NEBRASKAland Magazine is dedicated to outstanding photography and informative writing with an engaging mix of articles and photos highlighting Nebraska’s outdoor activities, parklands, wildlife, history and people.
Issue link: http://mag.outdoornebraska.gov/i/963498
12 NEBRASKAland • APRIL 2018 By Joel G. Jorgensen Not long ago the only way most people could view Doppler weather radar was to tune into the weather segment of a local television news broadcast. Smart phones, tablets, computers and the internet have changed our ability to access all sorts of information, and now real-time Doppler radar can be viewed at any time of day or night, even when there are no clouds in the sky and no chance of rain, snow or thunderstorms in the forecast. Increased accessibility of this technology can now be put to an unexpected use – tracking migrating birds. During spring and fall, millions of birds travel between their wintering haunts to our south and breeding sites in our area and points farther north. All species undertake strategies to fly from point A to point B that help them minimize risk of predation and over-expenditure of valuable energy reserves. Some species migrate during the day, but many others, including most songbirds, migrate during the nighttime. The vast number of migrating birds that take flight shortly after sundown during spring and fall migration can be easily seen on Doppler radar, and it is possible to watch the movements of migrating birds on time loops of radar images. The radar signature of birds is distinctive in terms of height and speed of movement and flocks light up radar as concentric rings around radar installations when conditions are favorable, such as south winds during spring and north winds during fall. Migrating birds land before sunrise and, consequently, the activity on radar dissipates before dawn. Radar is frequently used by researchers to address questions about migrating birds and bats. Birders now regularly access radar during migration season to get a sense of whether there will be an influx of migrant birds in the area and whether it makes sense to set the alarm clock early and head out to a favorite birding spot before dawn. Radar can be used to show patterns of bird migration at regional scales and is frequently used to monitor passage of birds over the Great Lakes and Gulf of Mexico. The signature of migrating birds may only be strong on one side of a weather front since conditions on the other side may not be conducive for migration. In the coming weeks, especially during early to mid- May, you can observe the mass migration of birds by visiting a website, such as the National Weather Service (radar.weather.gov/conus/uppermissvly.php), which provides access to Doppler radar. Observe the radar loop immediately before and after sunset when there are south winds or when the weather is relatively calm. Radar returns that appear shortly after sunset almost certainly will be migrating birds representing dozens of species. ■ Regional Doppler radar before and after sundown on May 13, 2017. The top image captured at 8:37 p.m. shows a calm and quiet evening, while the second image captured at 9:55 p.m. has "lit up" showing a lot of activity which represents migrating birds. Observing Migrating Birds by Watching Weather Radar