Differences in diurnal and nocturnal swimming patterns of olive ridley hatchlings in the Gulf of Fonseca, Honduras

作者：Duran N^*; Dunbar S G

来源：Journal of Experimental Marine Biology and Ecology, 2015, 472: 63-71.

DOI：10.1016/j.jembe.2015.07.003

• Lepidochelys olivacea
• Sea turtle
• Predation
• Anti-predatory behavior
• Off-shore migration
• Swimming patterns

Sea turtle hatchlings from Honduran beaches along the Pacific coast must swim more than 30 km through the shallow, presumably predator-rich waters of the Gulf of Fonseca before reaching the open ocean. Olive ridley hatchlings from Punta Raton, Honduras, were tracked during the first 2 h of their offshore migration to assess aquatic predation rates. No predation events were observed. The absence of rocky bottom areas and reef structures where predators can refuge, and a decline in the number of predators due to overfishing are two possible reasons for this unexpected result. Additionally, diurnal and nocturnal swimming patterns of recently emerged olive ridley hatchlings were compared with regard to their position in the water column while swimming. At night hatchlings swam near the surface 97.5% of the time, with only sporadic brief dives. During daytime, however, hatchlings spent 78% of the time swimming at depth, going back to the surface for brief periods to breathe. Due to the high turbidity of the Gulf of Fonseca waters, this daytime behavior may serve to keep hatchlings out of sight of predatory sea birds. This newly described differential swimming behavior may have adaptive significance in avoiding aerial predation in the specific conditions of the Gulf of Fonseca.

• 出版日期2015-11