Text by Victoria Schlesinger; images by Jane Kim.
SPOTLIGHT SPECIES: OCHRE SEA STAR
Arm days
Perhaps this spring you’ll make it to the coast and find yourself calmed by the waves cresting and crashing ashore, a drama that repeats and repeats. But consider the sea star: relentless pounding as a way of life—not so tranquil. Scientists have examined how ochre sea stars (Pisaster ochraceus) nonetheless hold on. As one of the largest rocky intertidal species, they take an outsize beating. One study found that the stars changed shape over three months in response to their exposure to waves. The greater the waves’ velocity, the more slender and lighter-weight the star’s arms become. The thinking goes that a wave’s lift and drag lessens with this arm size. A skinny-armed pisaster is telling you something about the waves on that bit of coast.
Voices from the deep
In late spring, the plainfin midshipmen (Porichthys notatus) swim from the depths of the Pacific to the intertidal shores of California and the muddy bottom of San Francisco Bay and begin to sing. These male choristers are beautifully, ridiculously ugly with a wide frog mouth, dagger teeth, and weenie backside. They sing (by rapidly contracting the muscles around a swim bladder) so females, equally inelegant, can find them. The singing, especially when in chorus, has been compared to the sound of a B-29 bomber, so loud it can be heard from shore.
Tiny beauties
Some say they smell like musk, others say chocolate. At a distance they may seem ho-hum, but up close the dime-size wildflowers called bird’s-eyes (Gilia tricolor) are a jazz combo of color when they bloom each spring. They are beloved in cottage gardens, but endemic to California grasslands and foothills, thriving on poor serpentine soils that inhibit competition from invasive species. A UC Davis study found that bird’s-eye seedlings do better when there’s less leaf litter. It’s likely that fairy longhorn moths, which in fact have long hornlike antennae, enjoy bird’s-eyes, as do bees, bats, butterflies, and hummers.
Bombus
The high-pitched buzz of a yellow-faced bumblebee (Bombus vosnesenskii) is the music of a spring meal to come. Our notice of the distinct sound has followed bumblebees across centuries, reflected in its Latin name, Bombus: to boom, hum, or buzz. The noise emanates from the bee’s vibrating thorax muscles, which shake loose tasty pollen grains from the male flower that bumbles inadvertently carry to female flowers, pollinating them. Sometimes those blooms belong to a California lilac bush (Ceanothus spp.), sometimes to our tomato plants.
Whistle while you work
The bubbly, bobbly, whistling song of black-headed grosbeaks (Pheucticus melanocephalus), sometimes described as that of an American robin that has thrown back a few, fills the dawn and dusk hours of spring. Migrating from Mexico to edge habitats and gardens in California and much of the West, males and females both sing their winsome tunes—the male to warn off intruders from his territory, and the female to communicate with her mate and young. Incubating, feeding, and fledging their chicks together, the pair has a lot to sing about.
The ears have it
The ears of a black-tailed jackrabbit (Lepus californicus) can range between 4 and 5 inches long. That’s a lot of ear. Those lengthy, somewhat translucent, cupped hearing aids may be able to pick up frequencies as low as 62 Hz—think low bass drum—and as high as 27 kHz—pretty much above a human’s upper range. Our local jackrabbit is enjoying a spring concert we can’t even hear.
