The dynamic dune system of the Antioch Dunes hosts a unique assemblage of flora and fauna, which has attracted naturalists for more than a century. Albert Kellogg, cofounder of the California Academy of Sciences, was the first to botanize the dunes in 1869. Beginning in 1929, the remarkable insect fauna attracted entomologists from the Academy and the University of California. Between then and 1982, entomologists continued to revisit the dunes every year (excepting 1931, 1943, 1970, and 1980) making it a veritable hot spot for Bay Area entomologists. During that time, 376 insects were recorded at the dunes, of which only 219 were recollected during survey efforts in the early 80’s, suggesting some 157 insect species have since disappeared. All told, their collecting efforts led to the discovery of 27 new taxa of insects. Several of these species were recorded then for the first and last time, remembered today only by the preserved specimens collected during these early forays. During the most recent survey effort, performed between 1995 and 1997, a total of 249 insect taxa were recorded. However, these taxa represented only 35% of the insect species recorded previously during the last extensive survey effort between 1976 and 1982.
Eight insects are—or were—endemic to the Antioch Dunes:
Antioch robberfly (Cophura hurdi) – Extinct
yellow-banded andrenid bee (Perdita hirticeps luteocincta) – Extinct
Antioch Dunes shield-back katydid (Neduba extincta) – Extinct
unnamed plasterer bee (Colletes turgiventris) – Unknown
Antioch weevil (Dysticheus rotundicollis) – Unknown
Antioch Dunes halictid bee (Lasioglossum antiochense) – Extant
Antioch andrenid bee (Perdita scitula antiochensis) – Extant
Lange’s metalmark butterfly (Apodemia mormo langei) – Extant
Of these, three species are extinct, the status of two are unknown, and three are thought or known to still survive at the dunes today. But it was the dwindling numbers of the eighth—Lange’s metalmark butterfly—that helped bring the refuge into existence.
The Lange’s metalmark butterfly was first listed as a federally endangered species in 1976. That same year, the Antioch Dunes were designated as “critical habitat” for the species. In 1986, Service personnel and volunteers counted a total of 187 Lange’s at their population’s annual peak. By 1999, the peak population count hit 2,342 butterflies, the highest count recorded to date. But in 1999, a trespasser’s campfire along the riverfront burned 10 acres of prime Lange’s habitat in the Stamm. In the wildfire’s wake, peak Lange’s counts have steadily declined from 1,185 in 2000 to 521 in 2003, 452 butterflies in the fall of 2004, 232 butterflies in 2005, 45 butterflies in 2006, and an alarming 28 in 2010.
The dune’s curiosities include the oft overlooked California legless lizard and California horned lizard (familiarly, the “horned toad”), both of which bury themselves in the sandy soils. Other amphibians and reptiles seen over the years include western toads, fence and side-blotched lizards, western yellow-bellied racers, gopher snakes, and Northern Pacific rattlesnakes. Common inhabitants among the other taxa include belted kingfishers, northern harriers, a suite of waterfowl, beavers and muskrats along the water’s edge, and resident skunks, raccoons, ground squirrels, and gray and red foxes.
Learn more about the:
To learn more about the plants of the Antioch Dunes, click here.