Table 1. The fraction of all test fish that followed replica leaders towards the food patch.

		Initial group size
		1	2	4	8
Leaders	0	9/20	22/40	42/80	75/160
	1 0v.1	20/20 P<0.01	30/40 P = 0.061	52/80 P = 0.1	105/160 P<0.01
	2 0v.2 1v.2	19/20 P<0.01 P = 0.31	34/40 P<0.01 P = 0.26	58/80 P<0.01 P = 0.31	123/160 P<0.01 P = 0.03

The numerator is the number of test fish going to the food patch across all trials, the denominator is the number of test fish that started the trial. Tests to compare the number of fish that went to the food patch in the presence of 0 versus 1 leader, 0 versus 2 leaders and 1 versus 2 leaders between were carried out using a χ² test of independence. Two-tailed P values are presented for comparisons at each group size.