January 29, 2015 | David F. Coppedge

Smart Mammal Tricks

Take any animal group. The closer you look, the more interesting things get. Check out four mammals.

Seal whiskers:  “Wavy facial hair helps seals find food,” Science Magazine reports. It’s not just having whiskers, but having the right shape whiskers, that makes them good probes. Cross-sections of the whiskers of harbor seals are show them to be non-cylindrical. Their “wavy” shape stabilizes them so that they don’t flop around when the seal swims. This way, they become more sensitive to vortices created by nearby fish. This helps explain why you can “Blindfold a harbor seal, clap headphones on its ears, and the keen hunter will still be able to track a distant fish, using its whiskers to detect the ripples made by its prey,” Devin Powell writes.

Gerbil vision:  Humans have a visual ability called “color constancy,” where we know a color despite the lighting conditions or background colors. Now, it turns out that gerbils have this ability, too. Experiments at Germany’s Ludwig Maximilian University, reported by PhysOrg, showed that gerbils correctly identified colors that yielded a food reward when the background colors and brightnesses were altered. This helps the diurnal animals recognize conspecifics all day and in low angle sunlight. “Gerbils are thus the first rodents shown to have the ability of color and brightness constancy,” the report states. “The result suggests that other animals may possess this perceptual ability, too.”

Bear ecology:  Bears help plants by eating ants. This is the conclusion of a study that observed environmental impacts of bears eating one of their favorite snacks: ants.  The surprising result was reported in a Florida University press release. No animal lives in a vacuum, a principle of ecology shows. Ants have a symbiotic relationship with treehoppers, which feed on rabbitbrush. Intrigued by healthier rabbitbrush plants in the vicinity of ant nests disturbed by bears, the biologists determined that the ants protect the treehoppers from other insects. When the protective ants are fewer, the treehoppers get eaten by other insects. Thus, the plants do better. “This study provides a reminder of how interconnected many species are in an ecosystem,” the article says—another reason you shouldn’t feed the bears.

Bat dinner bell:  Bats have a unique signal to their fellows, PhysOrg says. They eavesdrop on other bats who are hunting with sonar. A one-minute NY Times video clip tells the story: researchers at Tel Aviv University attached data recorders to the backs of “greater mouse-tailed bats” and then recovered 40% of the loggers after they fell off. The recordings showed that bat sonar is only effective on prey about 33 feet away, but neighboring bats can hear the hunting calls of their neighbors over 300 feet away. If one bat is getting food, the others come a-flying—somewhat like frat friends rushing to the side of a guy opening a bag of Doritos. Interesting factoid in the article: bats account for 20% of mammal species.

What is it like to be a bat? philosopher Thomas Nagel famously asked in an influential essay refuting reductionism of consciousness. Each species has its own way of experiencing the world. The ecology is a complex web of interactions between very different animals. Studying these animals and their interactions from a design perspective reveals complex equipment from the intracellular level to the phenotypic level to the ecological level. Where’s the joy in saying, “it evolved”? That, we feel, is the science stopper. When you see something working well, you want to know how it works. That brings joy, insight, and motivation to use similar design principles for human good.



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