Raouf and colleagues (2006) found that cliff swallow colony size is correlated with higher levels of glucocorticoid hormones. They further demonstrated that the stress was being produced by
A) a outbreak of nest robbing that would begin when some colony sizes exceeded normal levels.
B) high numbers of parasitic swallow bugs.
C) intense feeding competition within some of the colonies.
D) unusually aggressive forms of mate competition among the males of some colonies.

Question

Quizplus · Accepted Answer

Raouf and colleagues (2006) found that higher levels of glucocorticoid hormones in cliff swallows were correlated with high numbers of parasitic swallow bugs, indicating that the stress was due to parasitism.

Raouf and Colleagues (2006) Found That Cliff Swallow Colony Size