Table 1.

Animal response to playback stimuli

Treatment	Group size	Whistle rate before (no./min/individual)	Whistle rate after (no./min/individual)	Movement response (m)	High similarity whistles (reply)
(U) Control 1Sy.	8	0.187	0.5	−40	0
(U) Control 2Sy.	5	0.8	0.6	−55	0
(U) Control 3Sy.	10	0.3	0.3	+30	0
(U) Control 4Sy.	24	0.0	0.0	—*	0
(U) Control 5Sy.	13†	0.16	0.07	−30	0
(U) Control 6Sy.	11	0.18	1.72	0	0
(U) Control 7Sy.	25	0.32	0.04	−30	0
(U) Control 8Sy.	25	0.28	0.0	0	0
(U) Control 9Sy.	8	0.625	0.5	+140	0
(U) Control 10Sy.	3	0.0	2.33	−180	0
(F) Control 1N.	13†	0.0	0.0	−20	0
(F) Control 2N.	13†	0.0	0.0	0	0
(F) Control 3N.	13†	0.0	0.0	0	0
(F) Control 4N.	10	0.7	0.2	+20	0
(F) Control 5N.	10	0.0	0.6	+5	1
(F) Control 6N.	2	0.5	0.0	0	0
(F) Control 7N.	2	0.0	0.0	0	0
(F) Control 8N.	6	0.0	0.83	−80	3
(F) Control 9Sy.	22	0.54	0.14	−70	0
(F) Control 10Sy.	25	0.0	0.12	0	0
(F) Control 11Sy.	3	0.67	1.3	+10	0
(F) Control 12Sy.	30	0.03	0.26	−20	0
Treatment 1Sy.	10	1.1	1.1	−70	2
Treatment 2Sy.	3	1.67	3.3	+150	4
Treatment 3Sy.	9	0.0	0.4	+30	1
Treatment 4Sy.	4	0.0	1.0	+20	1
Treatment 5Sy.	17	0.0	0.23	−30	1
Treatment 6Sy.	21	0.9	0.0	+35	0
Treatment 7Sy.	22	1.22	0.59	+30	0
Treatment 8Sy.	5	0.4	0.0	−10	0
Treatment 9Sy.	23	0.26	0.13	0	0
Treatment 10Sy.	11	11	0.45	−70	1
Treatment 11N.	15	1.06	0.4	−20	7
Treatment 12N.	12†	0.0	0.58	—*	5

For each playback type the group size is shown along with whistle rates (number of whistles divided by group size) before and after playback, the movement response and whether animals replied to the playback. Superscript “Sy.” denotes synthetic stimuli and “N.” denotes natural stimuli. F, familiar control; Treatment, copy playbacks; U, unfamiliar control).

^*Equipment failure meant movement response was not available for these playbacks.

^†Group sizes were estimated as photo-identification was not available for these playbacks.