Figure 1.

Comparisons of (a) the mean number of days (±s.e.m.) between a pairs’ arrival in the colony and clutch initiation; (b) the mean number of days (±s.e.m.) from the mean laying date of the colony to the date that each pair initiated their clutch; and (c) the mean clutch size (±s.e.m.) for the three treatments (i.e. intra-colony:samples of sound were generated from their own colony; extra-colony:samples of sound were generated from a different colony; control:no sound supplements). Bars not sharing any letter are significantly different (p < 0.05, Tukey’s multiple-range tests).