While having a night’s sleep this week, more than 30 million migratory birds flew over Colorado, nearly five times the number the night before, at an average speed of 28 miles per hour and an average altitude of 1,100 feet. And of those, more than half completely traversed the state en route to their winter quarters.
We know these things and more because of a fascinating website run by a consortium of ornithologists from Colorado State University, the Cornell Lab of Ornithology and the University of Massachusetts-Amherst.
It’s called BirdCast. It uses Doppler radar to detect birds in flight during the migration seasons (autumn and spring) in the same way it tracks where it rains or snows, except meteorologists filter out the radar returns from birds. Radar ornithologists filter out echoes from the weather.
One of BirdCast’s features is a time-lapse map of the United States showing the migration that took place over the previous night, with areas of migration color-coded by intensity as well as the direction the birds were traveling. A line marking the edge of night moves east to west, showing migration exploding across Colorado after nightfall. You can also put Colorado — or even your county — into a feature called Migration Dashboard to get all sorts of data about what happened above you while you were sleeping.
Data feeds are available during the fall migration from August 1st through November. 15 and spring migration from March 1 to June 15.
Kyle Horton, an associate professor at CSU’s Department of Fish, Wildlife and Conservation Biology, leads a 10-strong team of undergraduate, graduate and postdoctoral researchers working on BirdCast.
“We’re doing this for a number of reasons,” Horton said. “A large one works to protect migratory birds and disseminates information to the public. Bird watching is one of the biggest hobbies in the US. When we tell people that millions of birds are migrating, or that “300 million birds were expected to fly over the US last night,” it really gets their attention and excitement. her miracle.”
This is an exciting time of year for bird watchers. Zach Hutchinson, community science coordinator for Audubon Rockies, said every migration season brings hope.
“It keeps things fresh and exciting and new,” Hutchinson said. “It doesn’t matter how many hikes you’ve been through, there’s always a chance you’ll see a new bird — even if I’m just sitting in the office with a bird feeder or two out the window.”
BirdCast is a great tool for birders from veteran to novice. Its mission is part education, part advocacy.
“Often times[the public]gets excited about making a change, like turning off the lights or getting up early to see what’s landed, what’s new in your yard,” Horton said. “Bird migration is full of mysteries. What will show? You ultimately don’t know this answer until you go out and explore a little. It is exciting for us to be able to engage with the public and stakeholders in this role.”
Ornithologists say light pollution poses a significant threat to birds because it causes disorientation and collisions with buildings, while rattling their internal clocks. The slogan for World Migratory Birds Day on October 9th is “Dim the Lights for Birds at Night”.
“When it comes to light pollution, we have a quick and easy fix,” Horton said. “We could fix it tonight if you had enough collective will. This is not true for all threats that birds face. If we talk about land conversion or climate change and change those things today, they could take decades to fix. We know what the problem of light pollution is and we know how to fix it – turn off lights, dim lights. That goes very quickly.”
In addition to providing raw numbers of nocturnal bird migrations over a given state or county, BirdCast provides a lot of other fun information. It publishes a daily line chart showing the hourly number of birds in the migration the night before. For example: Tuesday night’s 30 million peak occurred on Wednesday at 3am. There are line charts showing nightly numbers for the season since August 1st, flight direction, speed and altitude hourly through a specific night and more.
And because some of these migratory songbirds might make a pit stop in your backyard, BirdCast lists birds that are likely to be migrating through Colorado. Each bird on the list is shown on a photo. If you click on the bird you can see more photos along with some facts about this species and its travels.
Most birds migrate at night, Horton said, because of the cooler temperatures, calmer winds and less threat from predators. Colorado is the destination for some, usually those breeding in Alaska and Canada, before wintering here. Birds that have summered here will travel to New Mexico, Mexico and even South America. One of them is the Bobolink.
“It may breed in parts of Colorado but winters in the southern reaches of South America,” Horton said. “They cover thousands of kilometers. Some may fly over the Gulf of Mexico for a day, land in Mexico’s Yucatan Peninsula and venture into Colombia, Brazil and Chile.”
The reason birds migrate is not to escape cold temperatures.
“They can probably handle slightly cooler temperatures,” Horton said. “Mostly they track food resources. Cooler temperatures often result in lower amounts of food for these birds, especially if they eat insects like a bobolink would.”
Hunters crossing Colorado travel from the Arctic Circle en route to South America.
“What’s just amazing,” Hutchinson said, “is to have this connection to a place (the Arctic) that a lot of people might never get to see, but they’ll be able to see a portion of it, possibly flowing through their local pond or lake.” .”
