Friday, October 28, 2016

Shorebird Loop Trail in Humboldt Bay National Wildlife Refuge

Board walk: beginning of the Shorebird Loop Trail
Beginning of the Shorebird Loop Trail at the visitor center
The 1.75-mile-long Shorebird Loop Trail in the Humboldt Bay National Wildlife Refuge is one of many short trails that can easily be reached for a nature stroll in coastal northern California [1]. It is a level lasso-loop trail: it includes an out-and back section to Long Pond and a loop section (the lasso nose) that surrounds the pond and brings you close to Hookton Slough and Teal Island in the South Humboldt Bay. November through April are the best months to watch the impressive variety of waterbirds, including migratory shorebirds. The best day hours for wildlife watching are when dawn or dusk coincidences with the one to two hour window before or after high tide [2]. 

The visitor center and trailhead is at YOU ARE HERE

The trail begins as a board walk at the visitor center. I recently walked the trail one afternoon in summer, not the recommended season for bird-watching. Various interpretive panels along the trail are dedicated to the natural history and the human history of the marshlands. For example, one panel features northern harriers, formerly called marsh hawks, which hover low over marshes and sloughs in search of prey. Then there are peregrine falcons who dive down on their prey at speeds of up to 200 mph (322 km/h).

Marsh lotus, an invasive species from Europe
From the loop trail, I saw strips of yellow pillows, which I was informed at the visitor center are mats of marsh lotus (Lotus pedunculatus). This freshwater-marsh flower from Europe is on the list of invasive species [3].

The Humboldt Bay is a stopover for fuel and energy—not only for tourists, but for migratory birds as well. The latter typically fly north to breed during the Arctic summer and return to warmer wintering regions far south from Humboldt Bay.

Eroding bucket of the Jupiter dredge, once used to dig through marshes and mudflats

The marshlands of Humboldt Bay were changed by dredging. The eroded metal bucket next to the trail along the slough south of Teal Island is a left-over from the marshes-to-pastures days:

This piece of metal is a bucket from the Jupiter dredge [built in 1926 by the Stockton Iron Works in California's Central Valley]. From the 1930s through 1970s, it was used to dig through salt marshes and mudflats to create a system of dikes in the South Bay, transforming wetlands into pasture. This practice reduced the bay's estuary by 40 percent.

Since 1971, when the Humboldt Bay National Wildlife Refuge Complex was established, the agricultural development trend has been reversed to habitat restoration “to conserve precious habitat for the great diversity of birds, mammals, fish, amphibians, invertebrates, and plants that occur in the Humboldt Bay area” [4]. The Shorebird Loop is a relaxing trail, along which to catch a first glimpse of both the restoration efforts and the estuary biodiversity.

Long Pond

Getting to the Shorebird Loop Trailhead
From Highway 101 south of Eureka, take exit 695. Go north on Refuge Entrance Road, parallel to Hwy 101, for about two miles, to where the roads bends west. After another mile, you will see the visitor center to your left. Walk through the open passage onto the board walk and begin your hike on Shorebird Loop Trail.

References and more to explore
[1] Jim Hight: Seven Trails In Your Backyard [].
[2] Humboldt Bay Wildlife Refuge [].
[3] U.S. Fish & Wildlife Service/Humboldt Bay: Invasive Species Management [].
[4] See the section Refuge History at

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