Science Snippet: Bird Brained

Motorized vehicles kill around 250 million birds a year. A French evolutionary biologist theorized that, more often than not, it is birds with smaller brains that meet their end on the grill or under the tires of a car or truck. He figured that birds with larger brains were smarter and might have the intelligence to dodge such a fate, but he couldn’t figure out how to prove this theory. However, 30 years later he learned about a taxidermist who had carefully examined 3,521 dead birds (of 253 different species) in an effort to determine cause of death. Further, he removed and weighed the bird’s internal organs, including the liver and brain, and duly recorded the weights in his logbook. The biologist heard about the taxidermist and the two of them got together to try to make something of all the data the latter collected. They compared weights of organs from birds killed by traffic with organs from birds that died from “natural causes.” They found no difference, with one exception—among birds with larger brains death by traffic was unheard of. They concluded that birds with larger brains were smart enough to avoid becoming roadkill. (Moller and Erritzoe, 2017, “Brain size in birds is related to traffic,” in Royal Society Open Science, Mar. 29 issue; The Economist, April 1, 2017)

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