Figure 2.

Average proportion (±SE) of an individual bird’s beak that was red on days 50 and 65 posthatch grouped by young treatment. Birds were challenged with KLH (n = 36), LPS (n = 43), or PBS (control; n = 47) on days 5 and 28 posthatch. KLH-treated birds had beaks with less red coloration on day 50 than the other 2 groups, but all 3 treatments were similar on day 65, at which point an average of approximately 85% of a bird’s beak was red. Data here include both male and female zebra finches.