September 12, 2016
Ground squirrels use information
on the position of the sun when hiding their food and reuse this information to
find their food stash again. The position of the sun serves as a reference
point for the animals, which live in southern Africa, to orient themselves and
adjust the direction they are traveling in. A study published by researchers
from the University of Zurich sheds new light on the old question as to how
animals find their bearings within their environment.
Jamie Samson and Marta Manser
from the Department of Evolutionary Biology and Environmental 1Studies at UZH
studied colonies of Cape ground squirrels (Xerus inauris) in the wild at the
Kalahari Research Center in South Africa. The diurnal rodents temporarily store
their food reserves
in several hiding places. As their habitat is very arid and sparsely vegetated,
points of reference in the environment, such as trees or bushes, are few and
far between. The UZH researchers have now discovered how the social rodents
orient themselves to find their way back to their temporary food stashes.
"The squirrels probably use the position of the sun as the most important
cue to roughly adjust their direction of movement," explains Samson.
Position of the sun as a rough
guide
The behavioral biologists gave
the ground squirrels food to hide. The direction in which the rodents bolted with
their spoils was recorded with the aid of GPS points. The striking thing was
that the animals moved in an almost straight line either towards or away from
the sun to find a suitable hiding place. Every time, the horizontal angle of
their direction of movement deviated slightly from the direction of the sun.
"Based on this movement pattern," interprets Samson, "we presume
that Cape ground squirrels use the position of the sun at a particular time of
day as a rule of thumb to find their bearings when searching for a place to
hide their food."
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