Triangulating Turtle Eggs


SCA Intern Jeffrey Sommer Keeps Tabs on the Hatchlings at Canaveral National Seashore

Turtle Conservation isn’t all starlit, beachside fun and games folks. In fact a good chunk of the work I do keeping sea turtles off the extinction list happens inside the library of Canaveral National Seashore headquarters. In order to prove that sea turtle conservation is working and worthwhile, we need to document every single turtle event on the beach, from nesting to standing. It’s not as easy as opening up a tablet and inputting all the information on a spreadsheet, right there on the beach. First off it would take too long, and secondly sand+water+weather+bugs = bad for technology. This means we sea turtle lovers have to return to civilization every few days to upload and sort through our data, which isn’t a simple or straightforward process. Upping the stakes is the fact that all this data is auditable in perpetuity, so we have to get it right every time. It isn’t all that difficult once you know what to do, but I’ll get back to this subject a bit later.

First, though, Tuesday, August 12, was a beautiful day. It started out, for me at least, with a black sky spotted with stars. From the beach the Milky Way was vivid against the stark, sparkling sky. Soon, however, the sun came along and stripped away the beauty of the night, bringing out swarming insects–mosquitos and dragonflies–as well as hot, energy sapping rays. The worst doesn’t happen until 10:00 or 10:30, though, so at least we got a few hours of star-glow transitioning to gentle, oblique sunlight. Caroline and I hit the beach around 5:30, just early enough to need headlights to safely navigate our ATVs. Just as that aforementioned hot ball of fire was starting to peak above the horizon, we spotted our fellow turtlers hanging out oceanside with quite an impressive guest.

That’s right, you guessed it! A little lady loggerhead functioning on college student time, aka running behind schedule. We arrived on scene just as she was finishing up her nest. We got to see her complete the egg-burial process, then strut her stuff down the beach like it was some kind of catwalk (though it may be more like the charge of the light brigade for her offspring when they hatch!). As soon as she left we processed her nest–checked it for eggs, screened it, and marked it. The end result looked something like this! 

All that information on the stake tells us a few things. First it indicates what beach the turtle settled on, next it tells us where this nest falls in the count for the season, followed by species, then beach location, date, and the moniker of the person/people who reported the nest. This is all essential for filling out government paperwork and conservation/management databases. It’s also important for the sea turtle researchers who use nesting data from Canaveral for a multitude of projects. All this and more is reported in the field data sheets, which are then transcribed into Canaveral’s database to build a record of false crawls and nesting. The picture becomes complete, however, only when we’ve combined this data with hatch rates for all of the different turtle species.

This is done in part through a white staking process known as triangulation. In order to have a statistically significant sample of turtle hatch rates we excavate every 20th

Loggerhead, every fifth Green, and all Leatherbacks and Kemp’s Ridleys. Once the nests that have to be excavated are determined, Caroline and I head out on the beach and use the location information to locate them. We then replace the normal yellow stake with a white stake, copying down all the information from one to the other. Lastly, we install two more white stakes up in the dunes, which help us locate the nest if the main stake disappears for some reason, (i.e. a large storm). This way, when hatch time rolls around, all the nests we need to monitor are triple white-staked for easy locating. Determining hatch rates is a time and energy intensive process, but it’s also fun and rewarding!