Petaluma Profile: Wetlands guide authors encourage appreciation of local treasure

Marian Parker has a suggestion for anyone walking through the Petaluma wetlands.

Stop, sit down on one of the memorial benches that line the trail at Shollenberger Park and turn off your phone.

“Shut your eyes and listen,” said Parker, a biologist who is intimately familiar with the wildlife of the Petaluma River watershed. “Hopefully, you can tune out the traffic noise. It will take 10 or 15 minutes, but you’ll start to hear the noise of nature.”

It may be the rasping of a mallard, the hiss or snort of a swan or the cheerful burbling of a marsh wren. Then open your eyes, look around, pull out your field glasses and try to spot what you are hearing. What is it? Is it a Great White Egret with pure white plumage or the slender, smaller, short-necked Snowy Egret? Is it a Dunlin Sandpiper or the petite Least Sandpiper?

Fortunately, you don’t have to be a serious birdwatcher or wildlife tracker to know what you’re seeing. The new “Petaluma Wetlands Field Guide,” published by the Petaluma Wetlands Alliance, can enrich the experience of a walk through the marshes, with helpful pictures and identifying characteristics of 200 different species that live in the rich and wet ecosystem on the southern end of Petaluma. They include not only birds, but mammals, reptiles, amphibians, fish, invertebrates like butterflies and dragonflies and plants.

Co-written by Parker and John Shribbs, the guide focuses on the most common plants and wildlife found along a contiguous string of parks, marshes and tidal wetlands. These include Shollenberger Park, Alman Marsh and the Ellis Creek Water Recycling Facility, with its seasonal wetlands and polishing ponds in the shape of the endangered Salt Marsh Harvest Mouse, which lives among the pickleweed.

Together, the parks encompass more than 600 ?acres along the Petaluma River connected by 7 miles of paths. Freshwater, salt water and brackish water intermingle, creating different habitats that support a wealth of wildlife. Traversing the area is an easy walk along flat trails, some handicapped-accessible. And a clear winter day is a good time to explore, with the ponds flush with the standing water on which so many plants and animals depend.

The water attracts an array of birds, ranging from Double-Crested Cormorants that dive for fish to magnificent raptors like hawks and kestrels that prey on small mammals and reptiles.

“Everyone likes to see the big charismatic waterfowl,” Parker said. “They are majestic. But the little guys are interesting, too, and they all have a story to tell and a job to do in the ecosystem. If you hear something, follow the sound and see who is making it. It might surprise you.”

The Western Fence Lizard with its characteristic blue stomach is best spotted basking on a sunny day. In spring and summer, listen for the mating ribbit of Pacific Chorus Tree Frogs, which climb trunks using fleshy, suction-cup toe pads. Seek out native Northwestern Pond Turtles among the vegetation in the side channels at Shollenberger. They disappear during dry weather, burying themselves in the mud. But in the wet season they aren’t shy. Docents have even put out logs for them to sit on. Look for the standing rushes on either side of the trails to find the channels of water where they hang out, Parker said.

Wildlife can be not only beautiful but entertaining. You might spot a river otter in Shollenberger, sunning himself before sliding down the bank to play in the mud. In the scrub and grasslands, look for Black-Tailed Jackrabbits with their gigantic ears, racing and leaping and boxing.

“The more you look, the more you see,” said Parker, who spent 20 years as a lawyer before finding her calling in the natural sciences. She has a master’s degree in marine ecology and is an assistant to a professor of invertebrate biology at the Bodega Marine Lab.

Co-author Shribbs also brought extensive expertise to curating the flora included in the guide. For years he was an industrial herbicide researcher. After moving to Petaluma 30 years ago, he became a science teacher at Casa Grande High School and took a deep dive into environmental work through the Friends of the Petaluma River and the Petaluma Wetlands Alliance, which works with local government and environmental organizations to educate the public about the ecology and value of wetlands.

Shribbs and Parker decided to keep the guide simple and user-friendly. They chose to include the most commonly found species, those that visitors are more likely to encounter on a walk. The descriptions of identifying characteristics are distilled into paragraphs written in plain language and organized by common names. Most of the photos were from the collection of the late Bob Dyer, a veteran docent who visually recorded the wetlands for 30 years.

“We didn’t want to overburden anybody with a big, huge scientific explanation,” Shribbs said. “And we translated a lot of specific scientific words into laymen’s terms so it would be easy to read, even by schoolchildren. We’re writing this for anybody who would go out and walk our parks.”

The guide includes a 30-page introduction to the history, geology and ecology of the Petaluma River, a tidal slough, and the wetlands reclaimed from old farms. Because of human disruption, many of the plants and animals in the wetlands are not native. And some, like the mute swans that have become a signature sight in the area, are problematic, Shribbs said. An interloper from Europe, introduced in the United States as an attraction in public park ponds, the mute swan has assumed a dominant place in the pecking order, taking the most and the best food and destroying the nests and eggs of other birds.

But for the time being, they are allowed to stay.

“They’re too beautiful and a favorite of the public, so there’s a bit of a conflict in policy,” Shribbs said. “There are two sides of the story, and we’re stuck in the middle as to what to do.”

The field guide, he added, offers a deeper look at a landscape that at first glance may appear very simple.