240 OSPREYS: Top 3rd Day Count!

South-bound migration was the agenda for Ospreys moving through the Florida Keys today. Inclement weather and unfavorable winds appeared to have had a bottleneck effect on migrating raptors the day before. The total number of Ospreys detected at the hawkwatch on September 12, 2014: one. And the day before that brought a respectable thirty-eight.

Ospreys migrating over the Middle Keys. Photos by Rafael Galvez. Leica V-Lux 4.

Ospreys wasted no time making up for a day spent hunkered down farther north the day before. When the hawkwatch opened at 9:00 am, Ospreys were already on the move; in the first two hours, 135 were detected. Numbers of them would remain consistent throughout the day, and as thermals began to form, we began seeing birds at higher altitudes. Small groups could often be seen riding thermals with Magnificent Frigatebirds, gaining height with every wide turn. Then, one-by-one at the most favorable height above Earth’s surface, they would follow the same trajectory for landmasses farther afield. Once in a strong glide, one could watch an Osprey disappear to the south, all without one beat of a wing. The birds also seemed to be following two different flight lines. The majority appeared to be following the Keys, island hopping possibly until reaching the Lower Keys before making the jump to Cuba or Central America. But as the day went on, we saw more and more making a bee line for Cuba. Apparent Cuba-bound birds also seemed to be the highest-flying on average. Birds following the Keys appeared to be cruising at lower altitudes.

By the end of the day, the hawkwatchers would tally 240 Ospreys. This number makes for the third highest day total for the Florida Keys Hawkwatch, and only nine behind the second highest (249 on 9/25/2002). A lull in southbound activity around 4:00 pm made beating the second highest total seem a bit more distant. It wasn’t until driving north on US-1 towards Long Key that we could see just how many Ospreys were still moving through the Keys. Forty-six more were located between Marathon and Long Key, most of which were southbound. Yet another storm had been keeping these birds from moving south as the afternoon went on, so who knows what the end-of-the-day count could have been?

 CLICK IMAGE TO PLAY VIDEO. Above, a resident “Ridgway’s” Osprey kept an eye on the sky as migratory birds of its species continued moving overhead. Often, as it spotted a migrating Osprey, it would make a plaintive call. To learn more about this Caribbean subspecies, read “Observing Ospreys,” by Jeff Bouton. Video by Rafael Galvez – Leica V-Lux 4.

Top 5 single-day counts for Osprey (Pandion haliaetus) from the Florida Keys Hawkwatch at Curry Hammock State Park – spanning the project’s entire history at that site.