THE NATURAL MOMENT 



UP FRONT 



■< See preceding two pages 



Precisely because they are full of 

 pitfalls, swamps offer splendid 

 refuge to those adept at sidestepping 

 sinkholes. For dragonflies and other 

 insects, a watery pit makes a good 

 breeding site, and a thin skin of 

 marshy soil makes for an easy land- 

 ing pad. Still, not every surface is 

 safe. The Eastern pondhawk dragon- 

 fly (Erythemis simplidcollis), pictured 

 here, fell prey to another peril of 

 swamp life: the trap set by an insec- 

 tivorous sundew plant. 



The Green Swamp Preserve, near 

 Bolivia, North Carolina, sprawls 

 across some 16,000 acres of shrub- 

 by bog land surrounded by pine 

 savannas. That unusual ecosystem 

 boasts at least fourteen species of 

 plants that feast on live insects. It 

 may be the most diverse carnivo- 

 rous plant reserve in the world — 

 one reason Jack Dermid, a photog- 

 rapher and self-proclaimed outdoor 

 wanderer, regularly hikes there. 



Dermid was on the fringe of the 

 swamp one late-summer afternoon 

 when he noticed a resting dragon- 

 fly. On closer inspection he real- 

 ized a spatulate-leaf sundew (Drosera 

 intermedia) had the hapless insect 

 ensnared in its sticky tentacles — 

 tied down as securely as Gulliver 

 was by the Lilliputians. The sun- 

 dew was already draining the juicy 

 carcass of its nitrogen supply. 



Was the pondhawk new to the 

 hazards of Green Swamp? Perhaps. 

 Recent research shows that dragon- 

 flies migrate great distances — as 

 far as ninety-three miles in a day. 

 Whether visitor or denizen, though, 

 this one didn't make it out of the 

 labyrinth alive. — Erin Espelie 



Life Support 



Quick — name an important mammal of the African savanna. If 

 you're like me, you probably thought of the lion, the cheetah, 

 the hyena, or any of several other toothy carnivores. But sup- 

 porting many of those impressive creatures is the herbivore known as 

 the gnu — or, more formally, the wildebeest. So when Richard D. 

 Estes approached us about contributing an article to Natural History 

 ("Wildebeests of the Serengeti," page 28), we became as excited as 

 crocodiles hiding in a wildebeest watering hole. Estes is perhaps the 

 world's leading expert on the wildebeest, one of Africa's signature large 

 mammals, and no one is better suited to bringing all of us up to date 

 on the gnus from the Serengeti. 



So important is the wildebeest to the ecological health of the African 

 savanna that biologists label it a "keystone" species. And for their part, 

 wildebeests have adapted marvelously well to their role as Africa's hot 

 meal on the hoof. Vast herds of them remain constantly on the go. 

 Some 80 percent of the females manage to give birth within just a few 

 weeks, ensuring that though some of the calves will become hyena fod- 

 der, plenty of others will survive to reproduce another day. The calving 

 strategy also keeps the food glut brief enough to prevent a permanent 

 expansion of predators. Precocious "gnuborns" fit right into the herd's 

 strategy of moving on: they struggle to their feet, on average, within 

 seven minutes after birth, ready for the dusty trail. 



• • • 



From our perspective as creatures living at the bottom of the atmo- 

 sphere, the high mountains seem one of the most inhospitable 

 places on earth. The air is thin, the sunlight burns, the wind howls, and 

 the weather is unpredictable. Most of us are amazed when we discover, 

 say, a wildflower growing in a crevice on a steep boulder field above 

 12,000 feet. It's a natural response, but by now it ought to be recognized 

 as a parochial one. "Extremophiles" — the very name reflects our 

 provincialism — live everywhere: in the superheated water and hydrogen 

 sulfide issuing from deep-sea vents, in caves isolated from sunlight for 

 millions of years, between layers of sea ice floating in the Arctic Ocean. 



Yet until recently, even professional biologists had fallen into the 

 anthropocentric trap of assuming the alpine zone is a sparse and 

 barren land. Writer Kevin Krajick and photographer Carsten Peter 

 ("Living the High Life," page 44) endured pounding headaches and 

 worse at 17,000 feet in order to accompany a biological expedition 

 whose goal was to prove the reverse. And sure enough, the slopes of 

 the high Andes turned out to be home to a surprising diversity of 

 life. Expedition members made so many new discoveries that their 

 simple, factual descriptions sounded, unintentionally, like comic 

 repetition: "the world's highest frog," "the world's highest worm," 

 "the world's highest clam," "the world's highest leech." In fact, the 

 superlatives reflected a lack of prior scientific attention as much as 

 the expedition's own good luck. Making new discoveries in the 

 mountains is easy, explained the expedition's chief scientist, Stephan 

 R.P Halloy, "because we are looking here." 



— Peter Brown 



6 



NATURAL HISTORY September 2006 



