Tuesday, June 09, 2009

Tracking turtles - False Crawls


Some of my young blog readers have been curious about my turtle patrolling duties, so here are recent photos I've taken, along with information for my younger friends.

This is a photo of a false crawl I found this past Sunday morning on the beach within the Ft. Pickens section of the Gulf Islands National Seashore. A false crawl is when a sea turtle comes ashore but for some reason gets startled or unhappy with the area and returns to the sea without making a nest or laying her eggs.

This sea turtle did not come very far ashore - only 20 ft. - before turning back. You can see that her tracks go over the tracks of the patrol vehicle from the day before, so I know they are new.

The false crawl was very near the old Ranger's house. You wouldn't think there would be any lights or activity to frighten the turtle away from this spot since the house is unoccupied and the park is closed at night, but we do know that light pollution, also known as urban glow or sky glow, can be enough to confuse them. This is why we ask people to please turn out their lights and close their curtains during the nesting season.

When sea turtles leave the water to lay their eggs, instinct guides them toward dark areas which would normally be land, and away from light which would normally be the moon shining on water. As they come ashore, if they see glowing lights in the distance, they may say "Uh oh, wrong way," and sadly head back out to sea without nesting.

Some people say, "My neighbors keep their lights on, so what good does it do to turn mine off?" The reason is that everyone who leaves their lights on contributes in some small way to sky glow. Changes that you make, even turning out a few lights or your outside lights, can be very helpful.

Here is a closer photo where you can see the sea turtle's flipper marks in the sand as she turned around. Can you imagine how much effort it takes for a 200+ lb turtle to drag herself ashore with her flippers? So graceful and buoyant in the water, they are slow and cumbersome on land.

This photo shows you how we determine what kind of sea turtle tracks we're looking at. Notice that the flipper tracks are alternating - sort of like when you look at your own footprints in the sand. The fact that they are alternating, combined with the width of the tracks (36"), tells me this is a loggerhead sea turtle.

Sea turtle trivia: Did you know that 80% of all loggerhead sea turtles in the United States can be found in Florida?


Seadog said...

are the turtles hatching yet or is it too early ?

molly said...

Poor tuttle, how if they couldnt find a suitable place to hatch their eggs? Hope they found one by now.

Barrier Island Girl said...

Hey Seadog,

The turtles start nesting around the first of May. Gestation is around 60 days, depending somewhat on temps. A nest layed on May 1 would emerge around July 1.

We seem to be behind this year, unfortunately. I'm ready to find some nests!

Are you back home now or still on the beach!


Barrier Island Girl said...

Hi Molly,

Individual sea turtles will come ashore for nesting several times each year, but then they go a year or possibly two before going through another nesting cycle! So some of our nests from last year came ashore more than once to nest, but it will be another year or two before they nest again.

Hopefully the turtle who did the false crawl on Sunday will come ashore again soon. Perhaps within days. These poor creatures are endangered and the survival rate to maturity is very low. A generous estimation is that 1 out of every 10,000 sea turtle hatchlings will survive til maturity. They definitely need our help.

Thank you so much for your comment!


Christie said...

Thanks so much for carrying on the turtle information. Although I never met Turtle Girl, I followed her blog and miss her terribly. I've been fascinated with turtles ever since I was a little girl and was able to go on a midnight walk hosted by a park ranger. I hope one day to be able to see a turtle release. Thanks for all your beautiful pictures - you give me my "beach fix". My husband and I own a condo in Emerald Isle and like to get down as often as possible.

Seadog said...

still on the beach til saturday, at concert last night very nice !!

Barrier Island Girl said...

Hi Christie,

Thank you so much for the kind comments. I still miss Kirsten so much. She taught me a lot and it's difficult to deal with sometimes, knowing just how big that loss was - not just friendship, but someone with so much knowledge and compassion.

If you would like to go to my profile and send me an e-mail, I'll let you know if there is a scheduled release later this year. Sometimes they do that with Kemp's ridleys. Unfortunately we are quite a bit behind in nests this year. :-(


Unknown said...

Great info