Colour cues facilitate learning flower refill schedules in wild hummingbirds

摘要

Free-living hummingbirds can learn the refill schedules of individual experimental flowers but little is known about what information they use to do this. Colour cues, in particular, may be important to hummingbirds when learning about rewarded flower properties. We investigated, therefore, whether colour cues facilitated the learning of flower refill schedules in wild, free-living rufous hummingbirds (Selasphorus rufus). In the Cued condition, we presented birds with an array of six flowers, three of one colour, each of which were refilled 10 min after being emptied by the bird and three of a different colour, which were refilled 20 min after being emptied. In the Uncued condition we presented birds with six flowers of the same colour, three of which were refilled after 10 mm and three of which were refilled after 20 min as for the birds in the Cued condition. In the second part of the experiment, we moved the array 2 m and changed the shape of the array. Across both phases, birds in the Cued condition learned to discriminate between 10 and 20-min flowers more quickly than did the birds in the Uncued condition. The Cued birds were also better at discriminating between the two distinct refill intervals. Colour cues can, therefore, facilitate learning the refill schedules of experimental flowers in these birds.