There are seven known species of sea turtles on the globe and of them, the hawkbill has the shortest life expectancy, the 30-50 years mentioned earlier. The lovely green sea turtle has the longest, on averaging living to be a ripe old 80 (plus) years. Both the largest and the smallest (the leatherback and the Kemp's ridley, respectively) live to the age of 45-50 years, on average.
The early life of the sea turtle is a bit precarious and not many survive the open ocean phase which lasts between two and ten years. This period in their lives is often referred to as "the lost years" because they're movements are hard to track during this stage. Turtles grow up slowly; taking between 15 and 50 years to become reproductively mature. Like birds and fish, sea turtles rely on the magnetic field of the planet to return to their place of birth. Their migrations can be lengthy. In 2008, a leatherback was tracked traveling 12,774 miles from Indonesia to Oregon. Females have been known to nest until the age of 80.
This is all pretty amazing stuff, right? But, wait! There's more.
1. Sea Turtles are considered reptiles, meaning they are cold-blooded animals. They lay eggs and have scales, or did at some point during their evolution, breathe through lungs, and have a 3 or 4-chambered heart
2. Sea Turtles lay their eggs on land. Amazingly, female sea turtles return to the same beach where they were born to lay their own eggs.
3. A sea turtles gender is determined by the temperature of the nest. Sea turtle eggs incubate for 45-70 days before hatching. The length of incubation time is determined by the temperature of the sand where the eggs are laid. Eggs more quickly in warmer sand and with less rain. Cooler temperatures also determine the gender and cooler sand temps usually produce male sea turtles. If you think about it, this can be greatly impacted by Global Warming. Even the position of the eggs can be a determining factor when it comes to gender. The center of the nest is usually warmer so the chances are increased that the center egg will produce a female sea turtle. The outer eggs will more likely be male.
4. Sea Turtles are endangered. Of the seven sea turtle species, six of them (all but the flatback) exist in the United States. And all of them are endangered. Threats include man, loss of habitat, harvesting them or their eggs for food, bycatch in fishing gear, climate change, the ingesting of marine debris (plastic straws???), and boat traffic. With a list that long of things that threaten their existence, what chance do these gorgeous and fascinating critters have?
5. The first sea turtles lived about 220 million years ago. Sea turtles have been around for a long time in evolutionary history. The first turtle-like animals are thought to have lived about 260 million years ago, and odontochelys, the first marine turtle, is thought to have lived about 220 million years ago. Unlike modern turtles, odontochelys had teeth.
The title of oldest living sea turtle remains unclaimed. Determining how long sea turtles live can be difficult for they often outlive the duration of most studies. When sea turtles are tagged, satellite data transmission typically lasts just between six and 24 months. So that's certainly not much help.
I really enjoyed learning about sea turtles and I hope you did, too. Please do what you can to help preserve these amazing reptiles. At the very least, stop using plastic straws.
Tomorrow is Wednesday and that, of course, means a visit from Dharma Frog. Please come back and learn what the wise old frog has to teach me this week. Until then,
Kennedy, Jennifer. "10 Fascinating Facts About Sea Turtles." ThoughtCo, Oct. 19, 2018, thoughtco.com/fun-facts-about-sea-turtles-2291407.