Bird Migration Update (April 2021)

Spring bird migration season is here!  In Colorado the peak of spring migration is in early May.  Studies show that huge numbers of birds fly on just a few nights.  Colorado State University’s bird migration forecast can predict migration activity levels one, two, or three days in advance.  Watch for alerts at, and see how many birds are forecast to be migrating on any given night. 

The bird migration “alerts” forecast relatively high migration activity on a particular night over a major city.  A map shows areas of particularly intense activity, and there is a forecast of the total number of birds flying over Colorado. 

To see a live image of birds currently in the air, based on live radar data, go to the affiliated website

Live Radar-based Map