Baseline (a) and stress-induced (b) corticosterone (CORT) titers of house sparrows before initiation of a feeding study (Week 0), and then two weeks and four weeks after exposure to a 1% oil or a control diet (Week 2 and Week 4) (n = 12 birds in each group).

<p>The hash represents a significant decrease in stress-induced CORT titers in the birds on the 1% oil diet at four weeks compared to their own values at the initiation of the feeding study; the star represents a significant decrease in stress-induced CORT titers in the birds on the 1% oil diet compared to the controls at 4 weeks. Values are presented as mean ± SEM.