Thanks for tuning in as I finally get this blog rolling! (Head over to the “What is this?” page for a little background.) We still have a few weeks to go before peak migration really kicks in, but things have been afoot for some time already. I’ve actually been monitoring migratory activity via radar since mid-February–mostly small-to-moderate flights of early “temperate migrants,” visible mostly by night (e.g. juncos) but also by day (e.g. robins, blackbirds). Now that we’re well into March, some Neotropical migrants have started trickling in as well. Purple Martins have been back in Mississippi since February, the first Northern Parulas were spotted a week or two ago, and a few Black-and-white Warblers have just turned up.

For a taste of what’s already happened this spring, check out this animation of local activity on the night of March 2nd, and this animation of nationwide migration on the same night. March 2nd provided classic weather conditions for a strong mid-South migratory flight: warm temperatures and strong southerly winds, as you can see from the weather maps from about sunset that evening. In watching the animation of nationwide activity, you can clearly see the migration-squelching effects of a cold front and the strong north winds that typically follow.

(NOTE: The highest reflectivity values in this image, represented by dark green, correspond to bird concentrations of about 1800 per cubic kilometer.)

Just after sunrise the following morning (March 3rd), another phenomenon is visible: a cloud of what appear to be birds departing the Jackson area and traveling northward quite rapidly. My guess is that this was a subgroup of grackles, blackbirds, and/or cowbirds (daytime migrants) leaving their large winter roosting areas near Jackson’s Lake Hico.

The events of the night of February 29th warrant special mention. Many fewer birds were in the air that night, but those that were had to contend with a cold front and associated squall line that moved across Mississippi during the peak migration hours. You may interpret the animation differently, but I believe that one can see large numbers of birds coalescing and “stalling” as they sense the approaching storms (at a distance of 10 or 15 miles), and ultimately aborting their flight. (Watch the areas south of Jackson as the front moves through at about 10 PM). This stands out more clearly in a still image from 10:30 PM:

Tonight, winds will be from the southeast; look for a moderate flight over Mississippi. Meanwhile, strong upper-level southerlies over the Gulf of Mexico could generate a fair trans-Gulf flight of Neotropical migrants (although it’s still quite early in the year); watch the Houston, Lake Charles, New Orleans, and Mobile radars for incoming birds tomorrow morning. Later this week, interesting events may develop as a deep trough of low pressure brings some potentially violent weather across our part of the country.