Satellite Tracking Adult Male Kemp's Ridley Sea Turtles
The Chief of the Division of Sea Turtle Science and Recovery at Padre Island National Seashore led two cooperative studies of the movements of adult male Kemp's ridley turtles captured by net fishermen in waters off Rancho Nuevo, Mexico. Prior to these studies, little was known about the movements, residency, and habitat use of adult males. These were the first two studies ever conducted that employed satellite telemetry to track the movements of adult male Kemp's ridley turtles.
In the first study, movements of 11 adult males were monitored using satellite telemetry between 1999 and 2001 (Click this hyperlink to view the PDF file of the paper "Movements and Home Ranges of Adult Male Kemp's Ridley Sea Turtles (Lepidochelys kempii) in the Gulf of Mexico Investigated by Satellite Telemetry". The majority of accepted locations were in near-shore waters, in 20 fathoms water depth or less. One of the 11 turtles traveled northward and was last located offshore from Galveston, Texas, U.S. The other 10 remained within waters off Tamaulipas, Mexico.
To further investigate the possibility of year-round residency off the Rancho Nuevo nesting beach, the movements of 14 adult males captured during the non-nesting season were monitored using satellite telemetry between 2003 and 2005. Again, most of the accepted locations were in near-shore waters of 20 fathoms water depth or less. Thirteen of the 14 remained within waters off Tamaulipas. The other turtle traveled southward, offshore from Veracruz, Mexico during the tracking period, but returned to waters off Tamaulipas. In contrast to previous findings for adult female Kemp's ridley turtles, these results suggest that a significant proportion of the adult male Kemp's ridley population may reside in the vicinity of nesting beaches in Tamaulipas year-round. Recovery programs for Kemp's ridley turtles should incorporate considerations regarding year-round residency of adult males.
Further research is needed to investigate whether adult males also remain resident year-round in waters off south Texas nesting beaches. During 2006, Padre Island National Seashore tracked movements of an adult male Kemp's ridley that had been captured incidentally in the local area. This turtle left south Texas waters and traveled to off the coast of Louisiana (see www.seaturtle.org/tracking/under the Padre Island National Seashore Kemp's Ridley Project and look for Pierre). During 2008, the National Seashore tracked movements of another adult male Kemp's ridley. This turtle was found stranded at the National Seashore on October 22, 2007, was held for rehabilitation for over 5 months, and then was outfitted with a transmitter and released at the National Seashore on April 2, 2008. This turtle remained offshore from the northern end of North Padre Island and the southern end of Mustang Island during the 2 months that it was tracked (see www.seaturtle.org/tracking/under the Padre Island National Seashore Kemp's Ridley Project and look for Perky). These were the first two adult male Kemp's ridley turtles outfitted with transmitters and tracked after release back into south Texas waters.
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