“It was such a privilege to have the experience of watching a turtle nesting and something that will remain with us for a long time.” – Guest Review from TripAdvisor
“The majestic turtle experience was one of the most special wildlife experiences I have ever had the privilege of watching.” – Guest Review from TripAdvisor
Scroll down for more information on our turtle tracking experience at Thonga Beach Lodge!
TURTLE MONITORING IN THE iSimangaliso WETLAND PARK
During turtle season (Nov-Feb) we arrange one turtle drive every night at low tide. Due to the concession legislation we have access to the beach at the low tide mark for 4 hours. We are permitted to drive the length of the beach looking for the females and the hatchlings. There is a charge for the turtle drives but no charge for turtle walks.
Night drives are tide-dependent and may happen just after dinner or in the early hours of the morning and can sometimes be as long as three hours
Both loggerhead and leatherback turtles nest during the summer months at night (November – February). Steep beach faces make it easy for loggerheads to swim through the surf over low lying rock ledges. The females emerge from the surf and rest in the wash zone on the beach. Here they assess the beach for any danger by lifting their heads and scanning the beach. Satisfied that there is no danger they then proceed up the beach to well above the high water mark.
Having found a suitable site, the female commences by excavating a body pit, this enables her to lie with the top of her carapace level with the beach. She then digs an egg cavity with her hind flippers. The egg pit is a flask shaped hole about 50-80 centimetres deep. A normal clutch constitutes 100-120 soft white shelled eggs which are deposited into this hole. When all of the eggs have been laid the female fills the hole with sand and kneads the surface until the sand is packed hard. Once this is done, she disguises the nest site by throwing sand with her fore flippers over the nesting area. Leatherbacks can return up to seven times to lay eggs, while loggerheads return up to four times in a single season.
Loggerhead turtle eggs take between 55-65 days to mature and leatherback turtle eggs take between 65-70 days. Once ready to emerge the hatchlings cut their way out of the egg with a special egg tooth on the end of their beaks. After the bulk of the eggs have hatched the hatchlings start digging at the sides of the nest. The hatchlings will often wait during the heat of the day, until the sand has cooled before emerging and heading to the sea.
The most serious threats that are present at various life stages
- Nesting – Egg collecting, slaughtering for meat, coastal development, sand mining and beach driving
- Home Ranges – (coral reefs, sea grass beds, open oceans) These are disturbed or destroyed by bad fishery practices, pollution and global warming.
- Migration Movements – Their migration routes are threatened by trawlers or drift nets and long lines.
- Littering in the Sea – The leatherbacks feed mostly on jellyfish – with the serious problem of plastic bags littering our seas, the bags are often ingested by turtles who choke on this toxic waste.
Types of Turtles
Loggerhead Turtle (Carettacaretta)
Loggerhead turtles are a lot smaller than leatherbacks however they are the world’s largest hard-shelled turtle. Their weight ranges between 80-200 kg, with a length of 70 -95 cm. However, the maximum recorded weight of a loggerhead was 545 kg with a carapace length of 213 cm.
Loggerhead turtles inhabit the Atlantic, Indian and Pacific Oceans, as well as the Mediterranean Sea.
Their average dive duration is 15-30 minutes however researchers have recorded them submerged for up to four hours.
Loggerheads spend most of their time in open ocean and shallow coastal waters, they rarely come ashore except for the female’s brief visit to dig nests and lay their eggs. Nesting takes place at night from the end of October through to January. The round, white, leathery eggs – as many as 120 in a clutch – are laid in the sand and then covered with packed sand. The females come ashore and lay up to 500 eggs in 15 days intervals. The juveniles hatch after 55 days and head out to sea.
Loggerhead turtles are omnivorous, subsisting mainly on bottom dwelling invertebrates. Due to their particular diet, they have a large head with strong powerful jaws to crush their prey. Scale points or claws on the anterior margin of their forelimbs assist them greater with manipulation of their food and the male uses them to hook onto the female whilst mating.
Leatherback turtles are the largest of the turtles in the oceans of our planet, they are the largest reptile other than three species of crocodile. The largest recorded length of a leatherback was 3 metres from head to tail with a carapace length of 2.2 metres. This particular turtle weighed in at 916 kg, however typically they weigh between 250 to 750 kgs.
They are the fastest moving reptiles and travel vast distances between their feeding grounds and nesting beaches. Scientists have tracked a leatherback turtle that travelled 20 000 km in 647 days. A leatherback from our Maputuland coast was fitted with a GPS transponder and its journey was recorded to travel from Maputuland to Angola on the West Coast of the African continent.
Out of all turtles, leatherbacks dive the deepest. One leatherback has been recorded to dive 1 280 metres, making them one the deepest diving marine animals. Typical dive durations are between 30 and 85 minutes.
As its name implies, a leatherback turtle does not have a bony carapace shell like other turtles, its back is covered in a dark grey to black leathery and oily skin. Female leatherbacks prefer soft sandy beaches because of their soft leathery backs. Females will lay as many as 10 clutches in one breeding season, each clutch with an estimated 80-100 soft shelled eggs. Both the leatherback and the loggerhead go to great lengths to disguise their nesting sites.
Leatherback turtles subsist almost entirely on jellyfish.
Loggerhead and Leatherback Turtle Monitoring
Seven species of marine turtles exist in the world’s oceans today, therefore turtles are important indicators of ocean health. There are five species found off the Kwa-Zulu Natal Coast, namely, the loggerhead, leatherback, hawksbill, green and olive ridley turtles. Of these five species that occur in South African waters, only the loggerhead and leatherback females nest along our shores.
Monitoring Turtles for 40 years
From the early 1960’s, concerted efforts were made to enforce legislation banning egg collection and the harvesting of adults. In 1963, under the auspices of the Natal Parks Board, a Turtle Conservation and Monitoring programme was initiated along the north- eastern coast of Kwa- Zulu natal which is now the iSimangaliso Wetland Park.
The purpose of the project
To monitor and record nesting populations of loggerhead and leatherback sea turtles along the eastern seaboard and simultaneously provide protection of the females during this vulnerable stage on the shore.
The 56 kilometer of beach, north and south of Bhanga Nek, in the iSimangaliso Wetland Park, is the main focus area of the project.
After the incubation period the nest breaks open and the hatchlings emerge – the sex of the hatchlings, like crocodiles, is determined by the temperature within the nest but with opposite results. Females occur between 32-34 ºC and males occur in cooler temperatures. The success rate of the hatchlings is very low. One of the biggest threats is the honey badger that patrol the dunes for nests. The nest often opens at night to minimize predation by crabs and birds. Once in the sea the hatchlings are at risk from fish and squid and because of all these factors it is estimated that maybe two of each annual nesting survive to become an adult.