The nesting season in Broward County begins in early March with leatherbacks, loggerheads in April and then greens in the end of May (see below). However, leatherbacks are less predictable and can nest as early as February. Nesting continues through the end of September, with the peak season for loggerheads being the end of June and the beginning of July
Leatherback, Loggerhead & Green Sea Turtle Nesting Per Day for the 2015 Season
If undisturbed, the females emerge from the ocean crawling up the beach where they dig an egg chamber cavity that is essentially a hole. After resting they deposit approximately 100 golf-ball size eggs (for loggerheads). Then the back flippers gently cover the eggs with sand using it to camouflage the nest site. Lastly, they leave to reenter the water, never meeting their young.
A single female may nest several times during a season and then not again for one or two years. Approximately half of all emergences result in a female crawling on the beach for long distances and reentering the water without digging a nest (see image). These are called "false crawls" and usually occur because the turtle was disturbed or it could not find a suitable nest site. The crawl tracks, resembling tractor tire tracks, are always made by female sea turtles. Male sea turtles never leave the ocean.
Sea Turtle Nest Sea Turtle False Crawl
Broward County Nesting Survey Data by Species Showing an Overall Increasing Trend
Incubation of the nests in Broward County can take approximately 48-55 days. The eggs deposited green emerging from nest the chambers are normally left to incubate in situ or naturally. Nests that are at risk of human impact are relocated to a safer area of the beach or outfitted with a cage. After incubation, the hatchlings emerge from the nest en masse and, using various environmental and inherited cues, quickly migrate to the water's edge. If artificial lights are illuminating the beach, the hatchlings will be disoriented, travel in the wrong direction, wasting energy and possibly never making it to the water (see lighting section for more information).
Loggerhead hatchlings left, green hatchling right
Once in the water the hatchlings find sargassum seaweed patches which they eat and use as shelter. These seaweed patches can be found floating in the Gulf Stream current off of Florida (part of the North Atlantic Gyre that flows clockwise up the U.S. coast and eventually past the Azores). A paper recently published by Mansfield et al. 2012, found that a number of turtles dropped out of these outer currents into the center of the gyre and accumulated in the sargassum seaweed. Additionally this research revealed that the seaweed patches may keep these cold-blooded reptiles warm likely assisting with their growth. It was only very recently that researchers were able to track where the hatchlings spent their time during what was previously called “The Lost Years.” After 20 years or so only the female turtles will return to the beach!