Sea turtles are one of the greatest wonders of nature with human beings trying for centuries now to understand these ancient creatures. They are not the most powerful, nor the most beautiful, but the sight of one always makes people stop and wonder. They have been around longer than human beings but we are now the greatest threat to their survival. That doesn’t mean human beings have abandoned turtles though, there are lots of conservation projects for these poor creatures all over the world. However, while amazed by them, there is still so much we don’t know about them. Here is a look at some interesting facts you probably didn’t know about sea turtles.
They Have A Compass In Their Heads
Turtles are sensitive to the earth’s magnetic field as they have an inbuilt GPS, thanks to special receptors located in their brain. They can determine their exact location in relation to the earth’s magnetic field, hence ability to locate favourable feeding grounds and return back to their natal nesting sites(home) to lay eggs at the exact place they were hatched. This special feature enables turtles to migrate thousands of miles and still locate their nesting sites after half a century. It is a mystery that is yet to be fully understood by science.
Their Sex Is Determined By Temperature
Turtles leave their nests as soon as they lay their eggs never to see their babies leave alone incubate their nest. The temperature of the nest is solely dependent on the temperature of the surrounding beach or land. When the temperature of incubation 87.8 degrees F, the hatchlings will be female, and 81.86 Degrees F, male. In between will result in both males and females. Global warming has resulted in more female hatchlings than males, which puts their survival at risk
Turtles Can Drown
Sea turtles do not have gills. Therefore, just like whales and dolphins, they have to surface to take a breath of air periodically. Despite the fact that they can actually slow their heart rate up to 9 times, underwater, reducing the rate of oxygen pumping in blood, turtles can actually drown when trapped in fish shells, predator’s mouths or when females get overweighed by many males trying to mate her at the same time. Diseases like papillomavirus can also hinder their ability to surface.
6 out of the 7species of Sea Turtles in existence are endangered.
Of the 7 known species of turtles, six are listed by the CITIEs as vulnerable, endangered and critically endangered. The green turtle is the only herbivorous marine turtle, responsible for keeping check of the grass hence the general health of coral gardens. They are also classified as endangered.
Hawksbill turtles have a shiny beautiful serrated shell, that makes them a target for the black market. They are often hunted and shells removed, used to make ornamentals and combs. This type of turtle species is unique and vital in the marine world as it is the only species of turtles that can consume toxic sponges and not be affected by their toxicity. Coastal Urban Development and tourism have diverse effects on the number of marine turtles as there is increased human activities both on the beach and overfishing to serve the growing industry.
Some Turtles Can Freeze Without Dying
When a sea turtle is exposed to cold water for a prolonged period of time, they exhibit a hypothermic reaction called, Cold Stunning. Remember that sea turtles are ectothermic- they are not able to regulate their body temperature so cold water becomes dangerous.
Despite this threat, there is one species called western painted turtle that can freeze solid, breath through its butt and extremely slow down its metabolism. While frozen, the turtle becomes a block of ice that can shatter or crack, but if none of these happens, it will just that and be fine when the cold snap is over.
Only 1 in 1000 Hatchlings Survive
The reason why turtles lay more than 100 eggs per nest and quite a good number of females lay at the same time I to increase the hatchlings chances of survival. On a successful nesting activity at a nesting site, thousands of hatchlings make their way to the ocean but face a lot of predation from birds and stray dogs on the beach as well as crabs from holes beneath. An estimation has it that only 1 in 1000 survives to adulthood.
A new baby turtle is merely 10 cm long but has a great speed, inborn instincts to escape predation. Even after reaching the ocean, these babies have a lifetime of migration facing predation, being trapped in fishing nets and drowning.
They Can Live For Over A Century
While most sea turtles have an average lifespan of 80 years, some turtles can actually live up to 100 years and those kept as pets even more than a century. Their slow metabolism and a diet of jellyfish gives them an upper hand for a longer and healthier life. Tortoises, their land relatives have been known to survive up to 150 years in captivity.
Their Shell Is Also Their Rib Cage
The outer shell of a turtle is made up of the same material as human fingernails called keratin. Keratin is the most abundant form of protein found in living organisms. This hardshell is not found in soft-shelled species like leatherback turtles. The outer shell is fused with their ribcage, having ribs stretched forming broader ribs than joining together to form a protective layer. The lower ribs join to form the Plastron, that covers the turtle from beneath. Each pattern of a turtle shell and the head is unique to the individual just like human fingerprints
They Survived The Dinosaur Extinction
They are among the oldest species on the planet, around the same age as the dinosaurs. With the oldest sea turtles dating back to 220 million years ago, these amazing creatures existed and survived the mass extinction that saw the whole population of dinosaurs wiped out. Their ability to feed, swim and hold their breath underwater has enabled their survival for millions of years.
Some Can Last 30 Minutes Without Breathing
Time spent underwater by sea turtles varies according to species. Some like the loggerhead sea turtle have been found to spend more than 8 hours underwater. Turtles have the ability to sleep for 4-7 hours and up to 10 hours while hibernating underwater without drowning. It is only when caught in fishing nets and other traps used by fishermen that they fail to surface to breath hence dying if they are not rescued.