National Wildlife Refuge System

Sand to Save a Butterfly

The sand dune habitat at Antioch Dunes National Wildlife Refuge is being restored to help save the endangered Lange's metalmark butterfly.
Credit: USFWS

December 12, 2013 - There is only one place on earth where the endangered Lange’s metalmark butterfly lives: a tiny remnant of sand dune habitat along the shore of the San Joaquin River in California.  A new agreement between Antioch Dunes National Wildlife Refuge in central California and the Port of Stockton is aimed at restoring and protecting that sandy habitat.

When it was established in 1980, Antioch Dunes Refuge was the smallest national wildlife refuge in the country and the first whose mission was to preserve plants and insects. Last year, the refuge publicized its need for large quantities of sand for dune restoration. The Port of Stockton responded. The Port and the Army Corps of Engineers regularly dredge the San Joaquin River as a shipping channel.

“We were looking for large quantities of sand,” said the refuge’s wildlife resource specialist Louis Terrazas, “and they were looking for a place to put it. It was a match made in heaven.”

Free Sand

The Antioch Dunes evening primrose was featured on a U.S. postage stamp of endangered flora in 1979.
Credit: Ivette Loredo
The Contra Costa wallflower is one of two endangered flowers that will be planted along restored dunes at Antioch Dunes Refuge in California.
Credit: Rachel Hurt

The refuge will build up its dunes with free sand pumped directly from the river.   The first load of 40,000 cubic yards of sand was pumped in October and it will be seeded with native plants in the spring – including two other endangered species, the Antioch Dunes evening primrose and the Contra Costa wallflower. These two flowers, as well as naked-stemmed buckwheat - the only host acceptable to the Lange’s metalmark butterfly for egg-laying – have been crowded out by invasive weeds, especially winter vetch that climbs over the buckwheat and smothers it. Now the new sand is intended to smother the winter vetch and other invasives, giving the native and endangered species a chance to thrive.

So far, Lange’s metalmark butterfly has only been seen in one of the two units of Antioch Dunes Refuge.  The dredging is adding sand to the second unit. By spring 2015, the plan calls for Lange’s metalmark butterfly eggs to be introduced to this second unit. The eggs are being propagated by the Urban Wildlands Group, a private organization dedicated to protecting species and habitats in urban areas. “There is the possibility,” reports Bay Nature magazine, “that not only a landscape, but an ecosystem, can be rebuilt with every grain of sand.”

The Friends of San Pablo Bay National Wildlife Refuge sponsored the publication of a new children’s book about Lange’s metalmark butterfly.  Sardis and Stamm, by Matthew P. Bettlheim, illustrated by Nicole M. Wong, is named for the two units of the Antioch Dunes Refuge.  The Friends and the refuge have scheduled a dune tour and book reading on January 11. Details here.

Sand dredged from the San Joaquin River is pumped onto the Antioch Dunes Refuge to restore sand dune habitat for endangered plants and insects.
Credit: Louis Terrazas/USFWS
Last updated: December 13, 2013