Wild Things: Life As We Know It
Human behavior, primate intelligence, meal planning, tree-dwelling orchids and detangling history.
- Smithsonian magazine, September 2006, Subscribe
Meal Planning
Meerkats, those sociable mongooses in southern Africa, have a daunting favored dish: scorpions. So how do meerkat pups learn to eat without getting stung? Gradually, according to a new University of Cambridge study. The researchers found that older meerkats first present pups with dead or disarmed prey. Only after the youngsters get the hang of this cuisine do elders introduce live meals complete with stingers. It's well known that, in many species, animals learn by observing their own kind, but this study is among the first to document wild mammals actively teaching youngsters, including unrelated ones.
Dept. Of Surveillance
People tend to be on best behavior when they're being watched. But what if the only eyes staring at them are on paper? In a University of Newcastle lounge where paying for coffee was optional, researchers placed a picture of either flowers or a pair of eyes next to the suggested price list. Visitors donated almost three times more money when the eyes were posted. Apparently, even a 2-D witness was enough to deter some potential coffee-kitty cheapskates.
Detangling History
Two pieces of Spanish amber contain the oldest known spider web (trapped wasp, inset) and orb-weaving spider; both specimens are at least 110 million years old. The new findings, along with an analysis of the proteins in spider silk, indicate that orb-weaving spiders date as far back as 144 million years. That's when flying insects may have evolved ways to elude spiders, like "dust" on butterfly wings, which prevents them from sticking to webs.
Weather Mavens
Researchers from Scotland's University of St. Andrews followed a group of mangabeys in Uganda's Kabale Forest as the animals foraged for figs and the larvae that infest the fruit. Once the animals ate the takings from a particular tree, they returned to the same spot if the sun had shone for several days, making fruit and larvae mature in the heat. But if it had been cool and cloudy, the mangabeys looked elsewhere for lunch. The observation adds to scientists' growing appreciation of primate intelligence, suggesting that mangabeys, not unlike farmers, take the weather into account when deciding what's ripe for picking.
Observed
Name: Holcoglossum amesianum, a tree-dwelling orchid
Innovation: Mateless mating
You Can't Mean: Actually, we can. Other flowering plants pollinate themselves, but only with help from birds, insects, wind, gravity or sticky secretions. H. amesianum is the only plant known to have sex with itself. Its two pollinating organs sit above the stigma, or female organ; the pollinia swing upward on a flexible shaft, then curve down and into the stigma.
Well, Isn't That Self-Centered: It's also necessary, say the Chinese researchers who observed the plant's sex life. The 1,911 specimens they studied in Yunnan Province flowered in the dry season, when there was no wind, no moisture, no bugs and no birds to help out.
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