The Best Tools for Forecasting Bird Movements and Migrations

Birders don鈥檛 have crystal balls. But we do have the internet.

If birders could have a superpower (specifically for birding), I bet most would wish to see into the future. We鈥檙e always trying to figure out the best places and times to bird. Which day is that big migration going to make landfall? Will the birds be hanging out in the woods or at the lake? Should I on Wednesday or Thursday? It鈥檚 important foresight. I don鈥檛 know anyone who鈥檚 gone so far to but I鈥檓 not saying it鈥檚 a bad idea, either.

Or maybe, birders can just use the internet, which now contains a bounty of sources to help them figure out where they need to be when the birds coast into town. Here are the ones I鈥檝e found to be the most useful.

eBird. Back in prehistoric birding times, you needed to know the right people to get precise local histories, or work to write them yourself. Forecasts were based on seasonal arrival dates, built up and honed over years of observation鈥攁lmanac-style. Birders in Washington D.C. knew to start looking for Yellow Warblers around the third week in April, say, because that鈥檚 when Yellow Warblers always show up.

But now, eBird makes it a whole lot easier. Just a few clicks around the website's 鈥鈥 tab can reveal all kinds of information about when to expect certain species. Clicking on the 鈥淎rrivals and Departures鈥 link from there will give you , sortable by state, county, hotspot, observer . . . you name it. I鈥檝e found that the species-specific graphs found through the 鈥淏ar Charts鈥 selection on same page are equally useful. Clicking from there on a particular species will also get you a lovely little line graph that marks when a bird arrives, peaks, and moves out. (Turns out the third week in April was a pretty strong bet in D.C.)

BirdCast. While eBird鈥檚 online features are great for showing you annual patterns, they don鈥檛 let you know exactly how well this year鈥檚 migration is panning out. For that level of analysis, from the Cornell Lab of Ornithology is a one-stop shop. BirdCast uses weather reports, radar, machine learning, and a 鈥渃ompletely automated pipeline of algorithms鈥 (whatever that means) to produce region-specific forecasts of bird movements a week in advance.

Unlocking the goods is easy. Simply go to your to scope out dozens of migratory species and their arrival dates, which ones are peaking, and which ones will be departing from your area in the coming weeks. The forecasts also reveal how noticeable the migration will be, which in turn, tells you how easy-to-find the birds will be. Even better, BirdCast lets you know the length of the migration window for each species. Each region is fairy large, but the site does a solid job of explaining how the weather will affect migration on a more local level. Honestly, with BirdCast, all you really need to do is remember to bring your binoculars.

Winter Finch Forecast. Ontario ornithologist Ron Pittaway is birding鈥檚 Nostradamus鈥攅xcept that Pittaway鈥檚 predictions actually come true. He focuses his expert skills on passerines that journey between the northern boreal forests and the Eastern United States: Red and White-winged Crossbills, Evening and Pine Grosbeaks, Common Redpolls, and other species that most American birders rarely see outside of the Rocky Mountains. Some winters, though, these species can be found far south of their typical range. Pittaway knows why and when.

It鈥檚 simple, really: Birds will travel epic distances to find food. To make his highly educated guesses, Pittaway studies the chow these birds need to survive the winter鈥嗏攕pruce cones, mountain-ash berries, and others鈥攁nd determines whether there will be a big winter crop or not. A rich crop means that the birds won鈥檛 need to go far to eat, but a down year means they may fly well south, into the waiting binoculars of U.S. birders. Pittaway puts his findings online, and this reports a bumper crop of food across eastern Canada. So most of us down here will just have to wait until next year for any irruptions.  

Weather Radar. If you want to take the next step and craft your own predictions, think about watching radar. As large masses of birds (and and ) take off into the air to begin the evening鈥檚 migratory movement, they interact with the pulses of electromagnetic energy shot out by weather stations to identify clouds and rain. Those masses of animals can then be seen on maps as a growing circular blob, or, more eloquently, a 鈥渂loom,鈥 around the radar base.

The keen birder can then 鈥渞ead鈥 the bloom, interpreting the patterns, speed, direction, and other data to get a sense of how many migrants might be on their way that night. Combine that information with larger weather patterns (for example, any fronts in the area that may ground large flights) or geographic features (migrating birds almost always stop near the coast) and you can get an idea of how productive the birding might be the next morning. The has some great nightly images to get you started; but you can also  for plenty of tip offs when good migrations are getting underway.