This blog was created to allow the public to follow two manatees, Rita and her calf Georgie, as scientists track them after their release back into the wild. Please return for weekly updates.
NOTES FROM THE FIELD – WEEK 5:
Scattered thunderstorms prevented Willie, Beth and Kendria from going out early to check on Rita and Georgie but finally by 4pm, the rain had held up just enough to search for the tagged manatees. After traveling for over 70 miles around Great Harbour Cay to the south and back, they had safely returned to Bullock’s Harbour. We found them with the adult and juvenile male and observed them feeding on seagrass beds. Georgie remained very close to her mother, Rita, as they were feeding and socializing with the other manatees.
We are able to track the manatees using two methods: signals received using a VHF radio receiver and through locations derived from satellites passing overhead. These can be downloaded from Argos’ website throughout the day and, unlike the radio receiver isn’t dependent on us being within receiver range of the animals which isn’t always possible because of bad weather conditions. If the animals are not within radio range, using a combination of both methods can be best; first check the Argos location, then travel to the general area and use the VHF receiver to actually find them.
Argos categorizes satellite locations received from their tags by ‘quality code.’ These codes are essentially a measure of location (latitude and longitude) accuracy. Accuracy is affected by how much of the tag’s transmitter is above the water’s surface as a satellite passes overhead and also how many satellites passing overhead picked up the same transmission. Accuracy can range from 100 meters to tens of kilometers so close attention must be paid to the quality code (Deutsch et al. 2003).
Deutsch, C. J., Reid, J. P., Bonde, R. K., Easton, D. E., Kochman, H. I., & and O'Shea, T. J. (2003). Seasonal Movements, Migratory Behavior, and Site Fidelity of West Indian Manatees Along the Atlantic Coast of the United States. The Journal of Wildlife Management: Wildlife Monographs 151 , 1-77.