, Basey, H. E.
The Audubon Society Field Guide to North American Reptiles & Amphibians, Behler, J. L., King
AmphibianWeb – Overview of Chytridiomycosis
Chytrid in Nevada County – Sierra Streams Institute
Frogs Need Our Help – amphibianfoundation.org
Hazards of Atrazine herbicide – Clear Health Centers video
Indicator Species – ecology.com
Nevada County Resource Conservation District – Amphibians
Reproductive problems linked to atrazine – Tyrone Hayes, UC Berkeley Biologist
Wildherps.com– Sierran Tree Frog
Service Working to Combat Killer Chytrid in California Frog Populations – Sacramento Fish & Wildlife Office
State of Sierra Frogs (2008) PDF – Sierra Nevada Alliance
Wildherps.com– Sierran Tree Frog
What if there is no happy ending? – Scientific American, 2013
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