How the Gray Wolves Survived when the World Froze

11,000 years ago, the last Ice Age wiped out several species around the world. The change in climate brought about scarcity of food for wildlife. An extinction event happened so quickly in a short geologic time scale, causing one-third of all existing species to disappear.

Although a new ecosystem immediately emerged right after, some species survived the catastrophic event which is mass extinction. One of them being the gray wolves.

Gray wolves are one of the largest predators that survived the last Ice Age. At this time, they can be found roaming around Yukon's boreal forest and tundra, and said to prey on caribou and moose as their main sources of food. The main question is, how did the gray wolves make it through?

Diet pattern predicted through wolf bones

The Palaeogeography, Palaeoclimatology, Palaeoecology study, led by museum palaeontologist Dr. Danielle Fraser, studied and analyzed teeth and bones of wolves, and said that they may have survived the last Ice Age by adapting through their diet.

The evidence preserved in wolves' teeth and chemical traces in their bones, which were collected in Yukon and curated in the museum's national collections, enabled the researchers to determine their eating pattern, as well as the change in their diet. Their tooth and isotope analysis revealed that wolves shift prey availability, allowing them to thrive.

Landry, the lead author who completed the work as a Carleton University student and supervised by Fraser, explained how the specimen determined how the animal ate, and what the animal was eating throughout its life, up until about a few weeks before it died.

Through the microscopic wear patterns on wolf's teeth, researchers were able to establish models on the wolves' eating behavior. The study was based on 48 wolves- 31 of them coming from ancient beasts from 50,000 and 26,000 years ago, and 17 came from modern wolves, whose skulls had been preserved in the Canadian Museum of Nature's Zoology Collection.

The marks on the teeth revealed what kind of prey the wolves fed on. Scratch marks indicates that they consumed on flesh, and presence of pits suggests chewing and gnawing on scavenger's bones.

Findings confirmed that teeth from both ancient and modern wolves showed scratch marks, which means they originally were able hunt preys and feed on their flesh, rather than feed on other predator's leftovers.

Isotope Analysis identified wolves' prey

This is where Isotope analysis takes place. Wolves as predators are definitely categorized as a carnivore. In isotope analysis, stable isotopes are taken up into plants from soil. Isotopes normally enter an animal's teeth and bones when it is eaten, specifically by herbivores. When these herbivores are eaten by wolves, they will obtain the said isotopes, which us why during analysis, the prey they feed on was identified.

Results showed that about half of the gray wolf diet came from horses, which went extinct during the Pleistocene. About 15% came from caribou and Dall's sheep, with some mammoth mixed in.

The study generally implicated how gray wolves' flexibility to adapt to climate change and shift their habitat to prey on available species accounted their survival.