Every Chirp Is Hitched
Researchers in the U.S., U.K., Australia, and Canada have plotted out the family tree of the world’s nearly 10,0000 known bird species and discovered that birds are evolving at a pace that defies expectations. Their study, "The Global Diversity of Birds In Space and Time”' was published October 31 in the journal Nature. Researchers found that the creation of new bird species has speeded up over the past 50 million years, and that the formation of new species in the higher latitudes rivals that of the species-rich tropics.
The infographic is compelling (click on it to enlarge), and can help in bird-conservation efforts. According to Gavin Thomas of the U.K.’s University of Sheffield, "We can identify where species at greatest risk of extinction are on the tree and ask how much distinct evolutionary history they represent. Some species have many close relatives and represent a small amount of distinct evolutionary history whereas others have few close relatives and their loss would represent the disappearance of vast amounts of evolutionary history that could never be recovered. Environmental change has very likely affected diversification over time. Climate change could be a part of that through its effects on the extent of different types of habitat."
Birds, of course, are as mobile as any animal you’ll find, but that doesn’t mean they are free and clear. As British Columbia’s Simon Fraser University notes, “Unfortunately, birds’ rosy speciation history doesn’t nullify the fact that they can’t outfly their growing human-induced rate of extinction. Researchers estimate that birds have recently been proliferating at a rate of about one new bird species every 700 years. Meanwhile, they estimate birds’ recent human-caused extinction rate to be about 300 times higher.”
Image from University of Sheffield
Reed McManus is a senior editor at Sierra. He has worked on the magazine since Ronald Reagan’s second term. For inspiration, he turns to cartoonist R. Crumb’s Mr. Natural, who famously noted: “Twas ever thus.”