Sea turtles are migratory. Nearly each nesting season STCB attaches a number of small satellite transmitters to breeding turtles in order to track their movements. The information received from the transmitters provides valuable insight into the turtles’ foraging and breeding habits. All current and previously tracked turtles are displayed in the map below.
Since 2003, STCB has tracked 25 adult sea turtles. We now know that sea turtles born on Bonaire live as far as 2500 kilometers away and as close as Los Roques, only 175 kilometers to the east.
Why we track sea turtles…
Throughout their lives, adult sea turtles migrate between their foraging grounds and nesting sites. Bonaire’s breeding turtles return to Bonaire, their place of birth, every two to three years for a period of two to four months. While they are here, we fit a number of them with small satellite transmitters. The turtles then leave on their regular journeys – of hundreds or thousands of kilometers – to return to their feeding grounds.
Identifying sea turtles’ migratory routes and distant foraging grounds aids understanding of the species and provides valuable information in support of strategies for regional conservation.
How we track
We attach a small, non-intrusive satellite transmitter to a sea turtle’s carapace (shell). Every time the turtle surfaces to breathe, the transmitter sends data about the turtle’s location to NOAA satellites.
The accuracy of the location data varies depending on the number of messages received from the transmitter, environmental conditions and relative positions of the transmitter and the satellites. Each transmission is picked up by a receiver on the satellite and is then plotted onto a map.
Since our tracking program began in 2003 we have tracked sea turtle migrations from Bonaire west to the Gulf of Mexico and to the coastal waters of Nicaragua, Honduras and Colombia; north to Cuba, Puerto Rico, the Dominican Republic and the Virgin Islands; and east to Isla de Margarita in Venezuela.
These countries are “range states” of Bonaire’s breeding sea turtles; regions where our turtles spend portions of their lives. Turtles protected on Bonaire may continue to be protected, or they may become vulnerable when they migrate, depending upon the degree of protection afforded by their migration and destination range states.
Previously tracked turtles
In September 2018, green turtle ‘Bonni’ was fitted with a transmitter after she had laid her third nest. ‘Bonni’ laid five nests and attempted to lay a sixth, but was unsuccessful. During her nesting intervals, ‘Bonni’ swam back and forth between Bonaire and Las Aves, which lies about 40 nautical miles east of Bonaire. We had not seen migration behavior like this before and were quite surprised! When ‘Bonni’ finished her nesting season, she swam to Los Roques where she remained until the transmitter stopped working in January 2019.
On the 8th of October of 2012, Anneke the Green Turtle was fitted with a transmitter after she had laid her fourth and final nest on Playa Chikitu, a beach in the Washington Slagbaai National Park. Swimming across the Caribbean Sea, Anneke arrived to Dominican Republic waters in just six days. She continued west along the coast of Haiti eventually heading into Cuban waters. Anneke arrived to her second home on the 7th of December, 61 days and nearly 2,500 kilometers from her first home on Bonaire. Anneke’s feeding grounds lie in the proximities of well-known archipelago, Jardines de la Reina, a highly diverse and healthy marine ecosystem. Diomira Janga was second annual winner of the Great Migration Game with her prediction off the coast of Parque Nacional Desembarco del Granma, Cuba.
This female hawksbill was fitted with a transmitter on Oct. 14, 2011, after she laid her second nest. She nested six times in 70 days. By the time she had laid her last nest, the first nest had hatched, and 118 hatchlings scuttled into the waters off Klein Bonaire. When Jklynn finally left Bonaire, many high school students closely followed her journey on the Internet in the first Great Migration Game. Jklynn swam north across the Caribbean Sea to the southernmost tip of the Dominican Republic. Her transmitter then stopped sending a signal, so nobody was sure whether she had arrived at her foraging grounds. A renewed signal on Jan. 14, 2012, confirmed that she had reached her foraging grounds at Jaragua National Park in the Dominican Republic. The Great Migration Game main prize winner, Keval Bissessar, predicted Jklynn’s foraging grounds within 35 km.
