One study claims hummingbirds can order things in sequence, but researchers say it doesn't confirm they can count.
Hummingbirds are not only bright in appearance but also in brain, apparently, with new research suggesting that the little creatures are capable of grasping a numerical concept of order.
While hummingbirds have previously been found to visit flowers in particular sequences when searching for food, the researchers say the new study suggests that this process could be based on the concept of "first," "second," etc., rather than characteristics such as the specific location of the flower or nearby landmarks.
However, it does not mean that hummingbirds can count.
"Counting has a more anthropocentric connotation," said Dr. Maria Tello-Ramos of the University of St Andrews, a co-author of the study. “This is more like ordering things in a sequence. We can't say that the hummingbirds were counting, 'One, two, three, four,' but they knew that the fourth flower was different from the third flower they found, ”he said.
Tello-Ramos added that such a skill could help hummingbirds attach information to their foraging sequence, such as that the second flower has run out of nectar, meaning they know how to skip it, even if it looks unchanged, and move on. to the next in sequence.
It has previously been discovered that some other animals that have received training, such as rats, monkeys, bees and parrots, can understand that the elements in a sequence can take a particular order based on an abstract number concept.
However, the team behind the new research said their study was the first time such an ability had been demonstrated in a wild, free-living vertebrate.
Writing in the Proceedings of the Royal Society B, Tello-Ramos and his colleagues reported how they made their discovery by presenting nine male rufous hummingbirds with a row of 10 identical false flowers on sticks spaced 20 cm apart, with each flower constructed from of a foam disc with a tube in the center.
To train the hummingbirds, the team filled the inner tube of the first fake flower in the row with a sugar solution. Once each hummingbird visited this flower four times in a row, the flowers were shuffled, to account for the subtle differences between them, and the first flower in this new row was filled with a sugar solution.
The training was repeated with the sweet treat on the second, third and finally the fourth flower. The team found that all of the hummingbirds learned to fly to the correct flower, and the one containing the sugar visited significantly more than would be expected by chance during training.
To check that the birds not only learned which flower to choose by its distance along the row, the team presented the birds with a row of randomly spaced fake flowers. The results show that the birds had a clear preference for flying directly to the flower containing the sugar solution.
Tello-Ramos said the findings added a numerical concept of order to a growing list of information hummingbirds use to survive, including the location and color of flowers. "If the information is relevant, the hummingbird will use it," he said.