Sea Turtle Conservation Bonaire

Other tracked turtles 2007 (click on the name for more information): Eloise

November 17th, 2007

Unfortunately it looks like we are no longer receiving signals from ‘Darwina’. As you can see from today’s tracking map, the last signal was received over 2 days ago on the morning of 14 November. The most likely explanation is that the antenna on ‘Darwina’s transmitter has broken off and the device can no longer send signals.

‘Darwina’ was first fitted with her transmitter back on 24 July. She traveled extensively in-between her nesting activities on the southern part of Bonaire, with a couple of journeys to Venezuela and Curacao, and to Los Roques. Her migration back to her home foraging grounds, which began on 29 September, took her over 2200 km from Bonaire before her signal was lost. The actual path she covered exceeded 2750 km. All told, since having the transmitter affixed, ‘Darwina’ traveled just short of 7000 km!

For your information, we are still receiving signals from ‘Eloise’ that place her in her last reported position on the Albatross Bank off Jamaica.

We will continue to monitor the situation and if circumstances should change, we will keep you posted.

« click on this image to enlarge

November 13th, 2007

‘Darwina’ has left the waters of Belize and is now swimming along the coast of Mexico. Ahead of her lies Banco Chinchirro and still further north the island of Cozumel and Cancun. (It has been suggested by one of our subscribers that “Darwina’ is headed to Cancun for rest and a massage.) Currently, ‘Darwina’ is over 2200 km from Bonaire and is traveling at a rate of over 40 km per day.

November 11th, 2007

Our female Green turtle ‘Darwina’ is continuing to the north and is now right off the northern edge of the Turneffe Islands. She has reduced her speed and is moving at a rate of approximately 35 km per day. The Turneffe Islands Atoll is comprised of more than 200 small mangrove cayes and a cluster of coral islands surrounding a lagoon. The Turneffe Atoll is 30mi/49km long and 10mi/16km wide, and is one of three atoll reefs in Belize's waters.

November 9th, 2007

‘Darwina’, our most amazing female Green turtle, has passed the Bay Islands, turned to the north, and is swimming parallel to the coast of Belize. Her current position puts her just north of Glover Reef and headed toward Lighthouse Reef and the Turneffe Islands.

Glover Reef is one of the three off-shore atolls within the Belize barrier reef section of the Mesoamerican Barrier Reef. It is approximately 45 km off the coast of Belize and is located at the southern most end of the Belize Barrier reef. The reef is an oval-shaped atoll measuring 32km long and 12km wide.

‘Darwina’ is now over 2180 km from Bonaire! Our previous long distance champ was ‘STINAPA’, another female Green turtle. In 2004, we tracked ‘STINAPA’ to the Miskito Cays off the coast of Nicaragua over 1600 km away. Since placing the satellite transmitter on ‘Darwina’ on 25 July, her current travel plus her various jaunts to Venezuela, Curacao and around Bonaire have covered over 6700 km! She’s amazing!

November 7th, 2007

‘Darwina’, our female Green turtle, is now approximately 35 km north of Roatán and still headed to the south-west. She is traveling at a rate of over 55 km per day and is currently over 2040 km from Bonaire.

November 5th, 2007

‘Darwina’ is continuing to move to the south-west and is now headed in the general direction of the Bay Islands. She is currently traveling a pace of approximately 40 km per day and is 1940 km from Bonaire. Located about 65 km off the northern coast of Honduras, the Bay Islands group consists of three main Islands (Roatán, Guanaja, and Utila), three smaller islands (Barbareta, Morat, and Helene), and 65 smaller cays. Between these islands and the mainland are the Cayos Cocinos (Hog Islands).

