Seasons in the Valley: Winter at San Joaquin River National Wildlife Refuge

While snow blankets the high Sierra to our east, and sunny days prevail along the coast to our west, California's Great Central Valley experiences the unique winter of a Mediterranean climate.  Nights can be thick with tule fog and days dreary and gray with low skies; on other days, skies may be high, clear and bright azure, with freezing nights preceding mornings white with wintry frost.  It may not be the postcard winter scene (no stunning red cardinals against a backdrop of snowy conifers here), but it is wintertime nonetheless, with its own beauty to be found in the quiet landscape.

White-tailed Kite, San Joaquin River NWR

Winter is a good time to look for raptors, like the beautiful White-tailed Kite (Elanus leucurus) pictured above.  Watching these stunning birds hunt, hovering or "kiting" in mid-air while they scan the ground for rodent prey, is a real treat.

Another marshland hunter, the Northern Harrier (Circus cyaneus), is readily identifiable by its white rump patch and owl-ish face.  They typically fly low over wetlands and adjacent grasslands in search of rodents and smaller birds.  Where Northern Harriers are present, be sure to be on the lookout for Short-eared Owls, which overwinter in the Valley and share the harrier's habitat preferences.

Northern Harrier, San Joaquin River NWR

Similar in appearance to it's larger cousin the Cooper's Hawk, Sharp-shinned Hawks visit our area only during the winter months.  Look for their blue-gray upper parts, reddish barred chest and pencil-thin legs.  Sharp-shinned Hawks feed predominately on small songbirds.

Sharp-shinned Hawk, San Joaquin River NWR

Winter is the season for waterfowl and shorebirds as well.  A plethora of duck species can be found on wetlands up and down the Central Valley.  Less common and often restricted to more secluded habitats are Hooded Mergansers, named for the impressive white crest sported by the males.  Also be on the look out for other diving ducks, like goldeneye, Ruddy Ducks and Bufflehead.  Along reedy shores and mudflats, keep an eye out for shorebirds like dowitchers, snipe, yellowlegs, sandpipers and plover.

Hooded Merganser male and two females, San Joaquin River NWR

A number of songbirds spend winter in the Valley as well.  One of our more common winter visitors is the charming Dark-eyed Junco, common on Christmas cards across the continent.  These are perhaps our most distinct sparrow.  Look for their gray hoods, pink bills, and white outer tail feathers as they fly low from shrub to shrub.  Also listen for their high, short "chip" contact calls as they forage in flocks.

Dark-eyed Junco

As the last of autumn's leaves are blown from the trees, birding becomes a little bit easier.  Birds that are often difficult to see (and even harder to identify) now perch in bare branches.  Count how many little brownish sparrows you can find in valley grasslands and woodlands: White-crowned, Golden-crowned, Fox, Lark, Savannah, Vesper, Lincoln's, and Song Sparrows are all out in force during the winter, gleaning seeds from dried weed stalks and leaf litter.

Savannah Sparrow, San Joaquin River NWR

Considerably more difficult to see than birds, mammals are often nocturnal and secretive.  Diurnal tule elk and mule deer are typically conspicuous, as are brush rabbits, cottontails and jack rabbits.  There is a tree along the Pelican Nature Trail with an inviting cavity that we always check for owls or other critters.

Looking a little closer (and zooming way, way in with my camera) I was surprised to see one dark eye peering out at me from inside the tree.  Warm and snug in the tree cavity, protected from the cold weather and blowing winds, was a raccoon!  Its masked face, dark eye and whiskers are just visible in the photo below.

Raccoon at San Joaquin River NWR

River otters are diurnal residents of the San Joaquin River, and are often spotted along sandy riverbanks or in the many side channels and sloughs that extend fingers into riparian areas.  Watching the gambols of river otters is always an enjoyable experience.  These three otters were busy rolling, twirling and tumbling in the water, heedless of the cold.

River otters at San Joaquin River NWR

A walk through the Valley's winter habitats may turn up all of these as well as other exciting discoveries hidden in the subdued, dun-colored landscape.  While I revel in the beauty of bright spring green and bask in the many-hued gold of autumn, there is an unmistakable sort of peace and tranquility to be found in winter's quiet pallet.

Night falls early during the winter months, but dusk can be the best time for viewing wildlife.  Wetlands that host large numbers of overwintering geese and Sandhill Cranes come alive as flocks of birds several thousand strong fly in to roost for the night in the safety of the water.  Owls wake for their nightly hunt, and their calling usually begins as the light fades in the early evening hours.

A walk at San Joaquin River National Wildlife Refuge (or in other valley wetland, grassland and riparian areas) turns up a host of neat discoveries.  So bundle up, and get outside!