Monday, July 16, 2018

National Parks: Padre Island National Seashore -- Turtles Part 2

The Kemp's ridley sea turtle is most critically endangered sea turtle. It is also the smallest and rarest. I've been to enough presentations and read the materials to summarize the history of this species:

Once, Spanish conquistadors reported having to lower their sails as to not crash into the massive herds of Kemp's ridley sea turtles that seem to swamp the Gulf of Mexico. But no one knew where they nested. For a long time, it was thought that these turtles were probably the infertile hybrid of other turtle species. But then fishermen found that these turtles were pregnant with eggs. So they were a species, but no one knew where these mysterious turtles nested.

In 1940s, Architect Andreas Herrera, who regularly visited Mexico and flew his own plane, was hunting down leads of where this turtle was sighted emerging from the sea. In the summer of 1947, he made an incredible discovery. At Nuevo Rancho beach in Tamaulipas, Mexico, he witnessed thousands of these sea turtles emerging from the sea. He recorded the event on film. He tried to spread the word to the scientific community and leaders to do something to protect the sea turtles.

He was concerned that in addition to seeing the thousands of sea turtles, he recorded many people digging up the eggs, flipping over the big turtles, and taking the turtles to butcher for meat and to eat and sell their eggs, supposedly for aphrodisiac purposes!

By the 1960s, scientists finally discovered the film and raced down to see the Nuevo Rancho site. The film recorded an estimated 45,000 sea turtles in 1947. When the scientists got there in the 1960s, the population had plummeted to only 700! Poaching, unsound fishing practices, and other factors had destroyed the population and put them on the brink of extinction!

Emergency action was taken by many concerned people to save the species. And so, the work began to save the Kemp's Ridley Sea Turtle. And that work continues to this day. And though the turtles are slowly recovering, they still need our help. We can be better people and help save the species.

The nets and streamers keep the predatory birds, like pelicans and especially those filthy flying rats--seagulls--from swooping down to eat the little hatchlings. We are told beforehand by the park rangers not to wave our hands to chase away the seagulls. The seagulls have learned from watching humans that the waving of hands means that there is food to be taken! That's why there are signs posted not to feed the animals, because then, animals like seagulls will lose their instinctive fear of humans and start targeting people for food, swooping down to steal them! Even worse, some human food is very bad for birds! So please listen to the park rangers and stop feeding the damn seagulls!

Dr Donna Shaver and the team release the hatchlings right as the sun rises, to help the hatchlings imprint on the beach and learn to come back to this location for nesting. Notice how the team wears gloves to keep their scent from interfering with the imprinting process. We are asked not to wear white, as the hatchlings may mistake the bright white clothing as the sun and get disoriented, heading towards the white clothing instead of towards the sea where the sun is rising. We are also asked not to bring any food, as that may attract predators, like coyotes and seagulls, which prey on hatchlings.

Kemp's ridley sea turtles are the only species that nest in the day. The females lay 50 to 100 eggs in a clutch. And in the late spring to summer season, the females may lay two to three times, then take the following year off. When the turtles lay their eggs, they enter a trance state, where they tune everything out. This is the time the scientists take measurements and make observations of the turtle. It is also when the turtle is most vulnerable, especially since they like to nest in the tracks of soft sand made by vehicles. And they are prone to get run over because they blend well with the sand and they won't get out of the way. That's why teams patrol the beaches to spot and protect nesting or injured or ill turtles.

As with other reptiles, the temperature in the nest determines the sex of the hatchlings. Higher temperatures lead to more females. So the eggs near the top, close to feel the heat of the sun, are females. The eggs towards the bottom turn out to be males.

Once they grow up to be adults, the females will return to lay their eggs. But the males will live our their lives at sea.

The team knows that the hatchlings are ready to hatch out of their shells by their activity. In their special sand incubators, the hatchlings start to move towards the surface, from a depth of a foot or so. The first hatchers create enough movement to cause the sand to form a divet, a hole, in the top of the sand. That signals that the frenzy, the act of crawling out the sand and towards the sea will begin soon, at the next sunrise. And since these are reptiles, cold blooded--unable to regulate their own body temperature, they need the warmth of the sun and a little time to get moving, and some late hatchers take a bit more time to wake up and warm up to get moving.

These are the little ones the park rangers bring around to show us. And after a little time warming up in the ranger's hands, the hatchling is ready to join their siblings all ready in or headed towards the sea. Then they are released and guarded as they make their way toward the waters of the Gulf of Mexico.

Please, No Flash Photography. The bright light disorients the hatchlings and ruins the imprinting process. Cute little babies, aren't they?

It takes 10 to 12 years for the baby hatchlings to mature. So, it will be at least 10 long years before we see the females from this clutch return to nest on these shores. Let's hope these babies all survive and thrive to adulthood.

Have a safe journey, little hatchlings! Y'all come back, now, ya hear!?!