The researchers created a mock flower bed on a perspex sheet containing several small feeding wells filled with 'nectar' - sucrose solution of varying quantities and concentrations. Coloured paper, to imitate petals, was placed around the feeding wells. The colour of the petals indicated the make-up of the nectar concentration and volume of the nectar contained in the flower.
Under normal circumstances, hummingbirds prefer flowers containing sweeter or larger volumes of nectar, as this provides them with more energy.
However, the introduction of decoys altered their choices, making another, 'target' flower seem more attractive. Preference for the target flower increased, regardless of nectar volume or concentration.
Dr. Bateson, a member of the Evolution and Behaviour Research Group at the University, said:
"This research shows that the birds, like humans, are actually more irrational than we previously thought. They are prepared to make an instant decision based on the choices they have available at the time.
"Until now experts thought that birds would compute which source of food was going to provide them with the maximum amount of energy, taking variables such as volume and concentration into consideration, but our research suggests that, like humans, hummingbirds can be influenced by the range of options available."
"The findings have implications for a wide range of biological problems involving animal decision-making. For example, choice tests are regularly used in animal welfare research to determine conditions preferred by captive animals, but the current findings suggest that t
Contact: Melissa Bateson
University of Newcastle upon Tyne