Here is the first series of readings from the two leatherback turtles we tagged while they were nesting on the beach in Costa Rica. Will be sending updates as they arrive.
TURTLE DATE LATITUDE LONGITUDE 1111 Jan. 18 10.350 85.867(release site) 1111 Jan. 23 10.449 86.590 1111 Jan. 25 10.421 86.361 1111 Jan. 26 10.192 86.054 1111 Feb. 01 10.330 85.495
1112 Jan. 19 10.317 85.818(release site) 1112 Jan. 23 10.116 87.430 1112 Jan. 27 10.116 85.370 1112 Jan. 28 9.362 84.251 1112 Jan. 30 9.161 84.230
Keep in mind that these locations are only approximate because we only get very brief signals when the transmitters are bobbing in the waves when the turtle surfaces to breathe.
From previous experiences we know that some of the poorer quality readings may be off by 30 nautical miles. For long term global migrational studies this level of accuracy is adequate, but it may seem strange when the animals are near the coast and we get locational data placing the animals on land.
Here are questions for you to think about:
1) If these two turtles nested on the same beach, what do the latitude and longitude readings tell you about the accuracy of the telemetry? Give your answer in kilometers.
2) If the turtles were nesting when the transmitters were attached, and we know the nesting interval, on what days might we expect the turtles to again leave the water?
Ed ************************************************************* Mapping Sea Turtle Migration:
You can order a map for tracking this migration as described below. Perhaps a better idea is this activity suggested by teacher Marv Mikesh of Rochester, Minnesota:
"For teachers who are having difficulty finding appropriate maps, I would like to suggest the following activity.
Let the students create their own maps. All schools have a variety of maps contained within textbooks, reference materials and teacher support materials. Have the students find a map which they think is appropriate for the tracking of their particular species. Make a transparency of the map and, using an overhead, project the map on the wall at a desired size. Students can use fine point felt tip markers and create their own map. White butcher paper serves as a cheap source of paper for map construction.
Making Your Map
Where will the turltes go? What area should your map cover? Past turtles tracked by Dr. Standora from the Costa Rican beaches have traveled within this range:
Latitude 13 degrees North to 10 degrees South Longitude 84 degrees West to 98 degrees West
The best printed map for tracking this migration is Coastal Chart #21036, Region 2, from NOAA's National Ocean Service, U S. Dept. of Commerce. Latitudes Map Store in Minneapolis can mail this to you for $13.65. Phone: (612)927-9061, Fax: (612)927-9163. Explain that you are ordering for use with the Journey North program.
Remember: We can't guarantee this year's turltes will go where we expect them to!
Copyright Journey North, 1995. All Rights Reserved. jnorth@jriver.com