Deer Island is not exactly an island, at least not anymore. These days it is a lightly-used open space preserve in eastern Novato, centered around a hill which rises from the surrounding flatlands which were once part of the Petaluma River delta. One nice thing about Deer Island is its convenient, digestible smallness: a short and level 1.8 mile loop circles the “island,” or you can go on a central trip over the top (some 180 ft. in elevation) before returning via the loop trail on either side. The preserve is mostly covered by mixed oak woodland, but its unique position rising above seasonal wetlands and sanitary district ponds mean that it also offers semi-distant views of waterfowl and open country raptors. Compact and flat, but uncrowded and rather pastoral feeling (unlike, say, the developed and populated ambience of the Las Gallinas Ponds): Deer Island has a modest but very real set of virtues that are not always easy to find in combination so close to town.
At the trailhead, I find I almost always go right, finding myself drawn to a counterclockwise circumambulation, despite what happened to Captain Haddock that time in Tibet. Maybe it’s because I more often get there in the morning and the sunny open areas at the start of the rightward path seem more inviting in the antemeridian coolness. Or maybe it’s because the first bit to the left, running adjacent to the neighboring storage facility, is the least scenic part of the loop with its few hundred yards of rather industrial-looking backdrop. Anyways, for the sake of illustration, I’ll describe the loop in this counterclockwise direction.
You’ll start out with a brief excursion through open grassland. Some of this is seasonally inundated, as in the drought-breaking winter of 2016-17, but most of what you see is set off by levies from tidal action around lower Novato Creek. (A 2017 ballot proposal would have raised funds for a needed rebuilding of levies in a new position that would have increased the amount of tidal wetland and provided legal public access to the ponds and wetlands, but it was defeated decisively and it remains to be seen if any alternative funding for the project will be found.) These drier grasslands host a variety of sparrows in winter, including the ubiquitous white-crowned and golden-crowned sparrows, but also the subtly distinctive Savannah and Lincoln’s sparrows. You might also see a flock of dull-colored and portly birds take flight from among the grasses, then be struck by brilliant gold if they turn towards you to reveal their front sides. These are western meadowlarks, who even in winter (when they are most abundant here) can occasionally be heard singing like more musical blackbirds, with some of the same liquid fluting quality of their darker relatives. In winter, check low posts for Say’s phoebes and higher trees and towers for raptors like merlins or peregrine falcons as well as the year-round red-tailed hawks.
Woods
As you move gradually into the oak woodland, you’ll start seeing a greater variety of small songbirds. Common year-round birds include dark-eyed juncos, oak titmice, chestnut-backed chickadees, white-breasted nuthatches, bushtits, brown creepers, and spotted towhees, as well as most of our several woodpeckers including downy, Nuttall’s, and acorn woodpeckers. In spring, listen for the musical songs of Bewick’s wrens, purple finches, and migrant songbirds like orange-crowned warblers and warbling vireos, periodically punctuated by the loud ker-BRICK of the ash-throated flycatcher.
In winter, the woods may seem quieter without the songs of spring, and because of many songbirds’ habit of joining up into mixed species flocks outside of the breeding season. With birds concentrated in these flocks and vocalizing less, you might pass through some areas that seem almost silent – until you run into one of these flocks that suddenly surround you with a multitude of different birds. One of the most common winter constituents of these flocks are ruby-crowned kinglets, who join resident birds like chickadees, titmice, creepers, bushtits, and juncos in exploring the oaks for insects and other food. The other very noticeable winter songbird making short insect-catching sallies from the oaks are yellow-rumped warblers, who are often found in loose groups of their own species among the more open deciduous oaks.
Water
Towards the far end of the island are some sizeable sanitary district ponds, which tend to offer the biggest variety of water birds, though admittedly at some distance. Some common ducks and waterfowl to sight here in winter include northern pintail, northern shovelers, bufflehead, ruddy ducks, coots, pied-billed grebes, and Canada geese. Sometimes a large squadron of white pelicans may arrive for a session of synchronized feeding. This part of the preserve is also a good place to watch out for raptors: the wide open seasonal wetlands offer good hunting for kites, kestrels, and harriers while also attracting occasional visits from the exciting winter raptors like the big ferruginous hawk, golden eagle, merlin, or peregrine falcon. The grassy slopes dotted with coyote bush leading down towards these ponds are often a good area in summer for house wrens or blue-gray gnatcatchers. As you continue along, you’ll approach closer to a channel – check for herons, egrets, and the occasional otter as you get windows of visibility through the trees.
Woods again
Soon, though, you’ll head back into the woods on the north side of the hill, averaging darker and denser than those on the first half of the walk, with more patches rich in live oaks and bays. (Periodically, depending on the contour of the “island,” you will open up into lighter groves of the round-lobed valley oaks and periodic patches of blue and black oak.) Pass by the one notable intersection of the loop trail where the De Borba trail heads uphill to climb over the modest summit, reaching slightly drier areas with madrones and more deciduous oaks. Continuing on the loop trail, you’ll find yourself in a darker, moister area where buckeyes unfurl their five-fingered leaves in early spring and the great Octopus Bay of Deer Island spreads its sprawling tentacles. I like that tree. These darker woods will still host those roaming winter flocks mentioned above, and tend to be the better areas for seeing a certain class of birds that prefer denser forests, like Steller’s jays, Townsend’s warblers, hairy woodpeckers, and the occasional golden-crowned kinglet. A lovely springtime stretch of green grass, blue skies, and spreading valley oaks relieve the darkness before you head in for the final short stretch among the bays and ferns as you return to the entrance.
Practical Details
Getting There: From Hwy 101 in Novato, take the exit for Atherton Ave east 1.7 miles. Turn right onto Olive Ave and left onto Deer Island Ln. Gate and small parking area will be on your right. For GPS, use the address 320 Deer Island Lane, which corresponds to the building closest to the trailhead parking area.
Getting Around: A short and level 1.8 mile loop circles the “island,” or you can go on a central trip over the top – some 180 ft. in elevation – before returning via the loop trail on either side. Those are your options! If you go over the top, stay on the clear De Borba trail, as there are a few side trails that peter away to dead ends or steep descents. The official map from Marin Open Space may be moderately helpful in understanding that aspect of the layout, but the outer loop is pretty unambiguous and poses minimal navigational challenge.
Rules & Access: Deer Island is a Marin County Open Space Preserve and so is open to free public access 24 hours a day, but lacks amenities like restrooms or tables. Leashed dogs are permitted on trails.
Birds: You can see recent sightings and seasonal bar charts at Deer Island’s eBird hotspot page.
Top photo: Deer Island in February freshness