“I don’t think we realized what we The cod and cricket example (yes, were getting into,” Gillooly says. The Ophir says, a cod makes a sound like a result was a mountain of information low “errrrrrrrr”) is just one of many that Ophir and his counterpart, biologist Jamie “that is arguably the biggest data set that’s ever been analyzed.” Gillooly of the University of Florida, studTo compare a cod to a cricket, they ied by taking the work of other researchdecided to look at body temperature and ers and comparing animal calls — the body size, the two most important deterfrequency, duration, pitch and intensity minants of metabolic rate, says Ophir, — and plotting them against their body who holds a doctoral degree in animal temperature and size, critical components behavior from McMaster University in of their metabolic rate. Hamilton, Ontario, and a bachelor’s It’s the first time in history anyone has linked so many different species’ audible communication to a common general factor. The link is doubly important when one considers scientists have been studying animal calls for centuries. Gillooly and Ophir in January published their investigation in the proceedings of the Royal Society, the United Kingdom’s national science academy. The discovery set the scientific press a-buzz. Articles have appeared in The Scientific American and Science Daily, including one carried by more than 50 other news outlets including YahooNews. com and U.S. News & World Report. The Discovery Channel’s The Daily Planet in Canada also featured it. The two started the study in 2007 when Ophir was doing his postdoctoral work at Florida. Gillooly, an expert in how organisms use and store energy, told Ophir he wanted to look into a possible link between communication and metabolism. Ophir was skeptical but intrigued. He decided to help mainly because he simply wanted to know the answer. Gillooly says he wanted to work with degree in behavioral neuroendocrinology Ophir in part because the professor is a from the University of Texas. gifted scientist with invaluable expertise “When you convert these metabolic in the nerve firings and muscle contracfactors and plot them on a graph, you tions behind organisms’ social actions and find these animals just line up along this activities. Ophir’s research at OSU focuses predicted line more or less exactly,” Ophir on the brain mechanisms behind social says. “So, if you assume all things are behaviors, particularly monogamy among equal, body temperature and size, and prairie voles and the regions of the brain hold the metabolic rate constant, the calls associated with the practice. The scientists began by laboring through semantics, exhaustively figuring out how to classify the calls according to the unique sounds, pulses and syllables that compose each species’ distinctive calls. Then, the two read paper after paper, poring over figures, sonograms and muscle contraction rates.
“So, if you assume all things are equal, body temperature and size, and hold the metabolic rate constant, the calls across all organisms sound the same for the most part.”
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across all organisms sound the same for the most part.” It’s the equivalent of converting each of their 500 species into one species that simply speaks different languages — just like humans. “With all scientists, our purpose is to understand how the world works,” Gillooly says. “Whenever you can understand something across a large diversity of species from insects to whales and birds, it’s really exciting.” The results open up new areas for further study that could lead to new insights into ecology, including the effects of climate change and how natural selection influences communication methods. Ophir says heat has been shown to increase metabolism, and if communication is linked to metabolism as their study indicates, the calls of animals such as fish and reptiles, which rely on the environment to regulate their body temperatures, will become higher than normal as temperatures rise. Because higher pitches travel shorter distances, warmer climates could force animals that rely on their calls for communication to live even closer together in order to interact. That could cause populations to collapse into smaller areas, cramming more into a square mile than before, and potentially lead to resource depletion and issues with food, disease and habitat limitations. All these changes could end up affecting ecology on a global scale, Ophir says. “Who knows what you can do with these research results. With this giant database, we and other scientists can start asking some really interesting questions, such as how does the habitat you choose affect the kinds of calls you make,” Ophir says. “The research potential is just as creative as whoever is studying it wants it to be.” M at t e l l i o t t
Published on Jun 6, 2012