A study by Jaleta et al. in the Malaria Journal suggests that chickens may be helpful in the fight against malaria. Results show that Anopheles arabiensis is a selective blood feeder when host-seeking indoors, which prefers human blood and avoids cattle blood. In contrast, when found outdoors, An. arabiensis is an opportunistic blood feeder, randomly feeding on cattle, goats and sheep and avoiding humans. While An. arabiensis feeds on many abundant vertebrate species, this study shows that it avoids chickens despite their relatively high abundance. Mosquitoes select their meal using their sense of smell, so that the “detected volatile profiles associated with the various hosts provide a chemical signature” to indicate excellent dining — evidently, the chicken does not qualify. In their testing, they found that eight bioactive compounds reduced mosquitoes caught in traps – as did suspending a caged chicken next to the traps. Researchers conclude that volatile compounds identified in the headspace extracts of chicken feathers appear to play a pivotal role in the observed non-host avoidance. Compounds that were able to disrupt the host-seeking behaviour of An. arabiensis included both chicken-specific and generic volatiles. This suggests that these volatiles function as medium- to long-range repellents. http://acsh.org/news/2016/08/06/chickens-malaria-zika-the-perfect-storm/
Lots of mosquitos like birds, prefer birds, and chickens descend from large, ground foraging, easily targeted birds. The evolutionary pressure to repel them would be significant, and of long standing. So if I were looking for mosquito repellents without toxicity to large, endothermic, vertebrate targets, I would look at ground foraging birds in mosquito rich environments - especially around the face.