November 2nd, 2007

Our Green turtle ‘Darwina’ has significantly increased her pace over the last several days. She is now traveling at a daily rate of about 100 km per day and is passing south of the Swann Islands, heading in a south-westerly direction toward Honduras. Her current location places her at approximately 1780 km from Bonaire. The Swan Islands, part of Honduras, are located about 90 miles off the coast of mainland Honduras. Three islands constitute the Swan Island chain: Great Swan, Little Swan, and Booby Cay. Many thanks to Anouschka van de Ven for all her hard work in doing the satellite tracking during my absence.

October 29th, 2007

‘Darwina’, our Green turtle, has left the Pedro Bank and is just off the west coast of Jamaica, headed in a north-westerly direction. She’s traveling at a rate of about 44 km per day. Will she venture on to the Cayman Islands to join the large population of Green turtles that live there? We’ll keep you posted!

October 23rd, 2007

‘Darwina’, our Green turtle has slowed down considerably to a speed of under 40 km per day as she is approaching her first shallow-water area after leaving Bonaire. She is nearing the Pedro Bank, which belongs to Jamaica and she is now just over 1170 km from her starting point.

October 18th, 2007

‘Darwina’, our Green turtle, is moving in a north-westerly direction. She’s approximately 1050 km from Bonaire, and traveling at a rate of around 53 km per day.

October 14th, 2007

Our Green turtle ‘Darwina’ is now traveling at a rate of just under 65 km per day. She’s headed in a westerly direction, and she’s now about 840 km from her starting point.

October 11th, 2007

Our Green turtle ‘Darwina’ has picked up her speed slightly and is now traveling at a rate of over 60 km per day. She is over 630 km from her starting point on Bonaire and still headed in a north-westerly direction. Will she be joining ‘Eloise’ on the Albatross Bank? We will keep you posted!

October 8th, 2007

Our Green turtle ‘Darwina’ is traveling at a rate of approximately 56 km per day and she’s still moving in a north-westerly direction. She is now about 424 km from Bonaire.

October 5th, 2007

‘Darwina’, our Green turtle, is traveling in a north-westerly direction. She is 280 km from Bonaire, and she’s moving at a rate of approximately 60 km per day.

October 3rd, 2007

Our female Green turtle ‘Darwina’ is now headed west and is just past Curacao. She is traveling at a rate of approximately 65 km per day and is over 110 km from her starting point on the southern end of Bonaire. Will she circle Curacao and return to Bonaire once again or will she continue on to the west? We will keep you posted.

October 1st, 2007

'Darwina' left on the morning of September 29th and swam around the southern most point of Bonaire. She's now headed in a north-westerly direction and is now over 70 km from her starting point.

September 27th, 2007

This morning, during a regular beach patrol, Funchi confirmed a new nest down at ‘Darwina’s favorite nesting site. Satellite signals have ‘Darwina’ last coming ashore late on the night of 25 September. This is ‘Darwina’s sixth nest. She last nested on or around 7 September, about 19 days ago. Typically Green turtles nest around every 14 days or so. ‘Darwina’ is anything but typical! 'Darwina' is currently hanging out of the shore of Bonaire.

September 24th, 2007

Very strong signals from our female Green turtle ‘Darwina’ have her coming ashore somewhat south of our prior nesting site at around 10 PM local time. A search of the beach failed to confirm the nest. Signals from last night have her possibly on shore once again.

September 21st, 2007

After swimming back and forth along the eastern portion of Curacao, ‘Darwina’ has once again returned to Bonaire. I imagine within the next day or so, she will be off her preferred nesting beach on the west coast of Bonaire. Per the data from the Satellite Tracking and Analysis Tool at SeaTurtle.org website, ‘Darwina’ has traveled over 3400 km since being fitted with her satellite transmitter some 58 days ago.

September 17th, 2007

‘Darwina’s signals have all over the place. After sorting through all the data, I think I have her position, if not her actual path, recorded accurately. She is currently just over 50 km from Bonaire.

September 15th, 2007

‘Darwina’ is back to Curacao and turning to the east towards Bonaire. Her rate of travel is about 63 km per day and she is now 80 km from Bonaire.

