By Mary Pringle for Island Eye News

A vial containing the DNA sample for Nest #23 on the Isle of Palms which was laid at Summer Dunes Lane on June 16.

You may be aware that this is the 8th nesting season that the Island Turtle Team has taken DNA samples from every nest laid on our islands. This is a huge project involving all of the loggerhead nests in North and South Carolina and Georgia. Recently Dr. Brian Shamblin of the University of Georgia has expanded it to include some of the nests in Florida where many thousands of loggerhead nests are laid each year. It takes multiple years of funding to gather these results.

The purpose of this study is not only to get an accurate picture of the population of nesting loggerheads on the Atlantic Coast but also to find out:

How many clutches of eggs does each nesting female lay in a year?

Is she nesting on more than one beach?

How far apart are her nests?

How many turtles are nesting in more than one state?

Most individual females do not nest every year. How often does each turtle nest: every two years, three years, four or more years?

How precisely does a daughter return to her hatching site to lay her eggs?

Results have shown fascinating things about our nesting females. It takes 25-30 years for a female loggerhead to mature and start laying eggs. This study has shown that there is a grandmother in the Cape Romain National Wildlife Refuge near McClellanville who is still laying nests. She has 14 daughters currently nesting and even has 4 granddaughters nesting! How amazing is that?

In one of the earlier years of the study there was a loggerhead who nested on the Isle of Palms, then two weeks later laid eggs on Hatteras Island in NC, and two weeks after that laid a third nest on Cumberland Island in Georgia. So the information we formerly told people about turtles always returning to the beach where they were hatched is not necessarily true although some of them seem to do so. The study is also showing that individual females usually nest 4 to 6 times in a season at 2 week intervals but then will rest and restore their body condition and skip a year or even two before coming back to lay eggs again. With over 100 eggs each time, this is quite a feat.

We are excited to see the DNA results from the first two nests of 2017. Nest #1 at 56th Avenue, the earliest in NC, SC, or GA, was a faithful IOP nester. She laid eggs here 3 times in 2012. In 2014 she was a busy girl with 4 nests on the IOP and one on Dewees Island.

She did not lay eggs in 2013, 2015 or 2016 but is now back. The mother of our Nest #2, who laid eggs up against the pool fencing at 510 Ocean Blvd, is not as faithful to our island. She nested in 2015, twice in North Carolina and once on Capers Island, but took last season off. It will be interesting to see in our future samples of one eggshell from each of our nests if these two turtles lay more than once on our beaches or where else they go to nest.

See the original post here:
Genetics Research Update - Island Eye News

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