Thursday, April 11, 2013

Making the Most of Bird Migration

In this post I share some awesome websites that I have come across over the past week or so.  The first, Birding by Radar, has to do with the national weather radar:  Watch as strange circles of blue and green eplode outward from dozens of points across the country.

Incedentally, these many of these circles are centered around the nation's most well-known migration hotspots—indeed, these radar images depict the large nightly flights of migratory birds on their way north or, in the fall, south.  For instance, take a look at the radar composites of good migration nights and other similar nights.  If you know where to look, you might see that the evening flights of the migrants are centered around places like Central Park in New York City, High Island in Texas, Cape May in New Jersey, Magee Marsh in Ohio, southeast Arizona, and many other migration hotspots.

In such spectacular flights as the one that occured on the night of May 12, 2011, you can even see flights centered on some of the more local hotspots that you are familiar with.  Looking at the migration that happened that night, I can see a sizeable circle whose epicenter is what I presume to be Kalamazoo Nature Center and/or other nearby migration hotspots.  Earlier in the season, I swear I can see a migration of what are probably enormous flocks of waterfowl leaving one of my favorite birding spots, Maple River State Game Area.

Another interesting thing to watch is the ways in which weather systems affect bird migration.  Take last night's (April 10th) migration.  There is a large storm system moving north and then East across the eastern US.  When the evening flight occurs, all of the major flights happen south of the system, while virtually no flights of any significance occur north of it.  Looking at these radar composites are a tremendous help in deciding whether or not to go out birding tomorrow morning.  If there is a big migration one night, you can almost always depend on there being plenty of birds out the next day.

The second website features an incredible map of current wind speeds and directions.  In spring, winds coming from southerly directions, often indicate that large numbers of migratory birds will drop out of the sky into local parks and woodlots overnight, especially as .  In fall the opposite is true—winds from a northerly direction often signal large numbers of southbound migrants the next morning.

Occasionally, weather like this conjures up the sort of event that every birder lives for—a fallout (more specifically a migration fallout, NOT to be confused with a nuclear fallout—this confusion occurs all too often between birders and non-birders).  Fallouts are the sources of birding legend.  Warblers drip from the trees and carpet people's lawns and rooftops.  20+ species of warblers, tanagers and vireos can be seen in a single shrub.  Because fallouts usually occur before or after a flight of birds completes a marathon journey across a body of water or other area devoid of perching or feeding areas,  hundreds of tiny hummingbirds and exhausted songbirds approach within feet or even inches of one's face.  Places famed for their spectacular fallouts include the previously mentioned High Island, Cape May, and Magee Marsh as well as Ontario's Point Pelee and Michigan's Whitefish Point.

Some other helpful websites include:

Radar and Migration FAQ
Clemson University Radar Ornithology Lab
North Woods BIRDAR--an amazing resource for birders in Michigan!!


  1. Great post Nathan. It's nice to have all these resources linked within one post!

  2. This is really interesting. I would never have thought that the flocks of birds were so large that they would show up on radar. Great job.