Sunday, July 23, 2017

Fall migration milestone: first Yellow Warbler reported

Although some migratory shorebirds are usually reported back weeks earlier (see my late June post), to me one of the pivotal moments of each fall migration is the first report of a Yellow Warbler.

One was reported in St. Tammany yesterday, by Jane Patterson in her back yard.

I normally expect to hear of a Yellow somewhere in the state at the very tail end of  July, but this one was a few days earlier than I anticipated.   It is the onset of a larger movement-Yellow Warbler normally seems to me the most numerous August migrant in the New Orleans area.  Because it is also one of our migrant species with the greatest propensity for "morning flight" (active migration in the early AM), it is not unusual to hear one giving its seet note overhead on any morning during the month.  I have spent many hours listening for these birds in many locations on August mornings, and have on occasion observed movements of up to 100/hour both on the lakefront and in Old Jefferson.  Most such birds appear to be westbound, and presumably are bound to circumnavigate the Gulf.  They do also stage larger corrective flights at South Point on August mornings with northeast winds, but such winds are hard to come by so early in the season, since we are generally still out of range of the cool fronts that create them.  I have long tried to figure out when during August the peak of Yellow Warbler numbers occurs; my best guess is that it is in the last few days of the month, but because substantial flights can occur earlier, I am still wondering.