Strange memory of hummingbirds

Although the brain is only as big as a grain of rice, hummingbirds have superior memory when it comes to food, a new study has just revealed.

These tiny creatures weigh only 20 grams or less and feed on nectar and insects.

Red-headed hummingbirds.( Photo: Rshantz )

The study, published in Current Biology, suggests that they not only remember where the food is, but can plan with a certain accuracy.

" For us, this is the first evidence that wildlife can remember both the location of the food source and the time it was visited ," said Susan Healy, of the University of Edinburgh.

Healy and colleagues in the UK and Canada studied red-headed hummingbirds in mountainous Canada. They found that the birds remembered the location of each specific flower and the last time they came to cup there - two aspects of segmented memory that were considered to be unique to humans.

Scientists have calculated how often hummingbirds visit 8 artificial flowers filled with sucrose in the bird's feeding grounds.

With half of the flowers, they filled the sugar again after 10 minutes and 20 minutes with the other half, after the flowers were removed.

The birds return to visit these "gallbladder" as scheduled: with flowers filled every 10 minutes, they will visit sooner.

" We were surprised because their planning ability was so good and that they were trying to get the most out of eight different flowers, " Healy said.

Scientists surmise that hummingbird brains thrive so much because they have to program long-term flights, and they don't need to spend time and energy searching for food. On average, red-headed hummingbirds migrate through 3,219 km in winter from Canada to a warmer place in Mexico. In the spring, they return home to breed.

T. An