Some rodents may have something in common. Scientists have observed that voles trim the tall grass in their neighborhood to both maintain it and make it safer.
An international team of scientists studied the curious behavior of Brandt’s voles or steppe voles (Lasiopodomys brandtii), a rodent belonging to the Cricetidae family. The species is found in Mongolia and northern China. It lives in shrublands and grasslands.
The journal published the findings of the team. Current BiologyIt was noted that the voles were observed trimming tall native bunchgrasses (“Achnatherum splendens”) not for food but as a way to watch out for hungry flying predators called “shrikes”. Shrikes are sparrow-like, carnivorous birds belonging to the Laniidae Family. There are 34 species in four genera.
The paper’s authors have dubbed the behavior “ecosystem engineering.”
“When shrikes were present, the voles dramatically decreased the volume of bunchgrass,” said study co-author Dirk SandersResearcher at the University of Exeter. “This led to fewer visits from shrikes, which apparently recognize cut-grass areas as poor hunting grounds.
“An activity like this is costly for the voles in terms of energy, so there must be high ‘selection pressure’ to do it: cutting the grass must significantly improve their chances of survival.”
Researchers draped nets over the test areas and the voles stopped cutting bunchgrass because shrikes couldn’t swoop in on them as prey. “We sometimes underestimate the ability of wild animals to react to changes in their environment,” Sanders said.
The study revealed that voles can change their behavior to avoid predators and actively alter their environment. “It also underlines that the loss of even a single species in a food web can result in unexpected changes to an entire habitat,” said Sanders.
Zhiwei Zhong is the lead author of the study. According to Zhong, this study could have implications on managing rodent populations in pastures. “Keeping or planting these large bunchgrasses may help to attract shrikes and … reduce the population density of voles,” said Zhong.
“Given the ubiquity of predation risks faced by consumers and the likely ability of many consumers to alter the habitat structure in which they live, the interplay between predation risk and ecosystem engineering may be an important but unappreciated mechanism at play in natural communities,” the paper’s abstract stated.
Planting bunchgrass could be an alternative to rodenticides in controlling vole populations. A 1996 paper by Dale Nolte of Denver Wildlife Research Center, part of the U.S. Department of Agriculture, noted that Brandt’s vole is “the most widespread and the most detrimental rodent to the steppes of Mongolia,” harming crops and pastures. The paper showed that rodents are sensitive to zinc phosphide which can be ingested and transforms into toxic gas. The compound is usedAs a fumigant in grain storage.
Edited by Siân Speakman and Kristen Butler