Inter-Research > ESR > v10 > p39-45  
ESR
Endangered Species Research

via Mailchimp

ESR 10:39-45 (2009)  -  DOI: https://doi.org/10.3354/esr00215

Monitoring beak movements with an acceleration datalogger: a useful technique for assessing the feeding and breathing behaviors of sea turtles

Junichi Okuyama1,*, Yuuki Kawabata1, Yasuhiko Naito2,3, Nobuaki Arai1, Masato Kobayashi4

1Graduate School of Informatics, Kyoto University, Yoshida Honmachi, Sakyo, Kyoto 606-8501, Japan
2National Institute of Polar Research, Itabashi, Tokyo 173-8515, Japan
3Bio-logging Institute, 2-3-10 Rex Yushima 301, Bunkyo, Tokyo 113-0034, Japan
4Yaeyama Station of the Stock Enhancement Technology Development Center, Seikai National Fisheries Research Institute, Fisheries Research Agency, Fukaiohta 148, Ishigaki, Okinawa 907-0451, Japan

ABSTRACT: This study was performed to determine whether the attachment of acceleration dataloggers to the lower beaks of loggerhead turtles Caretta caretta could be a useful technique for monitoring their feeding and breathing behaviors. Attaching acceleration dataloggers to the lower beak of turtles allows determination of the pitch of the head from the low frequency component of the acceleration data, and of dynamic movements (e.g. biting) from the high frequency component. In addition, to determine whether the acceleration datalogger could distinguish between different food sources and feeding locations based on acceleration characteristics, we fed the turtles with different types of food (squid rings, fins, and heads that include arms and tentacles) across different locations. Our results demonstrate that the acceleration datalogger was able to detect the lower beak movements of loggerhead turtles, which enabled detection of 99.6 ± 1.1 (SD) % of feeding and 100% of breathing behaviors, with respective false detection rates of 24.8 ± 12.4% and 2.4%. Furthermore, our results demonstrate that it is possible to (1) determine whether feeding on prey requires a strong biting force, and (2) differentiate between feeding at the sea floor and in the water column. Attaching an acceleration datalogger is thus established as a useful technique for monitoring the feeding and breathing behaviors of sea turtles. Future studies employing acceleration dataloggers should provide new insights into the biology of sea turtles and their feeding and diving strategies.


KEY WORDS: Biologging · Caretta caretta · Feeding ecology · Respiratory physiology


Full text in pdf format 
Cite this article as: Okuyama J, Kawabata Y, Naito Y, Arai N, Kobayashi M (2009) Monitoring beak movements with an acceleration datalogger: a useful technique for assessing the feeding and breathing behaviors of sea turtles. Endang Species Res 10:39-45. https://doi.org/10.3354/esr00215

Export citation
Mail this link - Contents Mailing Lists - RSS
Facebook - - linkedIn