Table 2.

Estimates of the effect of social transmission in each species.

species	social transmission rate per unit network connection(s)	per cent of events by social transmission (excluding innovation)
smooth-coated otters	45.2 (0.44–∞)a	96.0% (27.5–100%)
Asian short-clawed otters	dTADA: 0 (0–0.17)b	dTADA: 0% (0–17.3%)

^aNote that it is common for OADA to fail to put an upper limit on the strength of social transmission when the order of learning follows the network closely. This simply means it is plausible that all individuals learned by social transmission, except the innovator.

^bOADA was unable to precisely estimate the effect of social transmission in Asian short-clawed otters, so we also ran a dTADA for this species (see main text and electronic supplementary material, table S4).