Christopher Bertola, Jaimie Abraham, Joseph Celeste, Danial Rehman, Abbas Merchant, Vivienne Nguyen and Maria Paez

Abstract:

Nearly all birds possess a uropygial (preen) gland which produces a mix of waxes and oils. Preen secretions are anointed onto feathers while birds are preening and help maintain feather condition. However, researchers have also proposed that components of preen oil may also act as a chemical defense against feather-degrading parasites. Here, we test the behavioral responses of feather-feeding lice to preen oil. We show that lice reduce their turning rate when directly exposed to preen oil and exit feathers more often when they contain preen oil. Lice that exited oiled feathers also showed a dramatic reduction in survival. However, lice forced to remain near preen oil showed no reduction in survival. We further show that birds infested with lice produce more preen oil than louse-free birds, however the chemical components of the preen oil appear similar. While preen oil clearly impacts louse behavior, further experiments are needed to clarify the direct and indirect impacts of preen oil on louse behavior and survival.