Sea Turtle Nesting Season: Boom And Bust
According to the Florida FWC, the number of sea turtle nests statewide are at all-time record highs. In fact, the number of “green” sea turtle nests locally have been substantially higher this year. While FWC reported 21 green turtle nests for all of Charlotte County in 2018, our own Don Pedro/Knight Island Sea Turtle Patrol has tallied 140 green nests as of 7/31. Although this is great news for turtle season overall, it does not necessarily reflect how many baby turtles will actually survive.
Here – In addition to the typical problems of nest wash-overs and root incursion, ghost crabs, fire ants and seabirds – turtle nests are also being breached by highly destructive local predators: coyotes and armadillos.
A relatively new intruder
Coyote tracks have been observed on the beach in the area just north of Don Pedro State Park since 2013. Soon after, turtle nests were discovered dug up with eggshells strewn about the opening. Volunteers began securing screens over the nests to protect them from the coyote, only to find armadillos burrowing under the screens to attack the nests.
This year, there have been numerous confirmed coyote sightings on Don Pedro Island by residents on Bocilla Dr., the north and south ends of Kettle Harbor Dr., by the Kosinski Bridge, and along the beach roads, to name a few. County staff from the Dept. of Natural Resources confirms that small tracks have also been found, indicating the presence of a juvenile.
In 2015, residents and Sea Turtle Patrol volunteers Kjell Plotkin and Barbara DeYulio applied for a grant from the Florida Sea Turtle Grants Program, administered by the non-profit Sea Turtle Conservancy. PIE hosted the grant proposal through their Wildlife and Habitat Preservation Program. [Kjell was President of WHPP at the time] The grant project consisted of securing the professional services of a trapper to track, set traps and remove captured armadillos. The Sea Turtle Conservancy is funded by a portion of revenues from Florida's Sea Turtle Specialty License Plate.
According to the proposal, “a dramatic number of marine turtle nests on Don Pedro and Knight islands were destroyed in 2014 and 2015 by predators. For example, in two monitored zones (approximately one mile of beach), 100% of the nests were predated in 2015; in 2014 90% of the nests were predated”. The grant, however, was not funded at that time.
Each year following, the predator population has grown in tandem with the rising number of turtle nests.
Current depredation rates
Recent data provided by several turtle patrol members clearly indicates that predation of turtle nests is a serious problem.
Judy Kelley works the north end of the Island from Access 12 to the spit at Stump Pass. “Coyote prints are seen most mornings. All my predations except for one have been by coyotes. Only one by an armadillo,” she tells us. For her, “placing a screen after a predation has prevented coyotes & armadillos from coming back to the same nest”. Through 7/31, Judy has tracked 105 loggerhead nests. Of these, 25 had been predated (8 of those were totally destroyed). Of the 22 green nests, 4 had been partially predated.
Judy noted a few unusual events this year: a green was seen finishing up a laid nest on her morning patrol. A loggerhead laid her nest around 7:00 one evening. A Kemp’s Ridley sea turtle, rarely seen on this coast, laid her nest mid-day. Unfortunately, the nest didn’t hatch due to water inundation.
Barbara DeYulio, Lindsay Yates and Sally B. Johnson walk the turtle beat south of the Resort to Beach Place. Last month Barbara reported that in her area, 3 out of the 43 green nests had been dug into. And out of 110 loggerhead nests, 30 had been attacked.
The next stretch of the beach is covered by Jayne Kebe. According to Jayne, “I collect data with Valerie Guenther and Ray and Marie Smith on Zones 5-7, which go from the south end of Beach Place (start of Zone 5) to the Colony pool (end of zone 7). We’ve had 160 loggerheads and 41 greens to date. My predation is running now at about 67%. Not all of these nests are totally destroyed. We have been screening nests when supplies are available to try and prevent further destruction. We’ll see how successful that is.” She goes on to say that “I would say there is maybe equal predation of armadillo and coyote. The armadillos are willing to work harder to get access through the screens and are occasionally successful.”
The heaviest load is in zone 9, from the Colony pool south to the State Park, which is monitored by volunteer Pat Gordon. ”As of 7/31, there were 34 green nests, 16 of which have already been predated, and 172 loggerhead nests. A total of 23 nests had hatched, two of which were green nests. One of the green nests was predated, and as a result only 15 turtle eggs hatched out of a total 111 eggs in the nest. Of the 23 total hatched nests, only 6 were not predated, resulting in a 74% predation rate for hatched nests as of the end of July.” Her concern now is that, as nesting slows, the predators will decimate the remaining nests through the end of season.
What’s being done and is it enough?
With the odds stacked so heavily against them, the rule of thumb is that roughly one in a thousand hatchlings will survive to adulthood (15-25 years). The increase in predator activity, specifically coyotes and armadillos, has the potential of reducing even further the likelihood of their survival.
“We must keep in mind that Marine turtles have survived predation since the dinosaurs” says Brenda Bossman, the state permit holder overseeing sea turtle patrols on Knight and Don Pedro islands. “Remember the raccoon predation years ago? We don't have them now that we have coyotes. It's a trade-off” she tells us. “But we didn't have armadillos then, either. The coyotes alone wouldn't be as bad.”
At this time, the County has contracted with USDA Wildlife to track and trap the coyotes in the State Park, but that does not address the armadillo problem. Valerie Guenther notes that “The problem is that the State and the County won't trap on private property, so they trap in the park and sometimes in the preserve land by Sabal Palm Pointe.” However, she notes “Armadillos live mostly in and around property on North and South Gulf Blvd - especially in the Colony.”
Don Pedro & Knight islands are not alone in this dilemma. On July 19, 2019, Coastal Wildlife Club posted on their Facebook page “Heading for record Green Sea Turtle nesting on Manasota Key but Loggerhead nesting has slowed down significantly. Heavy coyote depredation hitting nests up and down the key.”
Due to the need for access to private property, a community-based organized effort would be required to reduce the impact of predators – particularly the armadillos – on sea turtle nesting here on the Island. Until then, homeowners can be mindful of the regulations in effect during turtle season. These include: