Table 1.

All occurrences of recorded seashell interaction (tool use, no tool use or unknown). Individual and group frequency for each of the behaviours, as well as mean bout duration (MD) of the observed behaviour at an individual and group level are shown. Italicized subjects are those with no confirmed instances of tool use (only ‘seashell–unknown’ or ‘seashell–no tool’).

date pit–seashellpebble–seashellseashell–unknownseashell–no tool
subjectsexfreq.MD (s)freq.MD (s)Freq.MD (s)freq.MD (s)
TIM32535343177
JDM1755161391656613
WDM2181523
CIM134372595550
PLF1040410061116
CLF420
UFM214
GOF438
BWF143
THM54818
total (n)33400283455846816134
group mean6.6080.007.0086.257.2558.502.6722.33
group s.d.6.8097.616.0644.575.1854.622.2519.20