Hummingbirds are found to be able to sniff out insects, overturning the myth that birds have a weak sense of smell



Hummingbirds have the smallest body of any bird and are characterized by their wings flapping at high speed and hovering. A research team

at the University of California, Riverside has revealed that such hummingbirds have the ability to sniff out insects.

What is that smell? Hummingbirds avoid foraging on resources with defensive insect compounds
(PDF file) https://link.springer.com/content/pdf/10.1007/s00265-021-03067-4.pdf

Hummingbirds can smell their way out of danger | News
https://news.ucr.edu/articles/2021/09/06/hummingbirds-can-smell-their-way-out-danger

According to the research team, it has been shown that hummingbirds may have a sense of smell, but 'flowers that carry pollen to insects give off a strong odor, but flowers that carry pollen to birds smell less. It has been said that it is unlikely that the hummingbird's sense of smell has developed because it does not release. In this study, we set up a feeding box with the scents of multiple species of insects to investigate the possibility that hummingbirds are scenting insects rather than flowers, and confirmed the reaction of hummingbirds.



The figure below shows a case where a food box (gray) containing unscented sugar water and a food box (black) containing sugar water with the smell of hummingbirds are installed in a place where wild hummingbirds live. It shows the number of times the hummingbirds visited each food box in (A) and (B) when installed in the hummingbird breeding facility. If you look at the figure, you can see that hummingbirds, whether wild or bred, visit the feeding box without worrying about the smell of bees.



Next, the research team investigated the response of hummingbirds to formic acid secreted by ant venom glands and to the Argentine ant's guide pheromone, Z9-hexadecenal. The figures below show 'C: Which wild bees visit more often in sugar water (gray) or sugar water containing formic acid (black)' and 'D: Raised bees contain sugar water (gray) and formic acid', respectively. Which do you visit more often in sugar water (black)? '' E: Which do wild bees visit more often in sugar water (gray) or sugar water containing Z9-hexadecenal (black)? ' Which do you visit more often, water (gray) or sugar water containing Z9-hexadecenal (black)? ' If you look at the figure, you can see that hummingbirds avoid ant-derived odors in all cases C to F.



In addition to the above experiments, the research team said that ethyl butyrate gives off a non-natural odor to eliminate the possibility that 'hummingbirds avoided ant odors for the first time, rather than scenting them.' Conducted a similar experiment using. The results showed that hummingbirds do not avoid ethyl butyrate. The results show that the hummingbird's sense of smell is so developed that it can distinguish odors and that it may be possible to avoid odors that could be dangerous to itself. ..

In addition, the research team said, 'In the future, it is necessary to investigate how the reaction to the hummingbird's odor changes with learning and habituation,' showing motivation for future research.

in Science,   Creature, Posted by log1o_hf