Sea turtles are one of nature’s greatest wonders, and humans have been trying to understand these ancient creatures for centuries. They’re not the most powerful or the most beautiful, but the sight of one always makes people stop and marvel. They’ve been around longer than humans, but we’re currently the biggest threat to their survival. That doesn’t mean humans have given up on turtles, as there are many conservation projects around the world to save these poor creatures. However, despite their fascination, there’s still so much we don’t know about them. Here are some interesting facts about sea turtles that you probably didn’t know.
They have a compass in their head.
Turtles are sensitive to the Earth's magnetic field because they have a built-in GPS thanks to special receptors located in their brains. They can determine their exact location in relation to the Earth's magnetic field, hence the ability to find favorable feeding sites and return back to their original nesting sites (home) to lay their eggs in the exact spot where they hatched. This special feature allows turtles to migrate thousands of miles and still find their nesting sites half a century later. It's a mystery that science has yet to fully understand.
Their gender is determined by temperature.
Turtles leave their nests as soon as they lay their eggs and never see their babies sitting alone in the nest. The temperature of the nest depends solely on the temperature of the surrounding beach or ground. At an incubation temperature of 87.8 degrees Fahrenheit, the hatchlings will be females, and at 81.86 degrees Fahrenheit, the hatchlings will be males. In between, both males and females will emerge. Global warming has caused females to hatch outnumber males, threatening their survival.
Turtles can drown
Sea turtles don't have gills. So, like whales and dolphins, they must periodically surface to breathe. Although they can slow their heart rate up to 9 times slower underwater, which slows the rate at which oxygen is pumped into their blood, turtles can drown when trapped in fish shells, in the mouths of predators, or when females outweigh multiple males trying to mate with them at the same time. Diseases such as human papillomavirus can also impede their ability to surface.
6 out of 7 existing species of sea turtles are threatened with extinction.
Of the 7 known turtle species, 6 are listed by CITIE as vulnerable, endangered, and critically endangered. The green turtle is the only herbivorous sea turtle responsible for grass control and therefore the overall health of the coral gardens. They are also classified as endangered.
Hawksbill turtles have shiny, beautifully serrated shells, making them a target for the black market. They are often hunted, shelled, and used to make jewelry and combs. This type of turtle is unique and vital to the marine world, as it is the only turtle species that can consume toxic sponges without being affected by their toxicity. Coastal urban development and tourism have had varying effects on sea turtle numbers, with increased human activity both on the beach and overfishing to service the growing industry.
Some turtles can freeze without dying.
When sea turtles are exposed to cold water for an extended period of time, they undergo a hypothermic response called cold stun. Remember that sea turtles are ectothermic—they cannot regulate their body temperature, so cold water becomes dangerous.
Despite this threat, there is one species called the western painted turtle that can freeze, breathe through its butt, and slow its metabolism extremely. When frozen, the turtle becomes a block of ice that can break or crack, but if neither of those things happen, it will be fine once the cold snap is over.
Only 1 in 1000 cubs survives.
The reason turtles lay over 100 eggs in a single nest, and quite a few females lay at the same time, is to increase the chances of survival of the hatchlings. If a nesting site is successful, thousands of hatchlings make their way to the ocean, but face numerous predators from birds and stray dogs on the beach, as well as crabs from the burrows below. It is estimated that only 1 in 1,000 survive to adulthood.
A newborn turtle is only 10 cm long, but it has great speed and innate instincts that allow it to avoid predators. Even after reaching the ocean, these babies migrate throughout their lives, encountering predators, getting caught in fishing nets and drowning.
They can live for more than a century.
While the average lifespan of most sea turtles is 80 years, some turtles can actually live up to 100 years, and those kept as pets can even live for over a century. Their slow metabolism and diet of jellyfish give them the advantage of living longer, healthier lives. Turtles, their land-based relatives, have been known to live up to 150 years in captivity.
Their shell is also their rib cage.
The outer shell of a turtle is made of the same material as human fingernails, called keratin. Keratin is the most common form of protein found in living organisms. This hard shell is not found in soft-shelled species such as leatherback turtles. The outer shell is fused to their rib cage, with the ribs stretched out to form wider ribs than join together to form a protective layer. The lower ribs join to form a plastron that covers the bottom of the turtle. Each turtle's shell and head pattern is unique to each individual, like a human fingerprint.
They survived the extinction of the dinosaurs
They are one of the oldest species on the planet, about the same age as dinosaurs. With the oldest sea turtles dating back 220 million years, these amazing creatures survived the mass extinction that wiped out the entire dinosaur population. Their ability to feed, swim, and hold their breath underwater allowed them to survive for millions of years.
Some can go 30 minutes without breathing.
The amount of time sea turtles spend underwater varies by species. Some, such as the loggerhead sea turtle, have been found to spend over 8 hours underwater. Turtles are capable of sleeping for 4-7 hours and hibernating for up to 10 hours underwater without drowning. Only when they become caught in fishing nets and other traps used by fishermen are they unable to surface to breathe and will die if not rescued.
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