What You Can See on Feb. 18
Submitted by Ted Williams on Sat, 02/18/2006 - 10:09.
From Audubon’s Earth Almanac by Ted Williams and compiled in “Wild Moments,” edited by Connie Isbell, Illustrations by John Burgoyne, Storey Publishing, 174 pages. Frozen Fliers By aquatic insect standards the life cycles of the roughly 600 species of stoneflies inhabiting North America are normal enough. But one family -- t he Capniidae, or winter stoneflies -- live in reverse. When frigid weather sends virtually all other flying insects to death, dormancy, or southern latitudes, the nymphs of winter stoneflies crawl from under submerged stones, make their way up streambanks, anchor themselves to rocks with gluelike secretions, pull themselves out of their larval skins, and take to the chilled air as four-winged adults. Winter stoneflies are no accident of nature; they enter a world virtually devoid of bird and insect predators. Look for them on streamside snow and ice or lumbering along in slow flight like giant gray mosquitoes. Unlike most insect infestations, an infestation of stoneflies -- encountered at any season -- gladdens those who delight in undefiled habitats. When water-quality surveyors turn up stoneflies in their macroinvertebrate samples, they classify the stream as "good quality" because these insects require clean, well-oxygenated water. Fishlight In the "dead" of winter, Pacific Northwest rivers come alive. From Monterey Bay in California to the Pribilof Islands in the Bering Sea, candlefish, a species of smelt, sweep in from the rich Pacific, staging in vast, shimmering shoals at river mouths before they start their short spawning run to low-elevation tributaries. Now all manner of life forms converge to swill this protein in spectacular orgies -- harbor seals, sea lions, cormorants, mergansers, loons, grebes, bears, eagles, beluga whales, and humans. So rich in oil are the fish that settlers used to insert strips of bark in the dried body cavities and burn them as candles. Indians would fill canoes with candlefish, let them ferment for two weeks, then add water, heat it with hot stones, and skim off the clear oil, prized for seasoning and preserving.