Figure 3.

Food intake of wild-caught (white dots) and hand-raised (black dots) birds; illustrated are means and standard errors. Numbers in the upper part of the panel identify individual experiments. Values on the x-axis identify the difference in sugar contents between both foods (in % of overall weight). Positive values indicate that red foods contained more sugar than orange foods, whereas negative values indicate higher sugar contents in orange foods. The line indicates food intake if birds consumed both foods equally.