Earth Almanac

Earth Almanac

Cold-weather moths; desert wise guy; midwinter's sweet treat; blizzard-loving bison; bicoastal, beach-storming dunlins; more.

By Ted Williams
Published: January-February 2012

1 | Blizzard-Proof Bovines

Northern winter is hard on all wildlife, but you'd never guess it from watching American bison. When they migrate it's not far--usually just to lower elevations. Blasted by blizzards, they face into the wind, scenting grass through the drifts and using their massive heads as snowplows. So well insulated are they that snow accumulates on their thick, shaggy coats without melting. Before European settlement, bison range extended from Mexico into Canada and from the Atlantic nearly to the Pacific. North America almost lost them twice--when they barely survived the massive extinctions that doomed other ice age megafauna, and in the 19th century, when they were reduced from perhaps as many as 65 million to fewer than 1,000 by market hunting and eradication aimed at subduing hostile Indian tribes. There are two subspecies: the more ubiquitous plains bison and the larger, higher-humped woods bison. Today both persist in the wild but only in a shadow of their natural habitat.

2 | Magic Moths

Anyone can find magic on midsummer nights, but you have to look hard for it in the depths of winter. Those moths caught in the glow of the Hunger Moon (some with eyespots on their wings, presumably to scare off predators) did not issue from your attic clothes closet. They are owlet moths. The family, represented worldwide, includes 35,000 known species. "The classification [of the family] rests in a state of great confusion, and few authors appear to hold similar views," wrote one researcher, who went on to confess he'd "wasted time" in the hopeless task of trying to sort out the taxonomy. When temperatures dip below freezing owlet moths hide under leaves and snow. Otherwise they rev up for flight by rapidly flexing wing muscles, thereby increasing their body temperature from near freezing to as high as 86 degrees Fahrenheit. In the air thick scales help them retain heat. Evoking a bit of owlet-moth magic are some of the species' names, which include night-wandering dagger, festive midget, toadflax brocade, asteroid, scribbled sallow, confused woodgrain, German cousin, thoughtful apamea, ignorant apamea, and delightful bird-dropping--whose appearance is anything but "delightful." In fact, it looks like, well, scat.

3 | Outdoor Carpet

It looks warm and comfortable, as if earth and rocks were cloaked in shaggy gray bathroom carpet that would let you stroll barefoot to the outhouse. But this is tundra and boreal forest, and you might have frostbitten toes before you got there. The "carpet" is caribou moss, not really a moss but a lichen--a symbiotic union of algae and fungi, the former providing nutrients and the latter, housing. While most species occur in the circumpolar Arctic and sub-Arctic, they've been reported in alpine and wind-swept habitat as far south as Tennessee. Among the few creatures capable of digesting caribou moss are caribou--which apparently evolved to take advantage of this vast and nutritious food source--southern red-backed voles, and humans. The Dena'ina natives of Alaska boil it until it softens, and Scandinavians render it to powder for thickening soups and desserts. But eating caribou moss can be dangerous for both humans and wildlife. It's such a sponge for heavy metals and sulfur oxides that it has been used to monitor air pollution. And in the days of atmospheric nuclear testing, Alaskan natives whose diet included caribou were found to harbor high levels of Strontium 90.

4 | Desert Sass

Rare is the birder who has not been thoroughly bawled out by a jenny wren. Triple that and you get the sass and volume of the cactus wren, the largest wren in North America. Now, in desert thickets of California, southern Nevada, Arizona, New Mexico, Utah, west Texas, and northern Mexico, they're courting or nesting. The male, shouting at you from the top of that saguaro, makes it clear he doesn't approve of you, your dog, or the horse you rode in on. (To hear and see him, click here.) In the protection of cactus thorns, a mated pair builds a nest of plant materials the size and shape of a football and with a side entrance. Then the male builds a roosting nest for the female. Cactus wrens forage mostly on the ground, gleaning water from the seeds and cactus fruits they consume. Few birds are as inquisitive. Leave your car windows open and one is apt to hop in and check out the interior, giving you the feeling you should have hidden your keys.

5 | Iced Apple

Most other forest fruit is long gone, but now, when winter-stressed creatures need it most, fireberry hawthorn serves up its sweet red or pinkish-orange mini apples. From Newfoundland to Pennsylvania and west to the Rockies, some of the more avid consumers include deer, bears, small rodents, ruffed grouse, fox sparrows, robins, cedar waxwings, western and eastern bluebirds, and people (who eat them raw or incorporate them into pies and preserves). Few plants are more tolerant of wind or cold, a hardiness that makes fireberry hawthorn especially useful for shelterbelts and erosion control. And its fruit, along with the cover it provides with its many long thorns, will attract wildlife to your yard while simultaneously beautifying it. "Many are the allusions to the hawthorns of England in poetry and prose," wrote 19th and early 20th century botanist Eloise Butler. "It is pertinent to ask why writers neglect to extol the American species. For our hawthorn trees or shrubs are of extreme beauty, when covered with their snowy fleece of bloom, or when glowing with the sweet tasting, stony bright red 'thorn apples.'"

6 | Winter Flings

Beaches and tidal flats from southern Alaska and Massachusetts to Mexico can get crowded with people and dogs in spring, summer, and fall. But at least in the northern part of this range, when spindrift freezes in the air and one has to lean into the chapping sea wind to make forward progress, you can somehow find solitude. Gone are the shoals of predator fish and the screaming gulls and terns that hovered over them. The scene is far from lifeless, though. Enormous flocks of medium-size sandpipers called dunlins (from the Anglo-Saxon "dunn," for dark brown) forage for worms, mollusks, and crustaceans, stabbing the sand and mud methodically and rapidly with stout, down-curved bills--a feeding behavior that has given the species its alternate name of "sewing machine." Watch these birds in flight as the tight flock, called a "fling," moves in synchrony, each turn rippling through it as if it were a kite tail in the wind. Researchers believe this is learned behavior that unschooled juveniles can't master, which makes them particularly vulnerable to falcon predation. Flings made dunlins easy quarry for shotgunners during market-hunting days, when their populations were greatly reduced.

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Ted Williams

Ted Williams is freelance writer.

Type: Author | From: Audubon Magazine