Figure 2. Top row: Singing increased as night progressed (black = overall means + SE; colored lines= individual means per hour). Mean +/- SE amount of singing per night per individual correlated with number of singing perches. Higher percentage of time spent singing at preferred perches was negatively correlated with core range size. Bottom row: E = Early range, L = late range, N = total night range, S = singing range. 95% and 50% night ranges, and 95% early ranges, were significantly larger than singing ranges.