The first turtle tracked in 2011 was very much a surprise to the STCB team. A green turtle was expected to nest at Playa Chikitu, Washington Slagbaai Park when Toyo, a female loggerhead came to lay her nest in the early hours of August 1st. Toyo was already traveling from her breeding/nesting grounds when she felt the need to lay one more nest and found Playa Chikitu. Toyo was tracked to several Venezuelan islands: Las Aves, La Tortuga, La Blanquilla and Los Roques in a looping migration. Unfortunately Toyo’s transmitter signal gave out after 31 days and 1,200 kilometers of travel, placing her just southwest of Los Roques. We cannot confirm this is Toyo’s home foraging ground.
During 2010, transmitters were placed on two nesting hawksbill turtles at Klein Bonaire and one green turtle at Playa Chikitu, Washington Park. These three turtle migrations exemplified the wide-ranging movements of Caribbean sea turtles, as one traveled west, one north and one east from Bonaire.
The final turtle of the 2010 nesting season to be tracked was a female hawksbill named Piffie. She was found nesting at No Name beach, Klein Bonaire on October 7th. Piffie hung around Bonaire to lay one more nest for the season then departed Bonaire waters first to Curacao and then north, travelling right through Tropical Storm Tomas, all the way to Puerto Rico. Finally she arrived on November 23rd to her foraging grounds of Anegada Island, British Virgin Islands. This reef southeast of Anegada, about 840 km from Klein Bonaire, as of the latest transmission on March 6th 2011. Piffie is the first tracked turtle from Bonaire to call the British Virgin Islands home.
On September 20th, Carice, a green turtle nesting at Playa Chikitu, Washington Slagbaai Naitonal Park was fitted with a transmitter. After laying another nest, she departed towards the southeast, past Los Aves, on to reach the Los Roques Archipelago only 175 km from Bonaire. Carice is the second turtle tracked from Bonaire to call the large coral reef formation of Los Roques Archipelago National Park her foraging home (the other was Heit, a hawksbill tracked in 2006). This area is rich in biodiversity with coral reefs, mangroves, and extensive sea grasses. It is also a destination for many migratory birds.
The first tracked turtle of 2010, a hawksbill named ‘Valley’, was fitted with a transmitter on No Name beach, Klein Bonaire, on September 3rd. Valley nested three more times for a total of six nests then departed to the northwest on October 14th, swimming for 36 days to reach reefs and shallow water banks northeast of Honduras. Valley is one of six STCB tracked turtles to reach these same foraging grounds between Honduras and Nicaragua and Jamaica. Located about 1,400 km from Bonaire, this area is a prime refuge for Bonaire and other Caribbean turtles.
Valley’s travel to this area, along with the five STCB turtles before her, has helped draw attention to the nearby threat of turtle fisheries in Nicaraguan waters. Here, some 10,000 green turtles are harvested annually and many hawksbills and loggerheads are taken incidentally. Two other STCB tracked turtles, STINAPA (green) and Wiske (loggerhead) have returned to foraging grounds directly in these Nicaraguan waters.
Named after one of STCB’s longest tenured and most dedicated volunteers, Tina the female hawksbill successfully nested after three “false crawls” in the early hours of September 16th 2009. Tina left Bonaire’s waters immediately, but it appears as if she wasn’t quite sure where to go… Tina first headed east all the way past Caracas, just north of Isla de La Tortuga some 330 km east of Bonaire. Then Tina headed due north for about 400 km, looping around twice before deciding on foraging grounds in the mouth of the Gulf of Venezuela, south of Aruba. Tina’s journey is one that really must be seen on a map to be believed.
The first turtle tracked in 2009 was a female hawksbill named Doris. Her transmitter was attached after she laid her third of five nests for the season. Doris was the first of our Bonaire nesting turtles to head home to Colombian waters. In only 14 days and 768 km Doris reached foraging grounds just off the Salamanca Natural Protected Area, between the Colombian cities of Barranquilla and Santa Marta.
Greggy Girl, a female loggerhead was fitted with a transmitter August 2nd 2008 when she nested on Klein Bonaire. Surprisingly she hung around Bonaire waters for 27 more days with no additional confirmed nests. Finally she departed Bonaire, making her way 740 km, past Los Roques Archipelago (a known foraging ground of Heit and later Carice) to Margarita Island, Venezuela, only 300 kilometers from the Windward island of Grenada.
