Coastal Wildlife - FY 2021-22 SCCF Annual Report

Coastal Wildlife

Shorebird Monitoring: 20 Years of Data

2022 marks the 20th anniversary of SCCF’s shorebird monitoring program. In that time, staff, interns, and volunteers have located and monitored 337 snowy plover nests and observed 143 chicks survive to fledging age. In response to a statewide effort to better understand the nesting population of snowy plovers (Charadrius nivosus) in Florida, Sanibel was identified as an important nesting location. Over the years, the program has expanded to include year-round surveys of migratory, non-breeding shorebirds and other beach-nesting birds including least terns (Sternula antillarum) and Wilson's plovers (Charadrius wilsonia). As part of the Florida Shorebird Alliance, SCCF also works with partner agencies to monitor and protect shorebirds on Bunche Beach and North Captiva.

In the 2022 season, snowy plovers initiated nests earlier than in the past several years. There were no nesting attempts by least terns or Wilson’s plovers on Sanibel or Captiva. For the fourth consecutive year, banded male snowy plover White/Blue fledged one chick. A total of five nesting pairs had nine nesting attempts. Of those, two failed and seven hatched. One nest was depredated by crows, and another was washed over during a tropical weather event in early June. Of the 17 hatched chicks, five survived to fledging age but only two were confirmed fledged. We remain hopeful that we will get reports of all banded chicks in the future.

Sea Turtles: Monitoring

Our sea turtle nesting season started April 15, kicking off seven months of monitoring by our 86 volunteers and eight staff. The first nest of the season was discovered on April 27 by intern Carley Nolan. In total, 768 loggerhead (Caretta caretta) nests were reported, which is a slight drop from 2021’s 904. Although this was predicted to be a lower year for green turtles, our team documented 18 nests. We are happy to report a successful hatching season, with more than 35,500 hatchlings emerging from nests on Sanibel and Captiva.

Long-Term Impacts of Red Tide

The 2017–2019 harmful algal bloom in Southwest Florida resulted in the most sea turtle deaths ever attributed to a single red tide event. Over the last three years, our sea turtle team has been leading an in-depth project to learn more about the longterm effects of this catastrophic bloom. This project is the largest in scope of its kind, with samples collected from 402 nesting females, 1,593 unhatched eggs, and 285 dead hatchlings. Our data indicate that the nesting females did not have abnormally high brevetoxin concentrations in the years following a bloom. However, many of the hatchlings sampled in 2020 and 2021 had very high toxin loads, suggesting the nesting females are storing these toxins, likely in fat, and transferring them to their hatchlings. Results on health and immune function are expected soon. Preliminary analyses suggest that hatching success was not impacted by the toxins in the hatchlings.

Nesting Variables

Since 2018, we’ve been monitoring the temperature, moisture, and water exposure in loggerhead nests to answer questions about how the incubation environment affects clutch viability and hatchling sex ratios. Understanding how changes in beach characteristics could be adversely altering embryonic development and hatchling production has implications concerning future generations of sea turtles. For example, our research has identified that after the 2021 beach renourishment project, the elevation, temperature, and groundwater/tidal exposure for nests on Captiva have all changed, with statistically significant to possible impacts of these variables on emergence success. Information from these studies also contributes to long-term datasets that can be used to monitor trends in temperature and moisture.

Our Coastal Wildlife team also contributes to these collaborative projects:

• In partnership with Audubon Florida’s Eagle Watch program, SCCF staff and a team of volunteers monitored 13 nest structures. Of the eight nests used by bald eagles (Haliaeetus leucocephalus) this year, five failed and three successfully fledged one eaglet each this year.

• Swallow-tailed kite (Elanoides forficatus) nests are monitored by volunteers and staff in partnership with the City of Sanibel and the Avian Research Conservation Institute.

• The International Osprey Foundation funded a project for SCCF to investigate impacts of red tide events on food provisioning in ospreys (Pandion haliaetus).

• A statewide sea turtle disease assessment survey for viruses associated with fibropapillomatosis and lung-eye-trachea disease conducted by Drs. Justin Perrault (Loggerhead Marinelife Center) and Annie Page-Karjian (Florida Atlantic University).

• The relatedness among nesting sea turtles and the tracking of offsite nesting through the creation of individual genetic tags by Dr. Brian Shamblin (University of Georgia).

• A tool that allows researchers to identify the area where each female sea turtle forages and resides led by Dr. Simona Ceriani (Florida Fish and Wildlife Research Institute).

• The orientation response of sea turtle hatchlings to physical cues on nesting beaches through an evaluation by Dr. Tomo Hirama (Florida Fish and Wildlife Conservation Commission).

Adopt-A-Beach Heroes!

Many thanks to the neighborhoods and condos that have come together to foster safe turtle nesting on their beaches.

Angler's Key

Chateaux Sur Mer

Clamshell

Gulf Pines/Gulf Shores

Gulf Ridge

Gulfside Place

On Island

Tamarind

The Village in Captiva

West Gulf Drive