Earth Almanac: July/September 2002

Mini Tuna

Little tunny, a.k.a. false albacore and fat Alberts, patrol tropical and subtropical waters on both sides of the Atlantic. But when ocean temperatures peak in late summer, they stream north as far as Maine and Great Britain in shimmering, elliptical shoals that can cover two miles on the long axis. Most people, even experienced anglers, think they're bluefish or striped bass. Watch for the sickle tails and geysers of spray as these mini tunas swill anchovies and other baitfish. Often the school is attended by a cloud of screaming terns and gulls that dip and dive for leftovers. Few of these short-lived, fast-growing fish weigh more than 15 pounds, but when they take your fly, they'll have 50 yards of line off the reel before you can snatch your bruised knuckles from the spinning handle. 

Charlotte's Children

One morning in early fall, your lawn may be draped with a silver fabric bright enough to mimic a pond's surface but so fine it seems to have no mass. Chaucer called the phenomenon one of the unsolved mysteries of the universe. Subsequent investigators attributed it to evaporated dew. It took a pig to pin it down: "The baby spiders felt the warm updraft. One spider climbed to the top of the fence. Then it did something that came as a great surprise to Wilbur. The spider stood on its head, pointed its spinnerets in the air, and let loose a cloud of fine silk. The silk formed a balloon. As Wilbur watched, the spider let go of the fence and rose into the air." That passage, from E. B. White's Charlotte's Web, remains one of the best descriptions of how many juvenile North American spiders disperse. Darwin observed silk-riding spiderlings when the Beagle was 60 miles from land. In May 1884, 10 months after the most powerful volcanic explosion in recorded history sterilized the island of Krakatoa, the first scientist to set foot on the site found only one life-form: a spiderling. Census traps mounted on airplanes have caught spiderlings at 15,000 feet. Occasionally, they'll ascend to the jet stream and cross the Atlantic. 

Bully for Bullwinkle

From the Rockies east, moose, earth's largest deer, are filtering south as the species gradually rebounds from the unregulated hunting of the 19th century. In New England, moose are even colonizing suburbia; recently they've been encountered in southern Connecticut. If you have seen heart-shaped tracks too big to be white-tailed deer, listen for the vocalizations of rutting bulls—moans, whines, and a series of grunts that, while not loud, are so deep that they carry long distances. Moose, which are at the southern fringe of their range in the contiguous United States and therefore don't need the thermal cover that deer require, are benefiting from clear-cutting. The practice encourages nutritious leafy growth and, at least in the north woods, it destroys deer habitat. This, too, is beneficial for moose, because deer are commonly infested with a brainworm, which they carry with apparent impunity. But when the same brainworm infests moose, it blinds, maddens, and eventually kills them. There are now so many moose in Maine, Vermont, and New Hampshire that these states have reinstated hunting seasons. In Maine, 85 percent of the hunters who drew permits in the 2001 "moose lottery" killed a moose. Despite the moose-hunting tip offered by waggish critics—"Take 10 steps back and shoot"—the resource is being superbly managed.