September 14th, 2007

Our female Green turtle ‘Darwina’, after spending a number of days along the coast of Venezuela, is headed north toward Curacao. She is currently 35 km north of Venezuela and approximately 100 km from her starting point on Bonaire. If she is going to return to nest again, she will probably be back in our vicinity no later than early next week.

September 12th, 2007

Signals from 'Darwina' have been very sporadic. She remains just off the coast of Venezuela in the same general area as previously reported.

September 11th, 2007

‘Darwina’ is still in the general area where she was reported to be yesterday, right off the coast of Venezuela.

September 10th, 2007

Our female Green turtle, 'Darwina’ has continued to the southwest and is now right off the coast of Venezuela. She is traveling at a rate of over 54 km per day and is approximately 105 km from her starting point.

September 8th, 2007

It looks like our female Green turtle, “Darwina’ started moving to the south early yesterday morning. She is currently over 40 km away from her starting point. ‘Darwina’ has made several journeys after nesting only to return to Bonaire and nest again. We will have to see if she is really headed home or will return to lay what would be her sixth nest of the season.

September 7th, 2007

We were unable to confirm that 'Darwina' had nested the other night. Based on the time since her last nest we think she must have nested and we simply can't find it. The normal period between nests for a Green turtle is 12 to 14 days. In any event, 'Darwina' is still in the area.

September 5th, 2007

A check of the beach yesterday failed to confirm 'Darwina's fifth nest. Signals place her back on the beach once again last night so another check for a nest will be done.

August 29th, 2007

'Darwina's last reported position puts her just south of Lac Bay on the east coast of Bonaire.

August 26th, 2007

'Darwina' appears to be moving slowly back towards Bonaire.

August 25th, 2007

‘Darwina’ is approximately 25 km west of Bonaire and is slowly meandering over very deep water. I suspect she will be returning to Bonaire to nest once again in the not too distant future.

August 23rd, 2007

‘Darwina’, our female Green turtle, is proving to be quite a challenge to track. In the last update it was noted that her signals possibly placed her on the beach during the morning of 20 August. After checking the beach later that morning, Funchi Egberghts reported that ‘Darwina’ had indeed come ashore and that she had crawled extensively along the shore. No evidence of a nest was found.

Subsequent signals have her swimming south past and around Willemstoren Lighthouse and then returning to her nesting beach, coming ashore again the night of 21 August at around 10 PM local time. She departed at approximately 1:30 AM on 22 August after laying her fourth nest of this season. Her nest was confirm by Funchi the next day. As is her habit, she is now moving slowly away from Bonaire, once again to the south.

August 20th, 2007

The signals we are receiving from ‘Darwina’s transmitter are very strong and many of them place her in extremely close proximity to the beach. It is even possible that she has already nested but we have not confirmed a new nest. Based on her track record to date, we believe that she will nest either tonight or the next night. We will keep you posted.

August 18th, 2007

After 10 days of travel, ‘Darwina’ is right out in front of the beach on which she last nested in the early morning hours of 8 August. By my count she will nest again several days from now.

August 16th, 2007

Our female Green turtle ‘Darwina’ is once again with us. After a brief tour of the waters around Curacao, she is now off the northeast coast of Bonaire.

August 14th, 2007

‘Darwina’ continues to move very slowly along the coast of Curacao. In the preceding 22 hours, she covered a little over 20 km, turning around the eastern tip of the island and heading to the north west over shallow waters. It is very possible that she is feeding after her long fast. Female sea turtles do not eat while they are nesting and if she is eating, it means that she will not returning to Bonaire again this nesting season. Further, it could also be possible that Curacao is her home foraging grounds. We will have to wait and see.

August 13th, 2007

‘Darwina’, our female Green turtle, is moving very slowly to the east along the southern coast of Curacao. Since her last plotted position back on 11 August, she has only swam some 35 km. She is slightly over 50 km from Bonaire. If ‘Darwina’ is going to return to Bonaire to nest again, she would be arriving here on or around 22 August. At the moment, she appears not in too much of a hurry to go anywhere in particular.

