Aggressive interactions differentially modulate local and systemic levels of corticosterone and DHEA in a wild songbird

► We compare effects of aggressive interactions (STI) on local and systemic steroid levels. ► STI increased jugular, but not brachial, DHEA levels in both the breeding and nonbreeding season. ► STI increased corticosterone and DHEA in the liver during the nonbreeding season. ► Local steroid synthesis could avoid costs of systemic increases in corticosterone and testosterone.