Indian Warriors (Pedicularis densiflora) blanket the ground under a small grove of oaks at Jasper Ridge Biological Preserve, Stanford University. Although they can grow independently, these hemiparasites often steal water and nutrients by attaching to roots of nearby shrubs and trees.
The Anise Swallowtail (Papilio zelicaon) compensates for demise of habitats containing its native food plants by feeding on two introduced plants common in the Bay Area. These plants are the licorice-scented Anise (Foeniculum vulgare) and the spotted-stemed Poison Hemlock (Conium maculatum), which though deadly to humans, does not affect the Anise Swallowtail caterpillars.
Oak apple galls are tumor-like growths on white oaks such as the Valley Oak (Quercus lobata). Initially reddish-green, the galls age brown, or sometimes blackish from moldy soot, and after several years fall from the tree. Tiny holes mark the exits of California gall wasps (Andricus quercus californicus) and their uninvited comrades, who used the gall for free room and board.
Distinguished by its bright yellow feet, the versatile Snowy Egret (Egretta thula) often waits motionless, spearing unsuspecting fish with its dagger-like beak. But this egret also employs a number of other tactics. For example, the Snowy Egret may use one foot to stir the water and flush out prey like crayfish. Or the adept feathered fisherman may form an umbrella with its wings to shade the water. The cover not only cuts glare but attracts fish, which, ironically, associate shade with safety.
Weighing just over a quarter pound, the petite Burrowing Owl (Athene curicularia) roosts at the front of its burrow, conveniently excavated by the prior inhabitant, a ground squirrel. During hunting forays, mainly after dusk falls, the Burrowing Owl takes prey ranging from insects to rodents and bats. Occasionally this owl sunbathes during the day, sprawling face first and spreading its wings to capture the warming rays.