It was a wet and dreary morning when a friend and I turned into one of the canyons that funnel storm runoff down the slope of Mt. Tamalpais and into Bolinas Lagoon. We parked near the old white clapboard ranch house and walked to a clearing for a view of the thickly forested canyon. When we got to the top, we found what we were looking for. Standing it front of us was a Douglas fir — standing high above its neighboring trees — that seemed decorated like a Christmas tree with many large fluffy white ornaments.
Most of the Great Egret and Great Blue Heron nesting sites around the San Francisco Bay are gone, but this quiet canyon near Stinson Beach in Marin County is one of the largest rookeries on the West Coast. These elegant and graceful birds return to these treetops every spring, nesting in close-quarter colonies. Their bright white plumage was clearly visible against the Douglas fir’s dark foliage. It was quite a sight.
Fifty years ago, the Audubon Society recognized the importance of this canyon, and purchased the property and turned it into the Audubon Canyon Ranch. Afterward, the ranch organization grew to protect additional sensitive properties, and renamed the property to the Martin Griffin Preserve to honor the man instrumental in saving it.
While there we met Gwen Heistand, the preserve’s biologist, who guided us to the Kent Trail. We walked through a dense forest of redwoods, Douglas firs, oaks and bay trees watered by fog and rain that regularly drench these slopes.
We reached Henderson Overlook in a matter of minutes. There, we had a bird’s-eye view of the Great Egret nests. With the aid of powerful spotting scopes, we were able to get an intimate look at the birds incubating their eggs in huge twig-built nests.
Great Egrets begin arriving in mid-March, and by mid-April, it is peak laying time. At last count there were 50 nests in the tree below us, though in seasons past, they have had as many as one hundred nests. Nest sizes usually include three to four eggs.
The only birds currently in the canyon are the Great Egrets, usually the Great Blue Herons traditionally nest there. But in recent years, the herons have moved to nearby Kent Island in Bolinas Lagoon, a short distance beyond the mouth of the canyon.
While the birds are the headline act here, they are not the only attraction. Douglas Irises, ranging in color from bright purple to a pale yellow, decorated the trail. And the few narrow views we saw toward Bolinas Lagoon opened to a vast one at the Clem Miller Lookout.
Seeing an occasional lone egret in a field is a great sight, but watching these elegant and graceful birds in such numbers is a stirring treat. And the process has just begun. Over the next couple of months, the eggs will hatch and the chicks will take their first flight.
Martin Griffin Preserve is open during the nesting season on weekends and holidays from 10 a.m. to 4 p.m. or0 by appointment (www.egret.org). It’s free, but they would appreciate a donation.
