9.3 Wednesday, Jan. 4 Potential trade-off between recovery from infection and current reproductive opportunity: social effects on sickness behavior LOPES, P.C.*; ADELMAN, J.S.; CHAN, H.; DEMATHIEU, S.L.; BENTLEY, G.E.; Univ. of California, Berkeley and GABBA, Univ. of Porto; Virgina Tech; Univ. of California, Berkeley; Univ. of California, Berkeley; Univ. of California, Berkeley firstname.lastname@example.org
Sickness behavior refers to a collection of symptoms, including weakness, lethargy and decreased appetite, exhibited by an animal over the course of an infection. While sickness behavior may increase the chances for survival by reallocating metabolic resources to fight infection, it may also decrease chances for other adaptive opportunities, such as mating. Therefore, it may be of adaptive value for animals to modulate their sickness behavior according to their environment. We examined the extent to which birds exhibit sickness behavior based on their social context. In the first experiment, we tested whether male zebra finches (Taeniopygia guttata), when maintained either in groups or in isolation, would alter sickness behavior. We injected the birds with a non-pathogenic bacterial component (lipopolysaccharide, LPS). While birds kept in a group showed no overt behavioral signs of infection, isolated birds significantly reduced activity after an LPS injection. Critically, LPS birds in both social settings exhibited similar physiological immune responses. These data suggest masking of sickness behavior in the presence of conspecifics. In the second experiment, we tested specifically whether the presence of a novel female suppressed sickness behavior in male finches. Activity was decreased in isolated birds injected with LPS. When presented with a novel female, both LPS and control males became highly active and courted females to an equal degree. Our results suggest that male zebra finches prioritize the opportunity for current reproductive investment over allowing recovery from infection.