Movements of six Magnificent Frigatebirds tracked by satellite

By 15 May 2013, all but one of the four Magnificent Frigatebirds we tagged in the Florida Keys had returned to Florida from their breeding sites in Mexico. Keys #5, a female who presumably nested in the Archipielago de los Jardines de la Reina in southern side of Cuba, returned to Florida on 4 July 2013. She spent the majority of her time in the western Great White Heron NWR until 24 October, when she returned to her breeding area in southern Cuba. This was a relatively quick visit as she then moved to the north coast for a week before returning to the Florida Keys on 2 December. Since females are unable to breed every year, it is not surprising that she would not remain in a nesting colony during the breeding season.

Other than a 24-hr round-trip to Veradero, Cuba. and a three-day visit to a nest colony Isla Contoy, Mexico (northeastern Yucatan Peninsula) in mid-November, Keys #6 stayed in the Florida Keys until 28 November. It was unclear whether she was nesting, but at the least she habitually used a small number of perching locations.

Gina Kent works to outfit a satellite tracking device to a Magnificent Frigatebird at Dry Tortugas National Park.

Keys #7 kept to the central part of the Great White Heron NWR, although she did spend some time west of Key West, including the night of 9 July in the Dry Tortugas. Keys #7 left the Florida Keys on 28 November and headed directly to Cayo Culebra off the Yucatan Peninsula, where she appears to be nesting. She has the most extensive foraging area of all of our wintering Magnificent Frigatebirds, ranging over 250 miles off shore on trips of three, four, and over six days at sea.

Keys #9 roosted within the Great White Heron NWR as well and foraged up into Florida Bay, as most of the other frigatebirds we are tracking. On 30 November he flew directly to Isla Contoy, Mexico. He is exhibiting strong fidelity to a well-defined area and well may be nesting. Since the end of December, he has started to make some longer foraging trips, which may indicate that there is a nestling to feed.

The tip of the transmitter’s antenna can seen (between the tail and to the left) on this female Magnificent Frigatebird.

We know that the Dry Tortugas female (DRTO Female) attempted to nest in 2013, and she has been restricting her foraging activities to within 30 miles of the Dry Tortugas. Occasionally, she flies nearly 50 miles to the Marquesas Keys for one night and returns to the Dry Tortugas the next day.

The Dry Tortugas male (DRTO Male) left on 20 May for Seahorse Key in Levy County, Florida (just seaward of the town of Cedar Key). He stayed on this roosting island until 6 September then returned to the Dry Tortugas briefly before moving east to the Great White Heron NWR and the Florida Bay immediately to the north. During the fall, he wandered north along the Atlantic coast to points near Miami and as far north as Fort Pierce. As of 14 January, he has remained in the Fort Pierce area.