Meadow Musings
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Oct. 23, 2009
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Weekly Wrap-Up: Turtle Nest Excavation
October 23, 2009
If you missed my post from last week, this is the season of sea turtle hatching in Hawai'i. So our weekly wrap-up is the story of a turtle nest excavation.
There are 2 main turtles that nest on the Hawaiian islands- the green sea turtle or honu, and the hawksbill turtle, known as 'ea or honu'ea. The females haul out of the water during the months of August and September, usually returning to the same nesting site where they hatched. On average, they lay 180 eggs, which take about 65 days to hatch. The sex of the turtle in the egg is determined by temperature and where the egg is located in the nest. Cooler eggs develop into males, whereas the warmer eggs become females.
The green sea turtles typically nest in the northern sholes of Hawaii, away from the inhabited islands. The hawksbill turtle prefers to nest on Maui and the big island of Hawai'i.
The eggs hatch at night. The baby turtles, averaging about the size of a quarter, have to dig their way out of the nest and then trek down to the ocean. They use the light of the moon to find the ocean, and have to run a gauntlet of lots of animals that are interested in eating them for dinner. These include cats, dogs, crabs, and birds, not to mention bigger fish and sharks in the water. Poor little guys!
The Hawaiian Division of Water Resources counts the number of nests each season, and volunteers keep a "turtle watch" once hatching starts. Then several days after the turtles emerge, the nest is excavated to count the egg total and also rescue any live turtles who couldn't make it out of the nest.
This hawksbill turtle nest had 191 baby turtles come out on Monday night. We didn't get to see it. 
 The indentation in the sand can sometimes indicate that there are still baby turtles in the nest trying to get out.
Of course, before the excavation started, my kids wanted to play in the water.
The excavation started at 5:30.
By the time the DWR guy got to the bottom of the nest, he had dug down 21 1/2". As he digs, he collects the shell remnants to get totals.
Here are the kids looking down into the nest.
They recovered 191 broken shells, three eggs that didn't develop, and one baby that died in the shell. See the full plastic bag with egg pieces in front of her. She is holding the bag with the dead turtle in the shell.
These are the eggs that didn't develop.
Here is BearLover getting a chance to touch a shell piece.
The shell feels almost like crepe paper- they are incredibly thin. It is amazing to think that there are so many piled on top of each other and then buried under the sand.
My kids finished it like they began it- playing in the water again.
The Moon over Maui
(c) 2009 Meadow Musings |
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• Oct. 24, 2009 - Untitled Comment
Tristan
http://ourbusyhomeschool.blogspot.com