31 December 2011

The Loggerhead Turtles of Mon Repos

Friday, 30 December 2011

Late start to the day, we were in no hurry today as we knew we would be staying up very late.
There were a few things to do around the camp: washing, mending equipment, general tidying up to allow for a hassle-free departure the following morning.

After a late lunch and an afternoon nap we headed over to Mon Repos just after 18:00 (6:00PM).
Lots of people were already queuing, lots more were still arriving as we were taking in the atmosphere and a cup of coffee from Robby's “Vantastic Food” outlet outside the Mon Repos Information Centre.

Eventually the gate was opened and visitors were welcomed into the centre after checking their respective booking details. Tonight's turtle encounter was fully booked. When we were handed our numbered stickers we found out that we were in group 4 – it would be a long night for us as group 1 was to be led onto the beach first and turtles weren't expected to emerge from the sea before 21:00 (9:00PM).

In the amphitheatre outside we watched an introductory film on turtle research and conservation at Mon Repos. 95% of the female turtles that come on the beach over night for breeding are Loggerhead Turtles (Caretta caretta), an endangered species. If we were going to see a turtle tonight, it would be a loggerhead.

Shortly after 21:00 (9:00PM) the first group was called to assemble at one of the boardwalks that lead onto the beach, the first turtle had emerged!

A little while later Flip had the opportunity to join Mon Repos' junior ranger program.Flip and the other children got an insight into turtle research and filled in a data collection sheet after carefully examining the fibreglass model of an egg-laying loggerhead.

Outside we listened to another talk on the characteristics of Loggerhead Turtles, particularly their breeding pattern and quite extraordinary life cycle, all preparing us for the real life encounter.
Then it started to rain. In between showers Shane, the QPWS ranger in charge of the night, was receiving radio calls from turtle-spotting staff based on the beach, researchers and volunteers. He would then go on to assemble groups and send them onto their way into the night.

Eventually, at 23:15 (11:15PM) it was our turn.
Group 4 met at the gate to the northern boardwalk. Instructed not to turn on any lights we shimmied down the sloped boardwalk, slippery with rain and sand, onto the beach in complete darkness. The moon had set already, the stars were obscured by clouds.
Once on the beach we waited for a few minutes only to be told by our guide Shane that we had to return to the information centre.
The turtle our group had been assigned to had changed her mind and gone back in the water.

But a short time later we made our way down the wooden planks again and we were led to a site a few hundred metres north. We could see a few lights up there as we were walking through the sand, the rain becoming stronger once again.
The turtle had already completed laying her eggs when we arrived at her nesting site.
Bummer...we thought...

But there were a couple of reasons why the rangers hadn't called us in earlier, why they didn't want too many people around this turtle too early in the night.

This particular female Loggerhead Turtle had been on the beach the previous night. But something had spooked her and she'd decided to do a U-turn and swam out into the dark again.
So when she emerged again tonight, they wanted to make sure everything went to plan.

Loggerheads dig their nests above the high water mark, up in the dunes where the sand is soft and doesn't get inundated in the event of a storm surge.
They usually clear any grass and debris from their chosen site and dig a body pit before they proceed with the digging of the egg chamber, up to 60cm deep, by use of their rear flippers – the hard yakka.

Our turtle (who is easily identified by the tag number on her flippers) is known to have a “glitch” in her nesting sequence, this complex set of instinctive behaviour embedded in a turtle's DNA.
She digs the body pit – but then she skips the crucial part of of digging the deeper egg chamber!
In order to improve the survival rate of her offspring Barry and a couple of other volunteers had helped her out by digging the hole for her, right under her stubby little tail, so her eggs would drop into the safety of a sufficiently deep egg chamber. She had already started to fill in the hole again when we appeared on the scene.

This is the time of night when photos of nesting turtles can be taken without causing too much of a disturbance.

Our guide, very knowledgeable and truly passionate, provided us with information on this turtle lady.
She was tagged when she first emerged from the South Pacific in the year 2002. After her “lost years”, the 30-35 years between hatching and reaching sexual maturity, she'd found the beach with help of her inbuilt GPS that recognises the Earth's magnetic fields. Since then she has returned to the scene every second year.

Tonight she actually laid her second clutch of eggs for the season, over 100. And she may even return in a couple of weeks for a third clutch.

About 8 weeks from now this clutch will hatch, baby turtles will work their way through the sand – and in the cover of night they will make a mad dash for the water.
Some of the hatchlings will have their DNA samples taken to determine how many different male turtles contributed their sperm to the hatchlings of this clutch.

After obscuring the nest, she started to make her way back to the water. For a moment she wandered in the wrong direction but after we'd all turned off our lights and cameras, she found her way back down to the waves, guided by only Shane's torch light. And then she was gone, swallowed up by the sea.

We didn't encounter any other turtles on our way back to the information centre. We were soaked with rain. We had an unforgettable night.

Boh boh!

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