Adult male sea turtles play a critical role in determining the genetic diversity of sea turtle populations. Male-mediated genetic dispersal has been documented for other sea turtle species and is also presumed for loggerheads; however, little is known about the life history of male loggerheads. As juveniles, male loggerheads are much less frequently observed than females, and typically occur with a 1:3 male to female ratio. It is unclear whether these ratios reflect disproportionate nesting success in warmer, southern beaches where temperature-dependent sex determination would likely produce more females than males, or some other factor. As adults, male loggerheads are reported from spring trawling in the shipping entrance channels of major industrial harbors; however, despite their regular occurrence in such areas, knowledge of local habitat utilization patterns for male loggerheads on the U.S. East Coast is quite limited.
Directed, in-water studies of sea turtles since the 1970’s have consistently collected adult male loggerheads in the Cape Canaveral shipping channel year-round; however, large (greater than 90 cm SCLmin) adult male loggerheads are observed with increased abundances during April and May, presumably for mating. Despite their predictable occurrence, knowledge of distributional patterns of adult male loggerheads at this location are limited to intensive (but short-term) manual tracking and monitoring studies.
Given the critical role that adult male sea turtles play in determining the fate of future generations, the paucity of life history data which exists for adult male loggerheads, the technology now available to both collect and instrument adult male sea turtles with devices suitable for collecting critical life history information, and a known location with high probability of collecting sexually active, adult male loggerheads, we propose to target and collect reproductive adult male loggerheads (as determined by ultrasound and laparoscopy) in the vicinity of the Cape Canaveral shipping channel during April 2007. In addition to standard processing (blood samples for sex/genetics/health; measurements; tagging), we will outfit 9 adult male turtles with satellite transmitters to potentially document mating behavior and migratory routes to and from seasonal foraging areas. Among the questions we wish to address, the following are considered to be especially important to management of this species:
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- 1) Can specific mating areas be identified using satellite telemetry?
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- 2) Do males exhibit localized foraging behavior during the inter-nesting season, followed by long-distance dispersal within the summer season, as documented for nesting females monitored using satellite telemetry at numerous nesting beaches in FL, GA and SC, or do they remain near Cape Canaveral year-round as documented for several adult males tagged in Florida Bay?
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- 3) If males disperse during the summer, do they follow the same routes and/or reach the same destinations as nesting females tagged (with satellite transmitters) on nearby Melbourne Beach?
For more information on sea turtles, check out the Sea Turtles Information section of our website.
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Click on the turtle’s name to see a map of its movements.
ADAM – Adult male loggerhead sea turtle (86.8cm SCLmin; 210 lbs) tagged with a Telonics ST-20 Model A-2010 satellite transmitter on April 3, 2007.
AUSTIN – Adult male loggerhead sea turtle (87.4cm SCLmin; 104.4kg) tagged with a Telonics ST-20 Model A-2010 satellite transmitter on April 28, 2007.
CHRIS – Adult male loggerhead sea turtle (101cm SCLmin; 149.8kg) tagged with a pressure-sensitive Telonics ST-20 Model A-2010 satellite transmitter on April 28, 2007.
COUGAR – Adult male loggerhead sea turtle (102.1cm SCLmin; 172.5kg) tagged with a depth-sensitive Telonics ST-20 Model A-2010 satellite transmitter on April 29, 2007.
DEAN – Adult male loggerhead sea turtle (102cm SCLmin; 147.6kg) tagged with a Telonics ST-20 Model A-2010 satellite transmitter on April 28, 2007.
DR. ABT – Adult male loggerhead sea turtle (89.6cm SCLmin; 106.7kg) tagged with a Telonics ST-20 Model A-2010 satellite transmitter on April 26, 2007.
ELVIS – Adult male loggerhead sea turtle (101cm SCLmin; 149.8kg) tagged with a depth-sensitive Telonics ST-20 Model A-2010 satellite transmitter on April 28, 2007.
HOKIE – Adult male loggerhead sea turtle (89.5cm SCLmin; 95.3kg) tagged with a Telonics ST-20 Model A-2010 satellite transmitter on April 26, 2007.
INGLE – Adult male loggerhead sea turtle (89cm SCLmin; 104.4kg) tagged with a Telonics ST-20 Model A-2010 satellite transmitter on April 27, 2007.
JJ – Adult male loggerhead sea turtle (91.1cm SCLmin; 240 lbs) tagged with a Telonics ST-20 Model A-2010 satellite transmitter on April 5, 2007.
JIM – Adult male loggerhead sea turtle (87.9cm SCLmin; 220 lbs) tagged with a Telonics ST-20 Model A-2010 satellite transmitter on April 4, 2007.
KELLER – Adult male loggerhead sea turtle (93.4cm SCLmin; 245 lbs) tagged with a Telonics ST-20 Model A-2010 satellite transmitter on April 6, 2007.
LEE – Adult male loggerhead sea turtle (87.2cm SCLmin; 230 lbs) tagged with a Telonics ST-20 Model A-2010 satellite transmitter on April 4, 2007.
LIGOURI – Adult male loggerhead sea turtle (86.9cm SCLmin; 86.3 kg) tagged with a Telonics ST-20 Model A-2010 satellite transmitter on April 26, 2007.
McCOY – Adult male loggerhead sea turtle (93.2cm SCLmin; 111.2kg) tagged with a Telonics ST-20 Model A-2010 satellite transmitter on April 27, 2007.
MONTGOMERY – Adult male loggerhead sea turtle (87.3cm SCLmin; 220 lbs) tagged with a Telonics ST-20 Model A-2010 satellite transmitter on April 6, 2007.
QUATTRO – Adult male loggerhead (102.8cm SCLmin; 330 lbs) released with a Telonics ST-20 Model A-2010 satellite transmitter on April 3, 2007.
STANFORD – Adult male loggerhead (90.3cm SCLmin; 250 lbs) released with a pressure-sensitive satellite transmitter (Telonics, ST-20, Model A-2010) on April 2, 2007.
STORTS – Adult male loggerhead sea turtle (102.5cm SCLmin; 145.3kg) tagged with a Telonics ST-20 Model A-2010 satellite transmitter on April 28, 2007.
TONY – Adult male loggerhead sea turtle (107cm SCLmin; 360 lbs) tagged with a Telonics ST-20 Model A-2010 satellite transmitter on April 6, 2007.
More detailed information about the study can be obtained from the Marine Resources Division, South Carolina Department of Natural Resource.
A project of the South Carolina Marine Resources Research Institute.