5 Simple Steps for Predicting Bird Migration

With spring rapidly accelerating, now is the ideal time for a little spring migration review. But rather than focusing solely on identification, let’s look over some of what we know about migration itself, specifically its timing, its interaction with weather, and how to predict it. Being able to predict migration—of course within a margin of error—can amplify everything that makes spring migration exciting. Indeed, merely by visiting a few websites, you have the godlike power of knowing when to expect arrivals, influxes, and fallouts, and when the best time to get out there may be.

To get you started, here are five simple steps to help you become your own migration-forecasting guru:

Step #1 – Know what the atmosphere’s doing

For this, I use Intellicast’s Mixed Surface Analysis, which provides two handy pieces of information: 1) Where the frontal boundaries (fronts) and centers of air masses are, and 2) Where precipitation is happening. The atmosphere is composed of air masses, which can be rising, falling, warm and wet, cold and dry, and anything in between. These characteristics interact to make them behave either as low pressure systems or high pressure systems. Here’s the key thing to remember: low pressure systems rotate counterclockwise, while high pressure systems rotate clockwise. This means that when there’s a big “H” on the map, a high pressure center, the air is moving clockwise around it. The opposite is true for the big “L’s” on the map, low pressure centers around which air moves counterclockwise. This allows you to predict where winds will be favorable or unfavorable for migration before you’ve even checked the winds.

Mixed Surface Analysis

Mixed Surface Analysis

Having the fronts depicted brings another benefit: many migrants move ahead of or just behind fronts—if they’re going the right direction. Migrants seem to have a particular affinity for cold fronts, which tend to move faster. But if a front—and the precipitation it carries—is moving the opposite direction of migrants, they can cause migratory fallouts. Either way, keeping an eye on fronts can help you spot those critical moments when your favorite migrant traps will be the busiest with birds.

Step #2 – Focus on the winds

After you’ve ‘read’ the surface analysis map, take a look at a earth map only depicting wind. This is mostly to check your interpretation of the surface analysis map. Are the winds going the direction you predicted? The wind map should make it especially clear where conditions are favorable for migration: anywhere with southerly (from the south) winds has potential to facilitate spring movement. Tailwinds—southerly in the spring and northerly in the fall—are the name of the game, though don’t be surprised when there are exceptions! If you’re interested in forecasting migration further ahead of time than the night before, this Intellicast wind forecast is extremely useful.

Global Wind Map

Global Wind Map

Step #3 – Check the radar

Now that you know where to expect migration, and why you’re expecting that migration, is there any migration? NEXRAD radar is exactly what you need to answer this question (Check out a map of the contiguous US or any of the 3-letter stations codes on the National Center for Atmospheric Research real-time weather data map). NEXRAD stations record images from numerous locations around the country, picking up anything made of water in the atmosphere. Most of the time, this just means clouds and storms systems. But because living things are also comprised largely of water, this means that in large enough numbers they show up on radar too. During the spring and fall, this is exactly what happens with birds, which show up as blue and/or green donut shaped forms on the radar. As the blue gets brighter and then goes green through the night, migration is getting heavier. Massive, mostly green orbs on the radar means extremely heavy migration, or, in other words, that you should probably go birding tomorrow morning.

Nexrad Radar Showing Bird Migration

Nexrad Radar Showing Bird Migration

Step #4 – Check eBird and BirdCast for what to expect

While radar tells us that migration is happening, it doesn’t tell us what’s migrating. For this, I use eBird frequency charts to predict which species are arriving and influxing based on what time of year it is. Scrolling through these charts can give you a good idea of which species will be most abundant tomorrow morning, and which species might just be arriving. Even better, these charts are a handy reminder of those species that you might have forgotten to look for. BirdCast, another Cornell Lab of Ornithology project, provides succinct, regional migration forecasts to enrich what you learn from eBird charts. If there’s anywhere online to visit for condensed migration information, BirdCast is the place.

Step #5 – Get out there!

Now that you know how to read a surface analysis map, how to interpret winds, how to track migration using radar, and how to keep track of which species are moving, you have the power to predict migration. You can predict when it’s happening, explain the weather behind why it’s happening, and even name which species should be part of the mix. All that’s left now, of course, is to go apply it in the field!

by Nick Minor

Chicago Audubon Honors IOS and ILYB Members

CAS Award Recipients

Henry Griffin (left); Matthew Cvetas and Josh Engel (right)

On March 25, 2017, Chicago Audubon held its Biennial Environmental Awards Banquet to honor those who have made contributions to conservation, the protection of migratory birds and other wildlife, and have helped to conserve, preserve, and enhance the varied habitats and open spaces of the greater Chicago region.

