Success of Delayed Translocation of Loggerhead Turtle Nests

Abstract Sea turtle embryo mortality in natural nests due to environmental and anthropogenic factors can be very high. To increase hatching success of these endangered species, nest translocation to hatcheries immediately after egg-laying is a common management tool. To test the viability of delayed translocation, we moved 50 loggerhead  sea turtle (Caretta caretta) nests to a beach hatchery after various times (0–96 hr) after egg-laying at Boavista Island (Republic of Cabo Verde, western Africa). We transported eggs in a rigid plastic container, being careful to maintain their original vertical orientation. Delayed translocation times of 0 hours, 12 hours, 24 hours, 84 hours, or 96 hours after egg-laying did not have any effect on hatching success, incubation period, or hatchling size and mass. Delayed translocation slightly increased the duration of the translocation process because of extra precautions taken (e.g., maintaining axial orientation, protecting eggs from mechanical shocks). We conclude that delayed nest translocation can be done in a safe and effective way, thereby increasing the efficiency of the whole monitoring program. Finally, delayed translocation, accompanied by an evaluation of fertility, would seem to permit the removal of undeveloped eggs and to facilitate their subsequent exploitation by local communities without affecting turtle nesting success.

[1]  L. López-Jurado,et al.  Why are egg fertilization rates not correlated with hatching success in sea turtles , 2006 .

[2]  S. West,et al.  The effects of incubation environment, sex and pedigree on the hatchling phenotype in a natural population of loggerhead turtles , 2002 .

[3]  D. Cejudo,et al.  Distribution of marine turtles in the archipelago of Cabo Verde, western Africa , 2002 .

[4]  D. Booth,et al.  Incubation temperature, energy expenditure and hatchling size in the green turtle (Chelonia mydas), a species with temperature-sensitive sex determination , 2001 .

[5]  D. Booth,et al.  Temperature variation within and between nests of the green sea turtle, Chelonia mydas (Chelonia: Cheloniidae) on Heron Island, Great Barrier Reef , 2001 .

[6]  D. Cejudo,et al.  Proposals for the Conservation of Marine Turtles on the Island of Boavista (Republic of Cabo Verde, Western Africa) , 2000 .

[7]  N. Mrosovsky,et al.  Validation of incubation duration as an index of the sex ratio of hatchling sea turtles , 1999 .

[8]  J. Miller.  Determining clutch size and hatching success , 1999 .

[9]  J. Mortimer.  Reducing Threats to Eggs and Hatchlings: Hatcheries , 1999 .

[10]  N. Mrosovsky,et al.  Estimating sex ratios of loggerhead turtles in Brazil from pivotal incubation durations , 1997 .

[11]  Karen L. Eckert,et al.  Embryo mortality and hatch success in in situ and translocated leatherback sea turtle Dermochelys coriacea eggs , 1990 .

[12]  E. Chan.  White spot development, incubation and hatching success of leatherback turtle (Dermochelys coriacea) eggs from Rantau Abang, Malaysia , 1989 .

[13]  C. Limpus,et al.  Low-Temperature Protection of Marine Turtle Eggs During Long-Distance Relocation , 1989 .

[14]  Michael Salmon,et al.  Egg Failure in Natural and Relocated Sea Turtle Nests , 1988 .

[15]  S. Morreale,et al.  Temperature-dependent sex determination: current practices threaten conservation of sea turtles. , 1982, Science.

[16]  R. Sawyer,et al.  Hatchery practices in relation to early embryology of the loggerhead sea turtle, Caretta caretta (Linné) , 1981 .

[17]  N. Mrosovsky,et al.  Temperature dependence of sexual differentiation in sea turtles: implications for conservation practices , 1980 .

[18]  C. Parmenter.  Incubation of the Eggs of the Green Sea Turtle, Chelonia Mydas, in Torres Strait, Australia: the Effect of Movement on Hatchability. , 1980 .

[19]  U. Raj.  Incubation and hatching success in artificially incubated eggs of the hawksbill turtle , 1976 .