Butterfly swarm shows up on Denver radar system
6 October 2017
A colourful, shimmering spectacle detected by weather radar over the US state of Colorado has been identified as swarms of migrating butterflies.
Scientists at the National Weather Service (NWS) first mistook the orange radar blob for birds and had asked the public to help identifying the species.
http://www.bbc.com/news/world-us-canada-41528521
