Rain wakes up tree frogs, who blast SLO County with ‘kreeking’

The booming chorus of thousands of high-pitched “kreek-eecks” from a gathering of small but tenacious Pacific tree frogs has filled the entire Avila Valley over the last few nights.

These little male frogs with their relatively large heads, eyes and eardrums sit near the bank of San Luis Obispo Creek and belt out a remarkably loud sound.

These frogs shut their nostrils and mouths and squeeze air from their lungs into their vocal pouches. These sacs stretch like balloons and serve as a resonating chamber, allowing these small frogs to produce sound that can exceed 90 decibels.

Even at the PG&E Energy Education Center, on Ontario Road across Highway 101 from San Luis Obispo Creek in the Avila Valley, the frog sounds can be heard over the lonesome sound of spinning tires on passing semi-trucks.

The Pacific tree frog, also known as the Pacific chorus frogs, live over an enormous area that stretches along the Pacific Coast from British Columbia south to Baja California. They seem to especially like the mild climate of San Luis Obispo County.

Despite their name, this frog is essentially a ground-dweller, living near bodies of water. Last weekend’s rains, combined with overnight temperatures above 50 degrees, have awakened these frogs as they head into the peak of their mating season between February and March.

The males generally sit near the edge of any type of creek, puddle or ditch and use different types of vocalizations to communicate with other frogs.

The two-part kreek-eeck sound with the last syllable rising in inflection is the call for females, while a prolonged one-note sound warns other males to keep away. They’ve also been known to use the one-note sound to signal a change in atmospheric pressure and the onset of rain.

Because these frogs are also found in the Los Angeles area, the film industry has made the distinctive call of the Pacific tree frog the standard frog call heard in most movies. The frogs in coastal San Luis Obispo County may be active all year.

In hotter or colder climates, these frogs hibernate in moist areas under rocks, fallen trees or dense vegetation to avoid temperature extremes. Like an arctic fox changing its colors through the year, these frogs can change their color from brown to green from one season to another.

This camouflage is believed to be related to the temperature and the amount of moisture in the air.

Depending on air temperature, it takes about a week for the eggs to form into tadpoles.

After that, the tadpoles begin to feed on whatever is available in the water, like green algae. It takes about a year for the tadpole to become a member of the breeding chorus.

This week’s forecast

This morning’s temperatures will range from the mid-20s in the North County and the mid-30s in the coastal valleys. Fog in the San Joaquin Valley will remain overcast in the far southern San Joaquin Valley around Bakersfield.

A cold front will sweep through Northern California tonight and will reach the Central Coast on Monday. This cold front will not produce any rain over the Central Coast.

However, it will give increasing clouds with areas of night and morning fog and warmer overnight low temperatures throughout San Luis Obispo County.

The remainder of the week will feature partly cloudy skies and slightly above normal temperatures with some patchy late night/early morning ground fog; no precipitation is forecast through next Sunday.

Beyond that, dry weather with mild temperatures look likely through the first week of February with increasing chances for rain around the 10th.

Surf and sea report

Today’s 3- to 5-foot northwesterly (295-degree deep-water) swell (with an 11- to 13-second period) will remain at this height and period through Monday morning.

Increasing northwesterly winds will generate a 3- to 5-foot northwesterly (315-degree deep-water) sea/swell (with a 5- to 15-second period) Monday afternoon into Tuesday.

A 4- to 6-foot northwesterly (295-degree deep-water) swell (with a 14- to 22-second period) will arrive along the coast Tuesday night, increasing to 6 to 8 feet (with a 12- to 20-second period) Wednesday.

This northwesterly (295-degree deep-water) swell will remain at a 6- to 8-foot level, but its period will decrease to 11 to 16 seconds on Thursday into Friday.

The long-range models and charts are still not indicating any high-energy swell events along with Pecho Coast for an extended period of time. Seawater temperatures will range between 54 and 56 degrees through Friday.

Conservation tip

An interesting blog that provides an in-depth look at the intersection of energy and the environment can be viewed at www.pge currents.com/next100/.

NEXT100 is written and edited by Jonathan Marshall and it focuses on trends in green technology policy and the Earth’s climate that will most impact the energy industry and PG&E customers over the next 100 years —PG&E’s second century in operation.

John Lindsey is a media relations representative for Pacific Gas and Electric Company and longtime local weather expert. If you have a question, email him at pgeweather@pge.com.