- The birds create a ‘3D body map’ to hover near a flower with surgical precision
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The mystery of how hummingbirds float in the air without bumping into flowers has been solved by scientists.
The birds have an ‘acute sense of touch’, which allows them to detect changes in air pressure caused by objects.
The tiny birds create a 3D body map when neurons in the brain ‘fire’ when gusts of air hit their wings, the findings show.
Although hummingbirds’ flight mechanisms have previously been studied in detail, much less is known about how their sense of touch helps them drink nectar from a flower without bumping into it.
The new research focused gentle puffs of air at the birds while measuring their brain activity using electrodes.
Hummingbirds’ “acute” sense of touch helps them linger near a flower to feed without bumping into it. Pictured is a Blue-chinned Sapphire Hummingbird (Chlorestes notata) feeding on a wild Lantana flower
They found that hummingbirds create a 3D map of their bodies when neurons fire in two specific places in the forebrain – as air blasts hit the feathers on the leading edge of their wings and the skin of their legs.
They discovered that the intensity of air pressure, influenced by factors such as proximity to an object, is picked up by nerve cells at the base of feathers and in the leg skin and transmitted to the brain, which determines the body’s orientation relative to an object. measure object. .
Most of what scientists know about how touch is processed in the brain comes from studies in mammals, but bird brains are very different from mammalian brains.
The study was led by experts from the University of California, Los Angeles and published in Current Biology.
Study corresponding author Professor Duncan Leitch said: ‘In mammals we know that touch is processed across the outer surface of the forebrain in the cortex.
The tiny birds create a 3D body map when neurons in the brain “fire” as air blasts hit their wings, the findings say. In the photo a young male Rufous Hummingbird (Selasphorus rufus)
Image shows the two parts of the hummingbird’s forebrain that process touch. One region processes touch to the head and face, and the other processes touch the rest of the body. This allows the hummingbird to create a 3D map of its body so it can orient itself in space during flight
‘But birds have brains without a layered cortex structure, so it was a wide open question how touch is represented in their brains.
‘We showed exactly where different types of touch activate specific neurons in these regions and how touch is organized in their forebrain.’
The work adds to knowledge about how animals perceive and navigate their world and could help identify ways to treat them more humanely, the team said.
There are more than 350 species of hummingbirds, which live exclusively in the Western Hemisphere, from Alaska to the tip of South America.
A 2020 study found that they owe their colorful iridescent plumage to ‘pancake-like’ cells in their feathers that reflect light like a soap bubble.
Other research has found that hummingbirds can identify at least eight colors that are invisible to humans thanks to an extra light-sensitive cone in their eyes.