You don’t have to be an ornithologist to be impressed by the long migration route of the tiny Rufous Hummingbird. Rufous Hummingbirds have been documented to fly as far as 6,200 kilometres from Alaska to Mexico and back, every year (Calder and Healy, 2006). This fact has prompted scientists to ask how these birds remember where to go, and how much cognitive ability they have. In recent research there have been many studies on the subject of hummingbird cognition and their ability to remember where to feed, despite being so small (Henderson, et al., 2006; Hurly, et al., 2010; González-Gómez, et al., 2011; Jelbert, et al., 2014).

Henderson, et al., (2006) trained Rufous Hummingbirds to feed from either a flower positioned higher or lower, then presented them with two identical flowers spaced 20 centimetres (cm) apart. The researchers wanted to see if the trained birds would go to the flower closest to them regardless of their training, or go to the one more similar to  the position of the feeder they had been trained to go to, regardless of which would be the shortest distance to travel to. Studies like this have been done before, using arrays of flowers in the x–y dimension (Healy and Hurly, 1998; Henderson, et al., 2001), but Henderson, et al., (2006) wished to demonstrating the ability of hummingbirds to learn spatial relationships in the z dimension. The hummingbirds were trained in their own habitats. They found that hummingbirds were more likely to feed from the flower at a similar height to the flower they had been trained to visit, regardless of which route would be the least amount of effort (Henderson, et al., 2006).

A 2010 study tested whether hummingbirds use visual beacons to remember specific locations (Hurly, et al., 2010). For example, it is assumed that pollinators like bees and hummingbirds use the bright colours of flowers to guide them towards food; this is the reason hummingbird feeders are bright red. However, it has  been reported that hummingbirds return to feeder locations after migrating even when the feeder is not out. Hurly, et al., (2010) tested whether they could use visual beacons to guide hummingbirds to a new feeding location after learning an original feeder location. All of the birds in Hurly, et al.‘s study were trained in their natural habitat; no birds were handled and all chose to come to the feeders on their own. Remarkably, Hurly, et al. (2010) found little evidence that hummingbirds use distant visual beacons to remember where their food is. Instead, they would approach the original feeders location (within 70 cm) and would not fly directly to the new feeder. These results suggested that hummingbirds learn surrounding landmarks to remember the location of feeders, then use the colour as confirmation (Hurly, et al., 2010).

Data was recorded in terms of the hummingbirds choice being the first artificial flower they tried to feed from. The four positions of the flowers on each board indicated different combinations of integrated thought. Jelbert, et al. (2014) scored each hummingbirds’ choice based on the three conditions for episodic-like memory (For example, one choice would indicate correct ‘where’ and ‘which’, incorrect ‘what’, the correct choice would indicate all three correct, and so on).  In the experiment, the hummingbirds were able to combine the information presented to locate the correct flower in both types of boards. Not only did they integrate this information, but they did it in a natural environment, combined with other behaviours like mating, attacking intruders (of course), catching insects, and feeding from surrounding natural flowers.

This latest experiment by Jelbert, et al. (2014) was the first time this type of integrated memory has been demonstrated in free-living, wild birds and demonstrates some pretty remarkable cognitive ability in the Rufous Hummingbird. It also suggests there may be more cognitive abilities of birds that we are unaware of. More research conducted on free-living, wild birds as in Jelbert, et al., (2014), Hurly, et al. (2010), and Henderson, et al. (2006) should be encouraged to eliminate any bias inflicted on results by laboratory conditions, and to avoid the handling of fragile hummingbirds when it is not necessary.

Literature Cited

Calder, W. A., and Healy, S. 2006. Rufous Hummingbird. The Birds of North America Online (A. Poole, Ed.) Ithaca: Cornell Laboratory of Ornithology; Retrieved from The Birds of North America Online database: [link]

Clayton, N. S., Griffiths, D. P., Emery, N. J., and Dickinson, A. 2001. Elements of episodic-like memory in animals. Philosophical Transactions of the Royal Society B. 356: 1483-1491. [link]

González-Gómez, P. L., Vásquez, R. A., and Bozinovic, F. 2011. Flexibility of foraging behaviour in hummingbirds: the role of energy constraints and cognitive abilities. The Auk 128: 36-42. [link]

Healy, S. D. and Hurly, T. A. 1998. Rufous hummingbirds’ (Selasphorus rufus) memory for flowers: patterns or actual spatial locations? Journal of Experimental Psychology: Animal Behaviour Processes 24: 396-404. [link]

Henderson, J., Hurly, T. A., and Healy, S. D. 2001. Rufous hummingbirds’ memory for flower location. Animal Behaviour, 61: 981-986. [link]

Henderson, J., Hurly, T. A., and Healy, S. D. 2006. Spatial relational learning in rufous hummingbirds (Selasphorus rufus). Animal Cognition 9: 201-205. [link]

Hurly, T. A., Franz, S., and Healy, S. D. 2010. Do rufous hummingbirds (Selasphorus rufus) use visual beacons? Animal Cognition 13: 377-383. [link]

Jelbert, S. J., Hurly, T. A., Marshall, R. E. S., and Healy, S. D. 2014. Wild, free-living hummingbirds can learn what happened, where and in which context. Animal Behaviour 89: 185-189. [link]