The mystery of the hummingbird, unveiled with videos of high speed - ABC.es | CajalesyGalileos

The use of artificial flowers and high-quality video speed has allowed scientists to get interesting information about the intimate relationship between hummingbirds and pollinating flowers. A study published in the British ecological journal "Functional Ecology" was the first to measure the amount of energy that hummingbirds use while feeding on flowers.

Hummingbirds are among the most colorful and small birds on Earth and are also important pollinators of flowering plants in America. The flowers pollinated by hummingbirds are generally red in color, tubular and usually have no odor, as the ecologists have described. However, they have a big question: Why do most of the flowers pollinated by hummingbirds hang vertically?

A group of scientists from the University of California, Berkeley built a habitat of artificial flowers that pointed in different addresses. That is, some were placed horizontally, others inclined at 45 degrees or vertically down. These were provided with a nectar that fed the birds . They worked with hummingbirds of the Calypte Anna species, one of the most common on the campus of this university.

Researchers recorded high-speed video with hummingbirds while feeding on nectar of these artificial flowers, and thus they observed how the position of the plant affected the position of the bird and the movements to which it submitted its body in the heat of flight. Then they recorded, thanks to masks, the amount of oxygen consumed by the hummingbird during feeding .

"The flowers have evolved to attract pollinators. Almost all the flowers pollinated by hummingbirds hang vertically, so our hypothesis was that they developed in this way because hummingbirds would have to use less energy to feed, but we found the opposite , since < It is more costly in terms of energy for hummingbirds to feed on those flowers, "says researcher Sapir.

In evolutionary terms, this means that other factors must be at play. "Our findings suggest that other factors may be dictating flower orientation. The flowers may be excluding less efficient pollinators, such as insects. And horizontal flowers are more exposed to rain, which can dilute the amount of nectar in a flower. We know that hummingbirds can detect how nectar is sweet and that may be why they select downward-facing flowers because they know their nectar has more sugar, "says Sapir.

mystery of the hummingbird, unveiled with high-speed videos - ABC.es.

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