Using an in-situ infra-red camera system for sea turtle hatchling emergence monitoring

Abstract

We tested for the first time the efficiency of the use of infra-red (IR) cameras for sea turtle hatchling monitoring. The cameras were installed on one green turtle ( Chelonia mydas ) and four loggerhead turtle ( Caretta caretta ) nests during 2014 and 2015 nesting season in the south-east Mediterranean, Turkey. The camera monitoring, even with the limited sample size, have successfully corroborated the previous observations and provided further insights on hatchling emergence behavior. The analysis of the camera recordings revealed that hatchlings emerged from the nests asynchronously in varying numbers of groups and different group sizes, while c. 60% hatchlings emerged during the first 5 days of emergence activity. 98.6% of hatchlings emerged at night with a peak activity between 21:00 and 00:00. The day of first emergence varied between 38 and 64 days since egg deposition, while the day of last emergence varied only between 60 and 65 days. Total emergence activity continued up to maximum of 22 days, which is longer than that of previous records. Overall, the present study showed that IR camera monitoring is a promising tool for sea turtle monitoring and can provide detailed insights on sea turtle hatchling behavior.