Mainly at night. Leatherbacks nest from early March through mid-June typically, but this species accounts for less than 1% of the nests we get in Broward County. Loggerheads are our biggest nester and tend to nest from April through early September, with peak months being June and July. Greens nest from late May through early September, with alternating extreme high and low nesting seasons.
Depends on the species. Average for loggerheads and greens are about 100-110 ping-pong ball sized eggs. Leatherbacks lay about 90 tennis ball sized eggs. All sea turtle eggs are leathery and somewhat soft so they dent instead of breaking.
Adult loggerheads average 300-350 lbs. Greens can way up to 500 lbs. Leatherbacks can get up to 1500 lbs (the biggest being recorded at 2000 lbs).
There has not been a turtle followed from emergence to natural death. Onset of sexual maturity is also species dependent, but is typically around 20-25 years.
Loggerheads and green eggs hatch in about 45-55 days. Leatherback eggs take a bit longer, reaching upwards of 70-80 days, sometimes longer.
A natural or in situ nest will have a hatching success rate of 80-100%, while a relocated nest will have a hatching success rate of 60-70%. Overall, only one in 1,000 to 10,000 sea turtles will live to maturity. Major predators after nest emergence include birds, fish, crabs, and foxes.
As hatchlings, you can't tell by looking. As adults, males have a much longer tail than females. Sand temperature affects gender: 29.6 degrees Celcius during the middle third of incubation will produce a 50:50 gender ratio. A couple of degrees higher will produce all females and a couple of degrees cooler will produce all males.
Yes, that seems to be the case. An individual turtle will nest within 5 miles to 35 miles, on average, of where they hatched from and/or nested in the past, based on tagging studies. There's also evidence that the hatchlings can detect variations in the earth's magnetic field and that's how they navigate back.
Yes, an individual loggerhead or green female will nest 2-5 times per year, typically at 2-3 week intervals. Leatherbacks will nest 7-10 times per year at 10 day intervals (approximately). She will not nest every year however, but rather every other year or third year. This will depend on how well they eat during the year/non-nesting season.