Wolves on an Alaskan island caused a deer population to plummet and switched to primarily eating sea otters in just a few years, a finding scientists at Oregon State University and the Alaska Department of Fish and Game believe is the first case of sea otters becoming the primary food source for a land-based predator.
Using methods such as tracking the wolves with GPS collars and analyzing their scat, the researchers found that in 2015 deer were the primary food of the wolves, representing 75% of their diet, while sea otters comprised 25%. By 2017, wolves transitioned to primarily consuming sea otters (57% of their diet) while the frequency of deer declined to 7%. That pattern held through 2020, the end of the study period.
“Sea otters are this famous predator in the near-shore ecosystem and wolves are one of the most famous apex predators in terrestrial systems,” said Taal Levi, an associate professor at Oregon State. “So, it’s pretty surprising that sea otters have become the most important resource feeding wolves. You have top predators feeding on a top predator.”
Read more at: Oregon State University
A wolf travelling and foraging in the intertidal zone on Pleasant Island in Alaska. (Photo Credit: Bjorn Dihle)