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Mitchell Canyon is a Great Place to Hike

Oh, the Species You Can See!

by Dan Sandri

Mitchell Canyon is a Great Place to Hike

Mount Diablo Globe Lily by Dan Sandri

Mitchell Canyon, on the north side of Mount Diablo State Park, features varied habitats with a great diversity of plants and animals. This includes uncommon-to-rare species, disjunct populations (populations separated from other populations of the same species, often by great distances), and endemic species (species not found elsewhere).

Near the soon-to-be Mitchell Canyon Education Center, Mitchell Creek winds through riparian habitat, chaparral, oak woodland, grassland, and some pine forest. Each of these habitats has its own population of plants and animals that may not be found in the others. Below, MDIA Board member Dan Sandri features a few fascinating plants and animals that are found along Mitchell Creek.

Mount Diablo Globe Lily, aka Mt. Diablo Fairy Lantern  (Calochortus pulchellus) is a rare species of flowering plant in the lily family known by the common name Mt. Diablo fairy-lantern or Mount Diablo globelily. The Mt. Diablo fairy-lantern is endemic to California, and is mainly restricted to Mount Diablo of the Diablo Range. There are historical occurrences in the North California Coast Ranges, within Marin, Solano, Napa, and Humboldt Counties. Mitchell Canyon is a prime location to see this beautiful flower.

Complex Physocephala marginata (Family Conopidae):

Physocephala marginata is a species of thick-headed fly (or complex of very similar species) in the family Conopidae. These flies are endoparasitoids during their larval stages.

Hosts include mainly wasps and bees. They possess a ventral genital plate that is used to pry apart the abdominal sclerites of the host bee or wasp for egg insertion; eggs are deposited in the abdomen by females. After the host dies, an adult Conopid fly emerges from the dead insect.

California Bumble Bee (Bombus californicus) is a mid-sized bumble bee that is very uncommon on Mount Diablo. It can be seen occasionally in Mitchell Canyon. It is mostly black in color, with black between wing bases and yellow hair in front of the wing bases. It has a black face (no yellow hairs on face). Its 4th abdominal tergum is always yellow.

The California Bumble Bee is a flower generalist, and on Mount Diablo has been documented on hedgenettles, Western Wallflower, thistles, lupines and Pacific Pea.

This is a dark bumble bee and thought by some to be a subspecies of Bombus fervidus. Eusocial, they nest primarily underground in abandoned rodent nests, or sometimes in grass just above  ground. Thought to have suffered from competition with other bumbles, such a B. vosnesenskii.

A Fishfly - (Neohermes filicornis) These fishfly adults are sometimes seen at lights at places such as the Mitchell Canyon Visitor Center. These eye-catching critters belong to a small group of insects called the Megaloptera, or fishflies. While most fishflies are remarkable for their large size, this species is extra cool for its stream-inhabiting larvae, sometimes known as hellgrammites, that take 3–4 years to develop. The larvae in Mitchell Creek often have to endure cycles of stream drying, and they do so by burrowing into the streambed. Males like the one shown here have bead-like antennae. In females, the antennae are narrower, smooth, and hair-like.

Gorgon Copper (Tharsalea gorgon) Males have a coppery-brown upperside with bright reddish-purple tinge; females are lighter copper, with cream and black spots (this is a female). Eggs are laid singly on host flower stalks and hatch the next spring. Caterpillars eat leaves of buckwheat plants. These butterflies have one flight from May-June.
Range: Southern Oregon through California to Baja California.

Wide-striped Painted-Dark Bee (Stelis laticincta, Family Megachilidae) is an uncommon species of cleptoparasitic cuckoo bee in the family Megachilidae. The description comes from the cuckoo bird-like behavior of many distinct bee lineages in which females, instead of constructing their own nests and collecting their own pollen, lay their eggs inside the nest of a different pollen-collecting bee species. A cleptoparasitic larvae is one that primarily derives nutrition by consuming the host's food (the pollen ball), rather than deriving nutrition from consuming the host.  Stelis laticincta is a cuckoo resin bee - its host is a resin bee in the leafcutter genus Megachile. This bee species appears restricted to the pacific region of the western United States. Its name, laticincta, means "wide-belted," referring to the broad black and yellow stripes of the bee.

Checker Lily (Fritillaria affinis affinis) aka Rice-grain missionbells has a leafy flowering stalk that reaches up to 4 ft. and carries one to twelve, pendent, cup-like flowers. The flowers are checkered with brown and green, sometimes with purple and yellow inside. 

Plants may skip a year or two from flowering, making only a single, broad, tongue-shaped basal leaf during those times. This plant is found from Southern British Columbia, south on both sides of the Cascades in Washington, on the west side in Oregon, to Southern California.

California Pocket Mouse (Chaetodipus californicus) is a rarely seen nocturnal rodent that inhabits the chaparral and grasslands of Mount Diablo and feeds mainly on seeds. This specimen was seen and photographed by Dan Fitzgerald while he was leading his monthly Birds, Butterflies and Blooms hike in Mitchell Canyon. 

This pocket mouse, named for the external pockets they have in their mouth for grain carrying, is found in California from the San Francisco Bay area south into Baja California. It is also found in California’s Sierra foothills. There are eight subspecies.

Gray foxes (Urocyon cinereoargenteus) are the only foxes native to the Bay Area, and are about the size of a small-medium dog (about 8-10 pounds on average), with shorter legs and a longer torso than the non-native red fox. They have a long tail with black on the top and a black tip (red foxes have white tail tips). Gray foxes have peppery gray coats with some red/brown highlights. 

If you see a fox on Mt. Diablo, it will probably be a gray fox, and you will likely see it in the early morning or evening, as Gray foxes are secretive, crepuscular and nocturnal.

Gray foxes are thought to have evolved millions of years before other foxes. Equipped with strong, hooked claws, gray foxes climb high into trees to hunt squirrels and to avoid predators, such as coyotes. FYI: red foxes are not tree climbers. Gray foxes also eat rodents, rabbits and birds. 

A gray fox pair may mate for life, and they can live to be 6-10 years of age. Pups are born in the Spring and are on their own in 9 months.

Will you join us in helping to build the new Mount Diablo Education Center, so that for the first time, school buses can safely bring students from any neighborhood in Contra Costa County to experience the mountain? Donate today at:

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