Recipients included several IOS and Illinois Young Birders (ILYB) members. Congratulations to all!

  • Young Environmentalist: Henry Griffin – Oak Park Bird Walks
  • Service to Chicago Area Birders: Matthew Cvetas and Josh Engel – Leading/advising ILYB
  • Protector of the Environment — Avocation: Bob Fisher – Bird Conservation Network (BCN) and bird monitor
  • Protector of the Environment — Group: Steve and Jill Flexman – Poplar Creek Prairie Stewards

Rare Bird Alert - 15-Apr-2017

Pine Grosbeak by Geoff Williamson

Pine Grosbeak by Geoff Williamson

Anhinga: Massac (South) – On April 15th, Keith Mcmullen reported seeing an ANHINGA over Ft. Massac State Park in Massac County.

Pine Grosbeak: Winnebago (North) – A PINE GROSBEAK was seen at the feeder of Vonnie and Martin Kehoe on April 13th in Rockton, Winnebago County.

Mountain Bluebird: DuPage (North) – A MOUNTAIN BLUEBIRD was discovered at Fermilab in DuPage County on April 7th by Jason Frey, flitting around on tree tops, south of AE Sea, between the yellow gate and shrubby area to the west.

Swallow-tailed Kite: Massac (South) – On April 8th, Keith Mcmullen reported seeing a SWALLOW-TAILED KITE just east of Metropolis in Massac County.

Smith's Longspur Field Trip Report

I had the pleasure of leading an Illinois Ornithological Society field trip for Smith’s Longspurs in McLean County this morning (April 8, 2017). We did manage a flock of seven and another flock of 28 birds — even in flight good enough looks for multiple lifers in the group — always a great feeling.


Continue reading Smith’s Longspur Field Trip Report

Loonapaloonza 2017 Field Trip Report

Twenty-one observers gathered at the Gale Street Restaurant parking lot at 8am on April 1st to have coffee, muffins, and bagels before setting off to explore several of the nearly 200 lakes in Lake and McHenry Counties in search of loons and other waterbirds.

Field Trip Participants

Several close-in observations of Common Loons

Continue reading Loonapaloonza 2017 Field Trip Report

Homage to a Reluctant Mentor

Jennifer Hoffman, Mixed Media Artist and Designer, shares her poem, Homage to a Reluctant Mentor.

He was:

The mist and the fog on North Pond, while herons stood motionless at the waters edge. The wing beats from the flocks of geese and ducks arriving over the platform. The birdsong of warblers in the

Continue reading Homage to a Reluctant Mentor

2016 Listers Corner

The 2016 Listers Corner is now up and available for viewing! From Yard Lists to Big Days, there’s something for every birder.

Highlights, you ask? Here are a few to whet your appetite:

First, the 400 Club has expanded from one birder to three, as both David Johnson and Joel Greenberg attained the

Continue reading 2016 Listers Corner

Rare Bird Alert - 29-Mar-2017

Neotropic Cormorant: Livingston (Central) – Demetri Lafkas photographed a Neotropic Cormorant at the ponds just north of Pontiac, Livingston County on March 29th.

White-winged Dove: Adams (Central) – Phil and Pat Reyburn had a White-winged Dove visit their feeders in Quincy, Adams County on March 28th.

Black-headed Gull: Sangamon (Central) – H. David

Continue reading Rare Bird Alert – 29-Mar-2017

Wintering Raptors of Central Illinois

General Reflections Based on Surveys in McLean and Woodford Counties

In the fall of 2007, Matthew Winks and I created an approximately 50 mile winter raptor survey route that begins an ends at the Fraker Farm abode. This route heads east south of the Mackinaw River past Evergreen Lake to Lake Bloomington where it crosses

Continue reading Wintering Raptors of Central Illinois

IORC Update - 10 March 2017

This update reports the 2017 membership of the Illinois Ornithological Records Committee (IORC), recent changes to the IORC Review List, and IORC’s decision regarding Illinois’s one record of Green Violetear in light of the taxonomic split of that species into Mexican Violetear and Lesser Violetear.

2017 Membership

For 2017, IORC welcomes Walter Marcisz as a

Continue reading IORC Update – 10 March 2017