Friday, February 3, 2017

Northbound race to breeding sites: Swallow-tailed Kites have started their migration!

It’s that time of year again when we see those familiar GPS fixes in South America begin edging northward. For several years, ARCI has been monitoring satellite-tracked Swallow-tailed Kites on their wintering grounds in South America. We always know that within the last two weeks of January we can expect some of them to begin their migration back to the southeastern United States.

Right on time, the first bird to start north on 17 January was Bullfrog from Tampa Bay Florida, two days earlier than last year. She was our northern-most wintering kite, in Mato Grosso do Sul, Brazil. Today, she remains farther north than any of our tracked kites, along the Bolivian border in the northern part of Rondônia state, Brazil.

GPS-tracking data for six Swallow-tailed Kites during the month of January, 2017 in South America and the start of their northbound migration back to breeding sites in the southeastern U.S.
MIA, from Miami, Florida, started north on 18 January. Even though he wintered 225 miles south of Bullfrog in Brazil, he traveled faster and is probably less than 6 hours behind Bullfrog.

Lacombe, tagged in Louisiana by our colleague Dr. Jennifer Coulson, began moving north on 28 January. He appears to be taking a more westerly route across Brazil’s famous Pantanal, where he now resides, in northern Mato Grosso do Sul.

Palmetto, tagged near her nest in South Carolina in 2011, remains on her winter range near Santa Rita do Pardo in Mato Grosso do Sul. MIA, Lacombe, and Palmetto spent most of the winter within the same area, using the same foraging and roosting sites, where they were joined by Panther in late December.

Panther, from the Florida Panther National Wildlife Refuge in Collier County, is also edging north and last uploaded GPS locations on 26 January from Rondônia, Brazil, where she was only 15 miles away from Bullfrog. Because Panther and Sawgrass transmit their data via cell towers rather than satellite, we have not yet received the entire location track for this bird. GPS data are collected even when the transmitter is too far from a cell tower. The backlogged data will begin uploading once the bird comes within range of the next tower. However, the bird may move beyond range of that tower before the upload is complete, thus requiring a succession of uploads before all the data get delivered.

Our most unusual wintering Swallow-tailed Kite movements come from Sawgrass, a female tagged in St. Petersburg, Florida. She resided in southern Bolivia along the Argentinean boarder where none of our previously tracked kites have wintered. On 8 January, she wandered east across Paraguay to Amambay Department, where she has been since 17 January. This is 180 miles southwest of the four communal Swallow-tailed Kites in Brazil.

The race is on! We hope these Swallow-tailed Kites have an easy journey back to their breeding grounds in the Southeastern U.S. We’ll keep you posted. Buen viaje!