Squirrels are predictable

Somehow, the North American red squirrel can predict the cycle of food fluctuations. This animal often lays an extra litter in the spring of the bumper years to take advantage of the excess grain, scientists claim.

The conclusion is drawn from the 16-year study of Michigan State University scientists (USA). Their object of interest is the red squirrel ( Tamiasciurus hudsonicus ) in the Yukon forest, Canada.

Thick tangerine shell

The expert team used peanuts to take care of the traps and attach electronic chips to their bodies to monitor. After a certain amount of time, they try to catch the squirrels and check if the children are pregnant. They also recorded the number of cones on the spruce trees in the area. Seeds in the cones of spruce trees are the main food of red squirrels.

The number of cones produced in the autumn varies from year to year. For example, a tree only produces 10 cones this year, but can produce up to 500 hats the following year.

Red squirrel - Tamiasciurus hudsonicus (Photo: Newscientist)

"By 'laying out' a few hats for a number of years, the spruce pushes the grazing animals into food shortages, indirectly eliminating enemies," said Andrew McAdam, team leader.

Meet sharp nails

Cone of spruce.(Photo: answers.com)

North American red squirrels pair in January and give birth in March. In the years when spruce trees produce many cones, researchers find an interesting phenomenon: female squirrels will give birth to one more litter in the spring. of those years.

This means that red squirrels have somehow developed the ability to predict the reproductive laws of spruce.

"We often think that nutritious animals, such as red squirrels, are forced to follow the game of plants. This is the first evidence of the plant's ability to predict the reproductive cycle of an animal. " McAdam said.

The amount of excess grain in the fall is an important food source for young squirrels in the first months of life - the time when they are very vulnerable.

Experts are not yet clear why squirrels can predict that the number of spruce cones will decrease in a given year. McAdam said that this animal knows how to determine the concentration of certain hormones in cone buds on spruce. It is also possible that they know how to learn from observations. When many shoots are seen on spruce in the spring, the squirrels know that there will be plenty of food that year.

Viet Linh