August 12th, 2007

The signals currently being received from ‘Darwina’ do not give a strong indication of her actual location but do show that she is still in the same general area off the coast of Curacao as she was yesterday.

August 11th, 2007

Our female Green turtle ‘Darwina’ is moving to the northwest and is currently over 80 km west of Bonaire, right off the coast of Curacao. Since her last reported position, she has swam approximately 100 km and is moving at a leisurely pace of about 2 km per hour.

August 9th, 2007

And she’s off, again! It is not possible to tell exactly when she started moving away from Bonaire but it appears that her latest jaunt began sometime after 8:00 AM yesterday. Her last position places her slightly over 40 km to the southwest. Where is she off to this time? Will she come back and nest again? We will keep you posted.

August 8th, 2007

She’s back! ‘Darwina’ came ashore shortly before 2:00 AM Bonaire time, right in the area in which she last nested back on July 25. She spend approximately 2 hours on shore, leaving around 4:00 AM. Subsequent signals we received are confusing and her path after leaving the beach is unclear. This is the third nest for ‘Darwina’ this season. STCB staff were on the job bright and early this morning and have already confirmed the nest.

Concerns regarding ‘Darwina’ having lost her way were apparently unfounded.

August 6th, 2007

Issuance of this update was delayed as we waited to confirm that ‘Dawina’ had really moved out of Las Aves and traveled back to the west, past Bonaire. The latest data now has her changing direction once again and moving to the northeast right toward Bonaire.

Since her last posted position on 04 August, ‘Darwina’ has traveled approximately 218 km and is swimming at a rapid rate of about 6 km per hour. She is currently 55 km from Bonaire.

This is not the first time one of our tracked turtles has “lost” her way during a migration home. Back in 2003, the very first turtle we tracked, ‘Nautilla’ made a large loop as she made her way from Bonaire to the Navidad Banks north of the Dominican Republic.

How sea turtles navigate to specific geographic targets is still a mystery. 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. Until recently, however, little was known 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.

August 4th, 2007

‘Darwina’, our female Green turtle is swimming in and around the Las Aves Archipelago. Yesterday, she swam about 35 km and she is approximately 55 km east of Bonaire. Our second image is once again from Google Earth and it shows ‘Darwina’s path across the archipelago. The notation “60728” on the left-hand side of the image is ‘Darwina’s Argos designation. The accompanying red circle is her last recorded position. Argos is the satellite-based location and data collection system dedicated to monitoring and protecting the environment and the source of our tracking data. Argos has been operating since 1978 and was initiated under an agreement by NOAA (the National Oceanic and Atmospheric Administration, USA), NASA (National Aeronautics and Space Administration, USA) and CNES (the French Space Agency.

‘Darwina’s path across Las Aves Archipelago

August 3rd, 2007

Since our last update, ‘Darwina’ has traveled slightly over 100 km and has entered the Las Aves Archipelago. She swam at a rate of over 60 km per day and is over 85 km from Bonaire. The second image below, taken from Google Earth, is of Las Aves. The red “X” marks ‘Darwina’s approximate position within the archipelago. The archipelago consists of two atoll-like reef complexes:
• Aves de Barlovento, the eastern group, with a fringing reef of 8 km of diameter and with three cays in the southwest.
• Aves de Sotavento, the western group, with a large mangrove-covered cay in the south.
In total, there are 13 islets in both groups.

Google Earth view of Las Aves. The red “X” marks ‘Darwina’s approximate position

August 2nd, 2007

After making a sharp turn, our female Green turtle ‘Darwina’ is now headed to the north. In front of her are Las Aves and Los Roques Archipelagoes, each over 80 km away. These archipelagoes both belong to Venezuela. Last year, we tracked “Heit’, a female Hawksbill, to Los Roques after she nested on Bonaire. ‘Darwina’ is approximately 135 km southeast of Bonaire and traveling at a rate in excess of 50 km per day.

