The image has been captured and shared widely on social media – a sign of the annual southward migration of millions of birds that is in full swing across Canada as the arrival of shorter days and cooler temperatures signals them to fly in search of sunnier weather. the south. The phenomenon is called “bird ring”. The US National Weather Service describes it as “when the radar beam detects thousands of birds taking off from their roosts around dawn to forage for insects.” The image was posted on social media by meteorologist Corey Elder, who told CBC News via email that while it’s common to see rings, it’s rare to see “such a perfect concentric ring.” The perfect deposit sounds far away this morning! pic.twitter.com/zdGveUSTYW —@coreywxelder Although most people have never seen it, professional weather watchers see it quite often, according to Jim Mitchell, a National Oceanic and Atmospheric Administration (NOAA) meteorologist across Lake Erie in Buffalo who works at radar station that captured the image. .
Long Point is a UNESCO Biosphere Reserve
“The birds are all perched together, and obviously when they take off, they have to spread out. It looks like a ring when they fly away, and there are so many of them, it seems,” Mitchell said. Mitchell said the radar station in Buffalo is so sensitive, it picks up cars on the nearby freeway and flocks of seagulls scavenging piles of trash at a landfill south of the city. But the size and scale of the flocks of birds in Long Point are so massive and dense, they show up on radar even though Buffalo is 100 miles away, he said. “Long Point, this is the most intense we see.” It’s because Long Point is the largest freshwater sand spit in the world and one of the most important areas for migratory birds in North America. Swallows like this are believed to be among the birds that form the rooster ring in the sky at Long Point. (David M. Bell/Macaulay Library at Cornell Lab of Ornithology) This sandy, narrow and uninhabited peninsula stretches 40 kilometers into Lake Erie. It is so unique and rich in endangered species that it has been recognized as a UNESCO World Biosphere Reserve. “Together, it’s probably the largest wetland, if not the largest wetland, in the entire Great Lakes,” Stewart McKenzie said. As director of strategic assets for the non-profit Birds Canada, it’s his job to manage the Long Point Bird Observatory and the field work that goes on there.
The flock is likely swallows or purple martins
McKenzie said that, given the size of the ring and the time of year, it’s likely that barn swallows, barn swallows or purple martins, or a combination, were the birds swarming in the hundreds of thousands, roosting, laying eggs and they grew fat. the trip to abundant insects. Male purple martins have an iridescent purple color all over. (Image courtesy of Jonathan Kells) “Why it’s so attractive to swallows is because of these protected wetlands; it gives them a safe place to rest at night and huge amounts of food to forage during the day.” The flock is likely from most of southern Ontario, perhaps even farther, and the birds are gathering at Long Point to roost at night, McKenzie said. At dawn, they leave in such large numbers that radar stations can detect them at a distance of more than 100 kilometers. “The low end, in terms of rooster size, is about a hundred thousand swallows every night and, at the high end, it’s well north of half a million. “On the radar, it gives this kind of donut signature, with the center of that donut being the location of the bearing as the birds disperse from the site in all directions,” McKenzie said. He said the phenomenon happens for a few weeks, and then one day, the birds decide to leave and fly to the southern United States or South America for the winter. Before they go, however, McKenzie said, being there on the ground and watching the birds congregate yourself is a sight to behold. “It happens very close to sunset when they start rooting. They start swarming and mixing and spend about half an hour or 45 minutes wandering around the wetlands moving in these big swarms. “It’s almost like a tornado or an eddy. These flocks go around and around and around, and then that eddy goes down into the marsh, and then the birds peel off,” McKenzie said. When we didn’t have this technology, they probably turned off the radar. It’s hard to say.- Stuart McKenzie, Birds Canada “They seem to be in this coordinated fashion, and eventually they will go down into the wetlands and disappear.” It’s something birds have been doing for thousands of years, and yet only relatively recently have we had the technology to see it on a large scale at Long Point and similar sites, such as Walpole Island or less often at Point Pelee. “For me, it’s a humbling experience,” McKenzie said of seeing birds whose populations have declined by 50 percent in the past 40 years gather in the hundreds of thousands. “There are half a million now. It’s amazing. What was it like 50 years ago? When we didn’t have this technology, they probably turned off the radar. It’s hard to say.”
