Voles cut grass to watch flying predators

Date:
March 11, 2022
Source:
University of Exeter
Summary:
A tiny rodent trims tall grasses so it can watch the skies for
flying predators, new research shows. Brandt's voles live in
grassland in Inner Mongolia, China, where they are hunted by birds
called shrikes.



FULL STORY ==========================================================================
A tiny rodent trims tall grasses so it can watch the skies for flying predators, new research shows.


========================================================================== Brandt's voles live in grassland in Inner Mongolia, China, where they
are hunted by birds called shrikes.

The new study -- by the Institute of Zoology, Chinese Academy of Sciences; Northeast Normal University of China and the universities of Exeter
and Florida -- found that the voles cut tall bunchgrass when shrikes
are nearby.

The voles don't eat or use the bunchgrass -- they cut it to keep
themselves safe, an example of "ecosystem engineering." "When shrikes
were present, the voles dramatically decreased the volume of bunchgrass,"
said Dr Dirk Sanders, of the Environment and Sustainability Institute
on Exeter's Penryn Campus in Cornwall.

"This led to fewer visits from shrikes -- which apparently recognise
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." The researchers
also tested the impact of keeping birds away, by putting up nets over
certain areas.

With no shrikes overhead, the voles stopped cutting the bunchgrass.

"We sometimes underestimate the ability of wild animals to react to
changes in their environment," Dr Sanders said.

"In this case, the voles were able to change their behaviour in response
to the removal of predators." He added: "Our findings are a reminder that species show remarkable adaptations. It also underlines that the loss of
even a single species in a food web can result in unexpected changes to
an entire habitat." "This study provides a good example that animals can actively modify their habitat to reduce predation risk," said Dr Zhibin
Zhang, from the State Key Laboratory of Integrated Management of Pest
Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences.

Dr Zhiwei Zhong, from Northeast Normal University, added: "The finding
would have some implications in rodent management in pasture land. Keeping
or planting these large bunchgrasses may help to attract shrikes, and
then to reduce the population density of voles."

========================================================================== Story Source: Materials provided by University_of_Exeter. Note: Content
may be edited for style and length.


========================================================================== Journal Reference:
1. Zhiwei Zhong, Guoliang Li, Dirk Sanders, Deli Wang, Robert D. Holt,
Zhibin Zhang. A rodent herbivore reduces its predation risk
through ecosystem engineering. Current Biology, 2022; DOI: 10.1016/
j.cub.2022.02.074 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2022/03/220311115346.htm

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