The 2008 tracking season began the morning of June 24th when a transmitter was attached to Wiske, a female loggerhead. Wiske was encountered by STCB staff SCUBA diving off of Klein Bonaire’s north shore. Wiske departed Bonaire’s water twenty days later, swimming 1,625 kilometers nearly straight to her foraging home waters in Nicaragua – waters that are quite dangerous for turtles as harvesting of green turtles is still legal and the closed season is inadequately enforced. Wiske’s average speed (km/d) was higher than we have ever seen from a Bonaire turtle – an incredible 81 kilometers per day.
The second turtle to be tracked in 2007 was Darwina, a female and only the second green turtle to be tracked from Bonaire (the first was STINAPA in 2004). Darwina left Bonaire south to Venezuela’s coast, then headed north through Las Aves Archipelago, but then incredibly she came back to nest again on August 8th at the same beach she was found on July 25th. Perhaps she didn’t realize she still had a nest to lay! What is even more interesting is after laying the August 8th nest, Darwina took off in the opposite direction all the way to the Yucatan Peninsula, Mexico. Darwina traveled a remarkable 2,930 kilometers on her journey. Darwina’s signal had not stabilized when it stopped transmitting so perhaps she wasn’t quite at her foraging grounds, but even so, this is the farthest a Bonaire turtle has ever been tracked!
Sponsored by and named after the granddaughter of Queen Beatrix, Eloise, a female hawksbills was fit with a transmitter on 13th of July 2007 while nesting on Klein Bonaire. Eloise laid a total of five nests on Klein Bonaire before departing Bonaire waters for her home foraging grounds of Albatross Bank, Jamaica. Her travel speed was at times very fast, surpassing 100 kilometers in a single day. Eloise passed through and forages very close Haitian waters, where she is at risk of being legally harvested.
Heit, a female hawksbill, was found resting on the reef close to her nesting beach at Klein Bonaire. She was brought aboard STCB’s research boat and fitted with a transmitter on July 13th 2006. Heit had already been tagged on Klein Bonaire in 2004. After laying her eggs for the season, Heit traveled to her foraging waters at Los Roques Archipelago, Venezuela – an area rich with coral reefs and seagrass.
The third turtle to be tracked in 2005, was Mariposita, a female hawksbill who nested on Klein Bonaire in the early hours of October 27th. Mariposita was quite small at only 80 centimeters of carapace length, so perhaps this was one of her first nesting seasons. It typically takes anywhere from 15 to 30 years for a hawksbill to reach sexual maturity and they can live to be well over 60. Despite being small Mariposita traveled 1,474 kilometers to Serranilla Bank, Honduras (the same foraging grounds as Extra, Jenni, Albert and Funny before her). She also traveled with the best navigational efficiency to her destination of any tracked turtle from Bonaire.
Fitted with a transmitter on the night of October 13th on Klein Bonaire, Jenni, a female hawksbill turtle departed Bonaire only six days later to the vicinity of Serenilla Bank, an offshore area between Honduras and Jamaica – and an area now obviously important to many Bonaire turtles. Jenni took 1,874 kilometers to arrive very close to where Mariposita would arrive it just a few weeks. Jenni also took two more days to travel there than did Mariposita. This is referred to as navigational efficiency. How sea turtles navigate so well to specific geographic targets is still pretty much a mystery to humans. To make such migrations, the turtle requires both a compass sense for maintaining headings and also a map sense to know where it is in relationship to its goal. Many animals possess diverse compasses based on stars, the position of the sun, patterns of skylight polarization, and the Earth’s magnetic field. Much is still to be learned about the mechanisms that underlie the map sense in sea turtles and other migratory animals. Recent experiments indicate that the map sense of sea turtles is based at least partly on information derived from the Earth’s magnetic field.
