Season of the Toad

This tiny toad, barely two centimeters long, has just emerged from the water and is beginning to adapt to life on land after spending its first month in water as a tadpole. Young toads like this one are vulnerable to predators like ravens. They have to blend in and move fast to survive. Photos by Suzanne Guldimann

Anaxyrus borea sounds more like the name of a dragon in a fantasy story than a real-world amphibian, but in its small way, the Western toad is as remarkable as any mythological creature.

The Woolsey Fire and subsequent flooding has created a setback for several native amphibians, but the Western toad wasn’t impacted by the loss of the deep pools necessary for California newts and the endangered red-legged frog to successfully breed. In fact, shallow pools exactly suit the toad, and the absence of predators in the aftermath of the fire has given toad tadpoles and juveniles a better chance at survival. 

A single female Western toad can lay up to 17,000 eggs at a time. The eggs, attached to sticky strings that anchor them to rocks or vegetation in the stream, hatch into tadpoles within 10 days. 

About a month later, the tadpoles begin to enter metamorphosis, growing legs and lungs, and eventually emerging as juvenile toads. The young toads congregate on the edge of their stream or pond before dispersing. As adults, they will spend most of their lives on land, only returning to the water to breed. 

Western toads can live for as long as a decade, and grow to be more than five inches long, making them one of the Santa Monica Mountains’ largest amphibians. Most Western toads have a distinctive white line down their backs. They range in color from tan to greenish-brown, and often have colorful reddish patches. Like all toads, they have a round bump on each side of their head called a parotoid gland that secretes a milky fluid containing potent neurotoxins.

Not many predators will eat an adult toad, but tadpoles are a popular menu item for a large number of predators, including egrets, raccoons, and even other amphibians. Usually, only a few of those 17,000 eggs survive to adulthood. This year, the odds have shifted in favor of the toads, and the number of young toads is much higher than usual.

“We’re finding toads in all sorts of places,” National Park Service ecologist Katy Delaney told the Messenger Mountain News, confirming that the large number of toads sighted recently is unusual.

“We’ve seen toads in three or four streams where we’ve never seen them before,” Delaney said. “They like shallow water, and many streams [in the Woolsey Fire burn zone] have been filled with a lot of sediment. Instead of pools of water we are seeing what’s called ‘riffle,’ shallow, flowing water.”

Delaney, who is the lead ecologist in a program to re-introduce the locally extinct red-legged frog to the Santa Monica Mountains, is hoping that subsequent rainy seasons will wash out the sediment and restore the pools needed by the red-legged frogs and some of the other displaced amphibians.

Adult toads have a powerful chemical weapon, a toxic secretion known as “bufotoxin” that discourages predators from eating them. A toad that survives to adulthood may be safe from most predators but still faces challenges. This species is long-lived but is vulnerable to vehicle strikes and is increasingly at risk from climate change.

In the meantime, it’s the season of the toad. Look for baby toads at the edge of creeks and ponds. Listen for the adult toad’s bird-like “peeping” from the brush, where toads spend their nights hunting insects. Western toads are rarely found in urban environments, but this squat amphibian is a welcome garden resident in Topanga, because its diet includes pests like grasshoppers and beetles.

Western toads occur throughout the western U.S., from Baja, California to coastal southern Alaska, and as far east as the Rockies. Like almost all amphibians, this species is increasingly impacted by climate change and habitat loss and a number of populations are near threatened, including the toads of the Santa Monica Mountains National Recreation Area, a park species of concern. 

Slow-moving and mostly nocturnal, toads are frequent victims of vehicle strikes, especially during their breeding season when they cross roads in search of mates. They are also impacted by development, water contaminants, and invasive non-native species like crawfish.

Local residents and visitors can help protect toads and all native amphibians by staying out of the water in local creeks, and making sure to cross on rocks or bridges in locations where hiking trails cross a creek.

“People love to hike up streams, but there’s a negative impact,” Delaney said. “It makes it harder for species like frogs and toads. It’s another stress on the ecosystem. If you love amphibians, stay out of their habitat.”

Making sure garden runoff, fertilizer, and pet waste stay out of creeks and streams also helps safeguard amphibians, and slowing down on the road at night may save more than a passing toad.

 

Suzanne Guldimann
Suzanne Guldimann

Suzanne Guldimann is an author, artist, and musician who lives in Malibu and loves the Santa Monica Mountains. She has worked as a journalist reporting on local news and issues for more than a decade, and is the author of nine books of music for the harp. Suzanne's newest book, "Life in Malibu", explores local history and nature. She can be reached at suzanne@messengermountainnews.com

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