November in iSimangaliso Wetland Park heralds the beginning of one of the most special and awe-inspiring miracles of this world heritage site – the nesting of endangered turtles on the 220km golden shoreline. Annually, between the months of November and March, heralds the start of the leatherback turtles breeding season.
In this most ancient cycle of life, turtles return with almost magical accuracy to the very same beach where they hatched. The leatherback and loggerhead turtles haul their massive bodies out of the Indian Ocean and up to the base of the dunes, to lay their eggs.
Of the seven species of marine turtles worldwide, iSimangaliso’s protected coastline has five species, and its pristine beaches comprise one of the last significant laying sites in Africa for loggerheads and leatherbacks.
Turtle monitoring has been undertaken in the Park since the 1960’s, with turtles being measured and tagged. The leatherback turtles breeding season is the most important time for conservationists and park officials. The turtles of iSimangaliso have received significant conservation attention, producing a noteworthy increase in the loggerhead turtle population.
“With less than 100 laying females coming ashore each year, iSimangaliso’s leatherback turtles, the most southern population in the world, are rarer than black rhino and critically endangered.
This means they could go extinct in our lifetime. Having survived aeons and ice ages along with rhinos, and at a time when over 1000 biological species are going extinct globally every year, their future survival lies with all of us,” said iSimangaliso CEO Andrew Zaloumis. “As site managers, our challenge is that once they leave our shores and swim across the high seas, they undertake epic journeys, travelling as far as Australia and India.
During these journeys, which occur between nesting periods, the leatherbacks spend their time foraging. They feed on pelagic (open ocean) invertebrates such as jellyfish and this makes them extremely vulnerable to threats such as long line fishing methods and pollution.
Plastic bags are often mistaken for jellyfish by these feeding animals, ultimately killing the animals that ingest them.”
|Summery statistics for Loggerhead and Leatherback turtles nesting in iSimangaliso|
|Population Size||700 females per season||70 females per season|
|Size (average shell length)||86cm||160cm|
|Diet of adult turtles||crabs, snails and starfish||jellyfish|
|Age to sexual maturity||36 years||12 years|
|Breeding frequency (number of years between nesting seasons)||3 years||3 years|
|Reproductive lifespan (number of years between first and last nesting)||18 years||16 years|
|Number of eggs per female over a nesting season||390 eggs||700 eggs|
|Emergence success (percentage eggs that produce viable hatchlings)||80%||70%|
|Number of hatchlings produced per female per season||300 hatchlings||480 hatchlings|
|Total hatchlings produced per year||63 000-144 000||36 000-52 000|
Have you experienced first hand the leatherback turtles breeding season? Seeing this miracle of nature is a moving experience, share with us your experience the largest of all living turtles.
Article by guest author Gwynne Howells, Ezemvelo KZN Wildlife.