Jimmy - 2003

Jimmy's journey

Satellite fixes

Red dots on the map below will indicate the turtles location from clear readings taken from the tracking device. Dates shown on will be in year/month/day format, i.e. 20020917 means 17 September 2002.

Jimmy update, 30 September 2003

Satellite telemetry results for JIMMY (adult male loggerhead turtle, T53798)

Figure 1: Satellite telemetry results for JIMMY (adult male loggerhead turtle, T53798).

Jimmy is an adult male loggerhead turtle originally captured while feeding on 6 September 1991 on the southern Moreton Banks. He was recaptured on four additional occasions while feeding on 15 September 1996, 5 April 1998, 4 May 1998 and 20 May 2003 over a period of 11.7 years. All captures have occurred within the southern Moreton Banks. He was released with a satellite tracking radio transmitter (PTT) in Moreton Bay on 24 May 2003 (Figure 1) at Cleveland Point. This release site was 16.63 km from the site at which he was most recently captured on the Moreton Banks:

  • 24 May: Released at 15.27 hours with the PTT attached to carapace at Cleveland in south-western Moreton Bay. He moved offshore into Raby Bay.
  • 25-31 May: Moved within a small area (6 km diameter) in central Moreton Bay within 10-25m depth range.
  • 1 June: Jimmy swam east across the southern Moreton Banks in the area where he had been previously captured. He continued eastward to exit Moreton Bay via South Passage between Moreton Island and North Stradbroke Island.
  • 2 -16 June: Arrived at and remained within a 2km radius of Flat Rock Reef with its surrounding waters in the 10-50m depth range.
  • 17-30 June: Unexplained change in transmissions. No new good quality fixes many poor quality fixes received.
  • 6 July: Seen at the surface by Alan Goldezen while he was at Flat Rock for a dive. The PTT appeared to be in good condition.
  • 7-31 July: Only one accurate fix received from Jimmy in this period: approximately 5km northwest of Flat rock and approximately 9.5km east of the southern tip of Moreton Island. Poor fixes were received on most days.
  • 1-31 August: Four accurate fixes received from Jimmy in this period. He has generally remained in the vicinity of Flat Rock. On 31 August, he was 10km east of Flat Rock. This is the greatest distance off shore recorded for Jimmy. Poor fixes were received on most days.
  • 1-3 September: Nine accurate fixes received from Jimmy in this period. Jimmy has returned back inside Moreton Bay after 3 months outside around Flat Rock. Within the Bay, while he has visited scattered sites on the Maroom Banks and Chain Banks, Jimmy has been mostly recorded in the vicinity of Browns Gutter on the southern Moreton Banks. The improvement in reception of signals is probably the result of him moving back into calmer water.
  • November - December: Batteries running down. No further locations received.
Leisel Jones and Minister Dean Wells with JIMMY, an adult male loggerhead turtle fitted with a satellite tag for tracking his movements within Moreton Bay. Jimmy was named after Leisel's grandfather.

Leisel Jones and Minister Dean Wells with Jimmy, an adult male loggerhead turtle fitted with a satellite tag for tracking his movements within Moreton Bay. Jimmy was named after Leisel's grandfather.

Background information

Jimmy is one of a series of six adult male loggerhead turtles resident in Moreton Bay that have been fitted with radio tags (PPT) and released for tracking studies using satellite telemetry via the ARGOS satellite system during 1998-2003. The first five turtles were in an active spermatogenic cycle, i.e. males preparing to breed in spring 2002, when selected for this study. The objectives of this study are, battery life permitting:

  • To quantify the home range for a loggerhead turtle foraging in subtropical waters in Moreton Bay;
  • To identify the path and duration of the breeding migration from the feeding area to his courtship area during spring 2002;
  • To quantify the home range of the courtship area and the duration of the courtship period.
  • To identify the path and duration of the post-breeding migration from the courtship area to his post-breeding foraging area;
  • To quantify the post-breeding foraging home range of this turtle and determine its fidelity to a specific feeding area(s) across breeding migrations.

Jimmy was selected as a male not preparing for a breeding season, to ascertain whether non-breeding males have a similar sized home range as males that are preparing for a breeding season.

T53798, Caretta caretta (Jimmy)

  • 6 September 1991: adult male captured while feeding on southern Moreton Banks in Browns Gutter; carapace length = 94.6 cm.
  • 15 September 1996: captured while feeding on southern Moreton Banks in Fisherman's Gutter; he had been hit by a boat since his last capture.
  • 5 April 1998: captured while feeding on southern Moreton Banks adjacent to Rous Channel.
  • 4 May 1998: captured while feeding on southern Moreton Banks captured while feeding on southern Moreton Banks adjacent to Rous Channel.
  • 20 May 2003: adult male not in an active spermatogenic cycle (= not preparing to breed in spring 2003), CCL=95.0 cm; weight=105 kg; captured in inter-tidal waters of the southern Moreton Banks, sector 1 at Weedy Gutter. He had been hooked with gang-hooks in the right hind flipper since his last capture.
  • During the 11.7 years since his first capture, this adult turtle grew 0.4 cm.
  • PTT identification = 41563.
    • Sirtrack Kiwisat 101 PTT powered with c cell batteries.
    • Duty cycle: Continuous operation for the first 30 days followed by 6 hours on / 18 hours on for the remainder of its battery life. Switched on at 0215hr EST on 19 May 2003.
    • Repetition cycle: =30 seconds.
    • PTT weight = 0.63 kg
  • 24 May 2003: released from Cleveland Point at 15.27hr EST, 16.63 km from his recent capture site.

Turtle transmitter sponsored by Seaworld Research and Rescue Foundation