Diving behaviour of whale sharks in relation to a predictable food pulse.
We present diving data for four whale sharks in relation to a predictable food pulse (reef fish spawn) and an analysis of the longest continuous fine-resolution diving record for a planktivorous shark. Fine-resolution pressure data from a recovered pop-up archival satellite tag deployed for 206 days on a whale shark were analysed using the fast Fourier Transform method for frequency domain analysis of time-series. The results demonstrated that a free-ranging whale shark displays ultradian, diel and circa-lunar rhythmicity of diving behaviour. Whale sharks dive to over 979.5 m and can tolerate a temperature range of 26.4 degrees C. The whale sharks made primarily diurnal deep dives and remained in relatively shallow waters at night. Whale shark diving patterns are influenced by a seasonally predictable food source, with shallower dives made during fish spawning periods.
Graham
Rachel T
RT
Wildlife Conservation Society, PO Box 37, Punta Gorda, Belize. rgraham@wcs.org
Roberts
Callum M
CM
Smart
James C R
JC
D000818:Animals; D001683:Biological Clocks / Q000502:physiology*; D004242:Diving / Q000502:physiology*; D005247:Feeding Behavior / Q000502:physiology*; D010507:Periodicity; D012754:Sharks / Q000502:physiology*; D013550:Swimming