| The Magazine of the CALIFORNIA ACADEMY OF SCIENCES |
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Naturalist's Almanac What to look for this Winter January A single Pacific chorus frog emits a cautious "krek eck" and soon dozens of his subordinate rivals join in for an evening of mate-attracting song. Formerly known as tree frogs, Pacific chorus frogs are California's most wide-spread amphibian, ranging from Mojave Desert oases to Sierra peaks. Anytime between January and July when local moisture and temperature are just right, chorus frogs migrate to creeks, puddles, and pools to mate. Females spend only a day or two at these sites, but male frogs hang out for a couple of weeks, singing to establish their territory-a circle no larger than a throw rug-and to advertise for successive mates. If you live near a creek, pond, or even a vacant lot full of puddles, open your window on a moist winter evening and listen for the symphonic choirs of these silver dollar-sized amphibians. Elephant seals arrive on California beaches between December and February. Bulls pull in first and immediately go to battle with one another to establish dominance and rights to the biggest harems. No other California wildlife drama can beat the bloody beachside clashes between these massive, bellowing animals-a mature bull easily outweighs the entire eleven-man defense of the San Francisco 49ers. Females give birth three to four days after arriving, with peak activity during the last two weeks of January. Pups nurse for less than four weeks and are abruptly weaned when their mothers depart for the deep sea just days after mating. The best elephant seal viewing area is 55 miles south of San Francisco at Ano Nuevo State Reserve. Access by guided tour only during breeding season. Reservations recommended. (650) 879-0227. February Coyote pairs breed from January to March. Before their pups are born, the pair usually prepares several den sites. They prefer south-facing slopes for dens, digging new holes into the dirt or using abandoned badger burrows. If a den is disturbed or if the pair feels threatened, they move quickly to one of their reserve sites. Join thousands of volunteers across the country and count the number and kinds of birds in your backyard during the Fourth Annual Great Backyard Bird Count, Feb. 16-19. The count yields a treasure trove of data for its sponsors, the Audubon Society and the Cornell Lab of Ornithology. The job is simple: observe the birds in your yard or neighborhood for at least 15 minutes on at least one of the four days. For each species you can identify, report the greatest number of individuals you see at any one time that day. All reporting is done on-line. Go to http://www.birdsource.org/gbbc/. About a third of the Pacific Flyway's migrant waterfowl population winters in the Sacramento Valley, including three million ducks and three-quarters of a million geese. When farmers converted Valley wetlands to cropland last century, migrating waterfowl, squeezed out of their historic range, became a major pest in fall-harvested rice fields. To divert birds away from crops, the government started to build wildlife refuges in the 1930s. Now the 53,000 acres of the Sacramento National Wildlife Refuge Complex provide some of the best winter birdwatching sites in the Valley visit (http:// www.r1.fws.gov/sacnwrc/ or call (530) 934-7774). Surprisingly, however, many rice growers now welcome migratory birds to their fields. With the advent of new short-season rice varieties that are harvested before birds arrive, depredation is much reduced. And now that post-harvest burning of rice stubble is restricted, many growers flood fields during the winter to break down rice straw and control weeds. Migratory birds flock to these flooded fields and forage on the approximately 300 pounds per acre of grain that escapes harvest. Their feeding churns the soil, hastening straw decomposition. Although not yet quantified, feeding by the birds is believed to help with weed and pest control, as well. Dusky-footed woodrats give birth to litters of one to four young during winter and spring. Until they are weaned at three weeks, baby woodrats keep their mouths clamped tightly around their mother's teats when she's in the nest. That way, if mom needs to make an emergency exit, she drags the little ones with her. The ranges of California's four woodrat species virtually blanket the state. These gentle rodents build large, conical nests of sticks, leaves, paper, and any other debris they can pull across the ground. Beneath the sticks, woodrats construct separate chambers for living, rearing young, storage, and waste. Succeeding generations of woodrats keep adding to their quarters, which can grow to eight feet in diameter and the height of a man. If you've never seen one of these nests, you haven't been looking. Next time you're in the hills or woods, peer into the brush and blackberry patches or around the bases of lightning-hollowed trees for these messy piles of sticks and twigs. Grab your binoculars and head to high bluffs that jut into the ocean anywhere along Highway 1 this month to look for gray whales migrating back north to their summer feeding grounds off the Alaska coast. Newly pregnant females are the first to leave Baja California's winter breeding and calving waters. They're followed by mothers with calves, who are apt to swim closer to shore to avoid predators. At Point Reyes National Seashore, the lighthouse and Chimney Rock are usually the best viewing areas. Call the lighthouse to find out whether the coast is clear (of fog, that is) (415) 669-1534.
Liese Greensfelder writes about science and the environment from her home on San Juan Ridge inNevada County, California. |