These rodents lower the grass round their houses

Reduce your risks

Voles don’t eat this bundle grass, but they cut it to improve visibility around their burrows.

Photo by Zhiwei Zhong

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Trimming the grass around their homes might be a chore for many people, but for Brandt’s voles it’s a matter of life and death, new research shows. The small rodents are found in the grasslands of Mongolia, Russia and China, where they are regularly spotted trimming tall grasses near the openings of their burrows so they can watch the sky for predators such as shrikes, their main avian predator.

When shrikes fly around, Brandt’s voles use their teeth to chop down the grass in their native fields. But the rodents don’t eat the plant or bring it into their burrows, scientists observed. As a test, the scientists placed nets over the voles’ burrows to keep the shrikes from approaching – and the voles stopped cutting the grass.

The shrikes also appear to have adapted: they began to avoid areas where their hunting blanket had been mowed by the voles, the study found. His findings are a reminder of how a single species, no matter how small, can transform an entire ecosystem. – Anne Roth

Thrown grenades in Crusades?

In the Middle East, ceramic vessels in spheroconic shapes are common artifacts. Recent chemical analysis suggests that some were used as HE shells during the Crusades in Jerusalem in the 11th or 12th centuries.

Incendiary devices were not new. Archaeologists have found evidence of hand grenades in 12th-century Cairo, naphtha fire pots in 9th-century B.C. Assyria. and a chemical fireball found in 327 B.C. used against Alexander the Great – Adrienne Mayor

An example of early hand grenades: four of the terracotta grenades called “Greek fire” used by the defenders of Constantinople against the Turks in the late 15th century.

Photo by Erich Lessing, Art Resource, NY

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Hectares of aspen = one colossal tree

At more than 6,500 tons, a grove of aspens growing on 106 acres in Utah is the largest known terrestrial organism on earth by weight. What appear to be 47,000 individual trees are actually genetically identical stems that grow from one root system. Deer and cattle feeding on new aspen shoots threaten to kill this strange creature – a tree that has been its own forest for millennia. – Craig Welch

Although aspen trees appear to be individual trees, they are actually collections of genetically identical stalks, suckers shooting up from a single massive root system. This is located in Fishlake National Forest, Utah.

DIANE COOK AND LEN JENSHEL, NATIONAL GEOGRAPHIC CREATIVES

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These stories appear in the September 2022 issue of National Geographic magazine.