August 1st, 2007

‘Darwina’ is continuing in an easterly direction, paralleling the coast of Venezuela. She is currently over 150 km south of Bonaire and traveling at a rate of approximately 30 km per day, slower than her last reported pace. Her position is approximately 40 km off the coast of Venezuela.

July 30th, 2007

Our female Green turtle ‘Darwina’ has turned to the southeast and is approximately 115 km from Bonaire. She is traveling at a rate of approximately 48 km per day and is about 60 km north of the Venezuelan coast.

July 29th, 2007 -'Darwina' departs from Bonaire

‘Darwina’, our female Green turtle, departed from the southern coast of Bonaire during the morning of 25 July, probably right after being fitted with her satellite transmitter. Her path has taken her due south toward Venezuela and it appears that she is turning to the east. If you will remember, ‘Darwina’ came ashore on the evening of 24 July to lay, what was believe to be, her second nest of this season and it was thought that she would stay in the area a while longer to lay additional nests. ‘Darwina’ is over 80 km from the southern tip of Bonaire and swimming at a rather leisurely pace.

July 25th, 2007 - Green turtle 'Darwina' is the second turtle tracked from Bonaire this nesting season

A Green turtle (Turtuga Blanku), nesting on the Atlantis dive site on the southern coast of Bonaire, was fitted with a satellite transmitter Tuesday night by a team of staff and volunteers from Sea Turtle Conservation Bonaire (STCB). This is the second turtle to be tracked during the current nesting season and the second Green turtle ever fitted with a transmitter on Bonaire.
Based on the pattern of turtle nesting activity observed during the last few weeks, it was predicted that the Green turtle would possibly return to the beach on Tuesday night. During a beach patrol on Tuesday morning, STCB's Funchi Egbreghts found crawl tracks from a turtle but observed that it was a false nesting attempt. So the team set out that night to monitor the area around the dive site.

Around 8:30 pm, a large Green turtle came ashore, but it took her three hours before she found a spot to lay her nest. When attempting to deploy a transmitter, it is important that the turtle be allowed to nest before starting the deployment process. If she decides to go back to the sea, we let her go and wait for her to come back and safely lay her nest. This is done in order to protect her clutch and avoid extra stress on the animal. At 11:30 pm, she began laying eggs. She was then measured (95.5 cm (37.6 in) straight carapace length) and tagged on her front flippers. An hour later and after she had thoroughly covered the nesting area with sand, the approximately 140 kg (309 lb) turtle was fitted with a satellite transmitter. At 2:30 am, the Green turtle was released and she quickly departed into the sea.

This was 'Darwina's' second nest of this season and it is anticipated that 'Darwina' may lay one or more nests before she leaves the area to return to her home foraging grounds.

Green turtle 'Darwina' will be the second turtle to be tracked from Bonaire during the 2007 nesting season. Tracking of this Green turtle is made possible by a full sponsorship provided by Karen and Ken Miller.

Earlier this month, the female Hawksbill 'Eloise' was fitted with a transmitter after nesting at No Name Beach on Klein Bonaire. 'Eloise' is still in the area and may be departing shortly.

The turtle tracking works through signals sent out by the transmitter, which is switched on whenever the turtle comes to the surface to breathe. These transmissions are then collected by Argos system receivers onboard weather satellites that circle the globe, yielding location data for each turtle that are e-mailed daily to Sea Turtle Conservation Bonaire.

Sea Turtle Conservation Bonaire exists to ensure the protection and recovery of Bonaire's sea turtle populations throughout their range. Founded in 1992, the STCB is a Bonaire-based, non-governmental and non-profit organization, part of the Wider Caribbean Sea Turtle Conservation Network.

On the picture: STCB's Mabel Nava and Funchi Egbreghts with 'Darwina'.