Our Chapter

Mammals in the wild are elusive.  With their acute senses of hearing, smell and sight, they are alert to our presence long before we ever come near them.  We walk along county park trails gazing at birds with our binoculars, never realizing that a deer stood on the path moments before us or that a raccoon is asleep in a nearby fallen log.

One of my favorite mammals at the SJWS is the Coyote because, unlike other mammals, evidence of its presence abounds.  Look closely and its tracks are everywhere in the dirt and soft mud around the ponds.  Its large grayish scat (droppings) litters our trails, forcing us to take notice and step gingerly around it.  Curious visitors notice the scat is full of fur and bones and sometimes seeds and feathers.    Participants in our summer Bat Walks are occasionally treated to coyote sounds.  When I hear a distant siren, I urge everyone to be still and listen.  Soon, the yips and howls of nearby coyotes break the silence of the marsh, the perfect nighttime serenade!

The Raccoon is another mammal whose presence is known by its tracks and scat.  When the pond levels are lowered, those little hand-shaped prints are common on the exposed mud as the raccoon searches for crayfish, frogs, fish, insects, and fruit.  One large raccoon took up residence underneath the front porch of the Duck Club for years.  One summer, we wondered what inconsiderate person was repeatedly leaving trash scattered in front of the Duck Club.  The naturalists and I discovered the culprit as we finished a Bat Walk.  A raccoon clung to the side of the trash can, staring at us before disappearing inside and then reappearing with a trash dinner.

Twice I have seen the Long-tailed Weasel at our marsh.  While leading a Children’s Birdathon in 1995, we noticed something very long and tan and low to the ground racing between Ponds D and E.  "That’s not a ground squirrel," I thought.  The girls and I were so excited about the encounter that we momentarily forgot our birding competition.  Long-tailed weasels are carnivores that hunt day and night, searching runways and burrows for mice and voles.

Santa Ana schoolchildren love our Audubon Cottontail Rabbits.  If they see a cottontail while listening to my welcome on the school bus, I cannot compete with their shouts of "Conejo! Rabbit!"  Cottontails stick close to the edges of the meadow behind the Duck Club.  Their long ears are alert for danger, and they are ready to dash to cover if threatened.  Sometimes at dusk the lawn appears to undulate with the movements of so many rabbit bodies.  They do a great job of mowing the grass around the buildings!

The California Ground Squirrel is diurnal (active during daylight), and can cause damage to the clay-lined ponds with its digging and burrowing. We need more Golden Eagles to keep their numbers down.

The SJWS is home to a variety of Rodents we never see such as voles, pocket mice, white-footed mice, and non-native house mice and rats.  We can guess at their presence because a nesting Barn Owl raised SIX chicks in spring 1999.  There has to be abundant rodents on-site to feed that many hungry owl mouths!  Did you know that mice will gnaw on bones from carcasses for the calcium?

I was jealous of Irvine Ranch Water District employees who reported seeing a large Bobcat as they arrived for work at 6:30 a.m.  I had never seen one.  Until one afternoon while passing Carlson, I noticed a very strange-looking dog crossing the road from the marsh.  It was leggy and its face appeared pushed in and the tail was short; that’s no dog!  How exciting to know that our little marsh could be home to a bobcat.  Unfortunately and to my utter dismay, it ended up road-killed several months later.

Leaving the marsh late one winter night, I spied a small, black and white, cat-like body gliding ahead of me on the road.  With its boldly patterned fur, the Striped Skunk cannot be missed. It digs for insects and grubs, leaving behind small depressions in the ground.    A population of striped skunks needs at least 640 acres, so the SJWS is unlikely to host them.

At least 2 species of bats are found at the SJWS, the Mexican Free-tailed Bat and the Yuma Myotis Bat.  Both are small insect-eaters that are active shortly after dusk.  The Mexican Free-tailed Bat has a flight that is straight and rapid due its long and narrow wings.  It usually feeds on moths at high elevations so we don’t see it.  Yuma Myotis, however, with its shorter and broader wings, has a swift and erratic flight as it forages low over water in search of aquatic emergent insects.  SJWS has plenty of permanent water and midges, flies and small moths, so Yuma Myotis is almost always seen on our summer Bat Walk programs.  Both species roost on bridges (Jamboree at Upper Newport Bay) and buildings (houses along University Drive) in addition to natural structures. Our wish list includes installing bat houses in hopes of encouraging them to not just "eat and run" but to live here also!

The SJWS is closed from dusk to dawn, allowing our wild mammal residents to freely roam the sanctuary without disturbance as they hunt prey, seek mates, and raise their young.  On a few summer nights, however, you can visit their nocturnal territory for a glimpse of how they live.  Join us to celebrate our TEN YEARS AT SJWS; sign-up today for our ever-popular Summer Bat Walks and our new Sunset Walks; both highlight the mammals of the marsh.