Here’s what triggers giant honeybees to swarm

Huge honeybees send undulations across open nests, flipping their abdomens upwards in coordination, seemingly avoiding the sight of approaching predators. A new study reveals details about what makes a behavior striking, known as flashing.

That blink is strongest when bees are shown a dark object moving against a bright background under bright ambient light, researchers report in Sept. Journal of Experimental Biology. A verbal experiment simulates animals like hornets, one of the predators of bees, flying against a bright sky, and shows what visual cues tell behavioral researchers.

The behavior “may be learned in the way that an animal species communicates with another to be able to defend itself,” says Kavitha Kannan, a neurobiologist at the University of Konstanz in Germany, who was not involved. study

Including giant honeybees Dorsal bee, they typically form open nests from other materials in places such as tree branches and exposed window sills. In the new study, researchers worked with two people A. dorsata they nest in the rafters. Standing near the beehives, ecologist Sajesh Vijayan moves pieces of cardboard of various sizes in shades of gray and black against a background of either gray or black. The bees trembled when the black object moved against the gray drop, but not when the contrast was flipped.

It’s likely that the black-on-dog “likes a natural predator or a natural condition,” says Sajesh, who goes by his first name, as it is common in many parts of southern India. “These colonies are open nesters, so they are always exposed to the bright sky.”

The team observed a little flickering during the dark twilight, morning and evening time. Since flashing is a response to being perceived as unwelcome by an abductor or by another visitor, such as a bee from another colony, the researchers hypothesize that other defensive mechanisms may be at play in dark conditions.

“We also think that flashing is a special response to hornets, which has not been reported in cases of birds attacking or birds flying past these colonies,” says Sajesh. Birds, on the other hand, elicit a stinging mass. This is possible because approaching birds in the visual field of comparatively large bees flee, and at that point the behavior of the bees can be “no longer taking chances, like a sting,” says Sajesh.

In both hives, the flickering completely disappeared when the bees stopped at the smallest objects, this one a circle four centimeters in diameter. The results suggest that there is a minimum threshold size that triggers the circles.

The strength of the meridians did not decrease even when the bees were repeatedly exposed to artificial means, perhaps because it is advisable to remain on guard against predators as the hornets make constant attacks.

It is not yet known how exactly the bees perceive the objects in the study. “They might actually see this object moving, or respond to a reduction in the visual field,” Sajesh says.

The researchers plan to explore this question further. They also design experiments with led screens to visualize the colors of the background and the shapes and objects they envisage to provide material for the types of shapes and even movements of the bees.