Albert, a hawksbill was the first turtle to be tracked in 2005 and the second male turtle from Bonaire ever to be tracked. After being fitted with a transmitter on June 8th, Albert hung around Bonaire for another 150 days before heading to Serranilla Bank, 1,400 kilometers from Bonaire. Male sea turtles almost never return to land after entering the water as hatchlings and very little is known about their migration behavior. Male hawksbills are thought to breed every year, as opposed to females who return only every two to three years. Also, males may not travel as far as females, because of their need to return to the breeding area every year. Male sea turtles are known to depart from the breeding area earlier than females, which is why a male was selected for transmitter placement in June, while it was still early in the hawksbill nesting season.
Funny, a female hawksbill turtle was fitted with a satellite transmitter after nesting on November 22nd at No Name Beach, Klein Bonaire. She was the fifth turtle to be tracked in a busy tracking season for STCB. After staying around 15 days to lay a final nest, her fifth or sixth of the season, Funny departed Bonaire for a 1,446 kilometer journey to her foraging grounds of Seranilla Bank, Honduras. Hawksbills typically lay four to six nests on 14-day intervals.
Named after Bonaire’s park management organization STINAPA, the female sea turtle, was the first green turtle to be tracked from Bonaire. She laid her fifth and final nest at Playa Chikitu on the October 31st and departed Bonaire the very next day with her transmitter in place. STINAPA traveled 2,026 kilometers to Miskito Cays Nicaragua. These waters are not an ideal destination for STINAPA as green turtles like her are legally harvested every year in Nicaraguan waters. Because of their size, shell and mobility green sea turtles only have two predators – sharks and people.
Tom, a hawksbill turtle was the first male sea turtles to be tracked from Bonaire. He was fitted with a satellite transmitter on July 13th, in order to help determine how long males remain in Bonaire waters during the breeding season. Tom departed Bonaire 93 days later heading northeast towards the Saba Bank, but unfortunately his signal was lost in October. Amazingly, Tom was found by STCB back at his breeding grounds near Klein Bonaire the following year with his transmitter still attached. This follows the theory that males return to their breeding grounds every year.
The second turtle to be tracked in 2004 was a very large (~150 kilograms) female loggerhead named Extra. On July 9th Extra was brought on board STCB’s research boat from her known resting reef, just off her nesting beach on Klein Bonaire. The very next day Extra was off on a 1,754 kilometer journey to her foraging waters of Banco Gorda Honduras. This area has eventually proven to be of prime importance to Bonaire turtles.
The first turtle of the 2004 tracking season was also the first loggerhead to be tracked from Bonaire. Happy was fitted with a transmitter June 24th after laying her final nest of the season on Klein Bonaire. Happy departed Bonaire four days later, heading across the entire Caribbean north to south to reach the east coast of the Dominican Republic. From there she followed the coast east all the way to the eastern coast of Puerto Rico off Vieques Island.
The second turtle tracked from Bonaire was a female hawksbill named Schillie who was fitted with a transmitter on November 2nd 2003, very late in the hawksbill breeding season. Schillie crossed the Caribbean north to the central coast of the Dominican Republic. Schillie then traveled 200 kilometers back towards Bonaire, before once again having a change of heart and looping northwest to arrive at her foraging grounds off Mona Island, Puerto Rico in early January 2004. Amazingly, Schillie was spotted again in August of 2005 during in-water turtle surveys off Monito island, where she was greeted by a familiar friend and had her transmitter removed.
The first ever turtle tracked from Bonaire’s waters brought a great deal of excitement and curiosity. Would she leave Bonaire after nesting? Where would she go? How fast would she travel? STCB started tracking turtles in order to answer questions like these as well as help determine the migratory routes and foraging locations of Bonaire’s breeding turtles in order to alleviate some of the threats they may face.
Being the first turtle tracked, Nautila, a female hawksbill did not disappoint. Nautila was fitted with a transmitter on October 24th 2003 and swiftly departed Bonaire’s waters the very next day. She traveled a total of 1,712 kilometers in 45 days all the way to Navidad Bank, 100 kilometers north of the Dominican Republic. Through the 2010 tracking season and 19 more turtles, Bonaire has yet to have a tracked turtle travel this far north again!.