Video data from pop-off camera deployments on green sea turtles in San Diego, California
Data files
May 03, 2024 version files 105.68 GB
Abstract
The cryptic and aquatic life histories of sea turtles have made them a challenging group to directly observe, leaving significant knowledge gaps regarding social behavior and fine-scale elements of habitat use. Using a custom-designed animal-borne camera, we observed previously undocumented behaviors by green turtles (Chelonia mydas) at a foraging area in San Diego Bay, a highly urbanized ecosystem in California, USA. We deployed a suction-cup-attached pop-off camera (manufactured by Customized Animal Tracking Solutions) on 11 turtles (mean straight carapace length = 84.0 ± 11.2 cm) for between 1 and 30.8 h. Video recordings, limited to sunlit hours, provided 73 h of total observation time between May 2022 and June 2023. We observed 32 conspecific interactions; we classified 18 as active, entailing clear social behaviors, as compared with 14 passive interactions representing brief, chance encounters. There was no evidence for agonistic interactions. The camera additionally revealed that green turtles consistently use metal structures within urban San Diego Bay. In seven instances, turtles exhibited rubbing behavior against metal structures, and we observed two examples of turtles congregating at these structures. High rates of intraspecific interaction exhibited relatively consistently among individuals provide a compelling case for sociality for green turtles in San Diego Bay, adding to a growing research base updating their historical label of “non-social.” The frequent use of metal structures by the population, in particular the rubbing of exposed skin, has implications for behavioral adaptations to urban environments. Our study exemplifies the promise of technological advances (e.g., underwater and animal-borne cameras) for updating natural history paradigms, even for well-studied populations.
README: Video data from pop-off camera deployments on green sea turtles in San Diego, California
https://doi.org/10.5061/dryad.05qfttf9t
Video data were collected via a deployable, underwater pop-off camera that was attached to foraging green sea turtles (Chelonia mydas) in a series of deployments within San Diego Bay, California, USA over 2022–2023.
San Diego Bay represents a regionally important foraging area for East Pacific green turtles and hosts a mix of size/age classes. More information on turtles sampled and deployment metadata can be found in the accompanying open access journal article by Mullaney et al. (2024); http://doi.org/10.1002/ece3.11282.
The pop-off camera was manufactured by Customized Animal Tracking Solutions (CATS) and attached with suction cups to the carapace of individual turtles after capture with entanglement nets during annual mark-recapture monitoring by scientists with NOAA's Southwest Fisheries Science Center and collaborating partners. Research activities were permitted under NOAA Research Permit No. 18238-03 and NOAA Institutional Animal Care and Use Committee Permit No. SWPI 2020-03.
The CATS device was programmed to record when there was sufficient light to ascertain turtle behaviors within the video frame. Deployment length was controlled through the use of different galvanic timed-release mechanisms, and was also affected by attachment quality (i.e., some failure did occur) and turtle behavior (i.e., turtles occasionally dislodged suction cups). After the camera popped off and was recovered, video data were downloaded and a single observer reviewed video to characterize turtle behavior.
Description of the data and file structure
Video data are provided in .mp4 format at 720p resolution with no audio. All usable videos collected from a camera deployment have been zipped into a designated folder. These folders (n=10) are accordingly labeled as deployment 1 through 11, skipping deployment 8, which was a failed deployment.
Table 1 in Mullaney et al. (2024) summarizes deployment timing, length, and other metadata. Local time and date are provided in the bottom right of the video pane.
Sharing/Access information
Video data are made publicly available here. Contact the authors for more information.
Data are summarized in Mullaney et al. (2024), available open access at the following link: http://doi.org/10.1002/ece3.11282
Methods
Data were collected via deployable camera manufactured by Customized Animal Tracking Solution and custom-designed for sea turtles. See Mullaney et al. (2024) for elaboration, available open access at the following link: http://dx.doi.org/10.1002/ece3.11282