Cinnamon Hummingbirds Suck Nectar by Timer
Cinnamon hummingbirds (Selasphorus rufus) know when they last nibbled on which flowers, British scientists have found. The birds can do this even in areas with a bewildering abundance of flowers.
Susan Healy from the University of Edinburgh had observed in laboratory experiments that cinnamon hummingbirds regularly fly to flowers that replenish the nectar in their blossoms. She suspected that the animals have a pronounced sense of time for the replenishment rhythm of the flowers. She and her team then studied the phenomenon on free-living cinnamon hummingbirds in the Canadian Rocky Mountains.
It was shown that the hummingbirds can remember the time of their last visit to eight different flowers for one day. It seemed as if the animals followed eight independent internal timers, which they started when they left the flowers and reset to zero when they next stopped to drink.
This ability allowed the cinnamon hummingbirds to plan their foraging and thus save energy: if they had returned to a flower too early, there would not have been any new nectar. If you visit too late, on the other hand, there is a risk that other animals have already enjoyed themselves.
It was already known that animals in captivity learn to estimate time intervals from a few seconds to an hour and a half. However, the fact that the birds in the wild were so good at measuring time surprised the scientists.