It was an ordinary Wednesday afternoon at Sanibel Sea School – a sunny, late winter day in the midst of high season. The teachers were bustling around the campus preparing for class and cleaning up the backyard when one of them heard something a bit strange behind the building. Curious about the rustling coming from the leaf litter, they went to investigate the noise. They discovered that the odd noise was our resident female gopher tortoise plodding around her burrow, and she was not alone! Our teachers were surprised when they saw two tortoises near the burrow, because this species can be quite territorial - they immediately postulated that it must be a mating pair!
Our resident female gopher tortoise (Gopherus polyphemus) peeking at us from her burrow.
Peering through the surfboard racks with binoculars in hand, the teachers watched as the male tortoise tried to pursue the female. Many tortoises use a series of head-bobs and swings to try to get the female’s attention, but in this case the female was unimpressed. Even with no reaction from the female, the male continued to swing his head and approach her a little quicker with every step. After a few courtship shell-nips, the male decided to try his luck at passing on his genes. Alas, the male was a little over-ambitious on his first attempt because the female suddenly charged and flipped the male over onto his carapace – what a show this was turning out to be!
The bottom half of a turtle or tortoise shell is called the plastron. Notice the indented plastron on the male above. This is how we differentiate between a male and female tortoise - the male plastron is indented and the female plastron is flat.
Usually, we try not to interfere with nature, but when gopher tortoises are flipped upside down, they are unable to right themselves and can become stranded. It's a good thing we have a herpetologist on staff, because he was able to gently right the male gopher tortoise.
This was good news for the persistent male. He immediately continued to pursue the female with some more head-bobs and the two successfully mated – right before our eyes!
Tortoises are oviparous, meaning the female will soon deposit 5-15 eggs into the soft sand near her burrow. The eggs will incubate in the sand for about 80-100 days and the tiny tortoises will use their "egg tooth" to break through their shell, beginning their new life on Sanibel Island.
In 2007, The Florida Fish and Wildlife Commission listed gopher tortoises as a threatened species because of their drastic population decline - these tortoises are protected on Sanibel and even have their own management plan to ensure stable populations in the future.
You may have snapped a photo of these road signs during your visit to Sanibel - an important warning to drivers indicating gopher tortoises may be nearby!
At Sanibel Sea School, we have a protected gopher tortoise area to allow a safe place for these tortoises to burrow and plenty of native vegetation to eat. You can help out too by landscaping your backyard with gopher tortoise-friendly vegetation – check out the Sanibel Captiva Conservation Foundation (http://www.sccf.org/) for some great native plant suggestions!
Our summer campers helped create a gopher tortoise garden during Sea Turtle Week last year - we love to protect creatures from the land and sea!