Tuesday, March 6, 2018

Ready to Return

Before reading on: Be sure to familiarize yourself with the eleven Swallow-tailed Kites we’re tracking in last week’s blog, “New and Familiar Feathers”.

In September 2017, our attention turned to the effects of Hurricane Irma, and reporting the progress of our tagged Swallow-tailed Kites’ southbound migrations fell through the cracks. We’re happy to tell you all eleven individuals safely reached their respective wintering grounds in South America. Nine Swallow-tailed Kites left from the southern tip of Florida to cross the Gulf of Mexico, a familiar route many tagged birds have taken in previous years. Lacombe and Bogue Falaya, both from Louisiana, skipped the ocean option and instead took the less-risky path over land, down the east coast of Texas and Mexico, ultimately rejoining the rest of the southbound birds from the US population.
Southbound-migration paths of ARCI's eleven tagged Swallow-tailed Kites, 2017. 
Environmental and biological triggers tell Swallow-tailed Kites to migrate each season; however, each individual’s itinerary looks slightly different. Babcock crossed the Gulf of Mexico first on 13 July 2017. Two weeks later, Refuge and Panther followed, leaving Florida hours apart. Palmetto, MIA, Lacombe, Sawgrass, Sarasota, Bogue Falaya, and Wilson left throughout August. Last but not least, Apopka jetted south just three days before Hurricane Irma hit Florida on 8 September.

Babcock may have left two weeks earlier, but Lacombe, Palmetto, MIA, Panther, and she reached the State of Mato Grosso do Sul, Brazil, within 5 days of each other in early October. Next came Sawgrass, who leisurely joined the others in mid-November. Sarasota, who was in the State of Amazonas in western Brazil in October, reached Mato Grosso do Sul in January 2018. These seven Swallow-tailed Kites all used the same 700 square-mile patchwork of ranchlands and remnant forests.

Three kites, Apopka, Refuge, and Bogue Falaya, over-wintered in the State of Rondônia, about 800 miles north of the wintering grounds in Mato Grosso do Sul. Here the landscape is a mosaic of farms and forest as well. Speeding through Central America, Bogue Falaya wasted no time in reaching Rondônia in early October. Apopka, who left last and spent a few extra days in Cuba, likely waiting for favorable winds after Hurricane Irma, reached Rondônia in early November. Refuge spent September and October on the northern border of Bolivia and Peru, then moved west to join Apopka and Bogue Falaya in December. Wilson spent October in Rondônia, but moved on to the State of Mato Grosso in November, where he stayed until January.

We waited patiently for the data to suggest the restlessness commonly observed in migratory birds about to make their seasonal moves. On 19 January 2018, MIA was first to move north out of his wintering grounds. MIA began his northbound migration on this exact day in 2017. Palmetto did the same, leaving on 2 February in both 2017 and 2018. Talk about consistency! This is most likely due to the kites’ sensitivity to day length as a way to time their migration departures.

The location of 11 tracked Swallow-tailed Kites as of 5 February 2018.
Lacombe left Louisiana on 21 January, one week earlier than in 2017. Panther left one day later than her 2017 departure on 18 January. According to her latest data, Sawgrass remains on her wintering grounds as of 28 January. We expect her to make a move soon (last year, she started north on 10 Feb).

For the six Swallow-tailed Kites tagged in 2017, this is our first glimpse into the paths they will take on their northbound journeys. We hope all of them have uneventful journeys.