Radar spots trillions of unseen insects migrating above us | Science | AAAS
▻http://www.sciencemag.org/news/2016/12/radar-spots-trillions-unseen-insects-migrating-above-us
Birds and human vacationers aren’t the only creatures that take to the skies each year to migrate north or south. An analysis of a decade’s worth of data from radars specifically designed to track airborne insects has revealed unseen hordes crossing parts of the southern United Kingdom—2 trillion to 5 trillion insects each year, amounting to several thousand tons of biomass, that may travel up to hundreds of kilometers a day.
The numbers, reported in this week’s issue of Science, are “stunning,” says Silke Bauer, an ecologist at the Swiss Ornithological Institute in Sempach. “Wow,” adds Larry Stevens, an evolutionary ecologist at the Museum of Northern Arizona in Flagstaff. “C_an you image what these numbers look like in tropical settings, say, over the basins of the Amazon or the Congo?”
Although some insect migrations are well known (think monarchs), the new work takes a systematic approach to flying insects and hints that such mass movements are surprisingly common. These airborne invertebrates, their bodies packed full of nitrogen and phosphorus, could move significant amounts of key nutrients across the globe. “_Insects are little creatures, but collectively they can have a big impact; comparable in magnitude to large ocean migrations [of plankton],” says Lael Parrott, an environmental geographer at the University of British Columbia in Kelowna, Canada.
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That insects “have an idea of where they want to go to, when they want to go, and what winds are good [is] surprising for these tiny creatures,” Bauer says.