Loggerhead Sea Turtle Nesting Study

Patara Beach is one of the most important nesting beaches in Turkey for the loggerhead Sea Turtle; Caretta caretta. The loggerhead is the most common sea turtle in the Mediterranean. Some of the major nesting sites for this turtle are in Greece, Turkey, Libya and Cyprus.  A recent study has shown information on the nesting activity, spatial and temporal distribution of nesting, nesting and hatching success, nesting density, incubation duration, clutch size, and predation ratio of sea turtles over four nesting periods; 2010, 2012, 2013, and 2014.

Over the four nesting seasons on Patara Beach teams conducted night and morning patrols to determine if sea turtles were laying eggs. The nesting sites were recorded and if the nest showed signs of predation, protection around the nest was set up with metal grates. The number of eggs and hatchlings making it to the sea were recorded as well.

It was found that an average of 179.75 nests were recorded per year. The overall nesting density was 15.50 nests/km while 68.20 loggerhead sea turtle eggs were recorded per nest. The hatching success was 44.05% from these counted eggs and 38.04% made it to the sea. A more detailed result in shown in the table below for each year. 

Table 1. Hatching success and survival of Caretta caretta at Patara Beach over four nesting seasons (N: number of the excavated nests).

Predation was a huge issue in this study. It was found that 53.36% of the nests were affected by predation. Some of the main predators on this beach were foxes, crabs, wild pigs, and wild dogs. These rates and predators differ from other beaches. The metal grate that was used decreased predation and increases the hatchling success. The night patrols conducted also decreases predation pressure. Even after these precautions, if predation is still occurring conservation members can establish an incubation area on the beach. Future research for this study can include further monitoring and conservation studies.

References:

OLGUN, K., BOZKURT, E., CEYLAN, S., TURAL, M., ÖZCAN, S., KARASÜLEYMANOĞLU, K. Ş., & GEROĞLU, Y. (2016). Nesting activity of sea turtles, Caretta caretta (Linnaeus, 1758) and Chelonia mydas (Linnaeus, 1758) (Reptilia, Cheloniidae), at Patara Beach (Antalya, Turkey) over four nesting seasons. Turkish Journal Of Zoology, 40(2), 215-222. doi:10.3906/zoo-1505-8