Researchers discover unusual co-operation between species in
competition for scarce vegetation in northern mountain areas.
Who would have thought that two very different species, a
small insect and a furry alpine mammal, would develop a shared food arrangement
in the far North?
University of Alberta researchers were certainly surprised
when they discovered the unusual response of pikas to patches of vegetation
that had previously been grazed on by caterpillars from a species normally
found in the high Arctic.
U of A biology researcher Isabel C. Barrio analyzed how two
herbivores, caterpillars and pikas, competed for scarce vegetation in alpine
areas of the southwest Yukon. The caterpillars come out of their winter cocoons
and start consuming vegetation soon after the snow melts in June. Weeks later,
the pika starts gathering and storing food in its winter den. For the
experiment, Barrio altered the numbers of caterpillars grazing on small plots
of land surrounding pika dens.