Study: Prairie Dogs Are Fluffy Little Serial Squirrel Killers

Prairie dogs are adorable, yes, but they'd rip your brain out in a sweet second if they were big enough. Such is the conclusion we've drawn from a new study on prairie dogs' homicidal behavior. Researchers observed the critters for a handful of years and during that time discovered the brutal, coldly practical skeleton in a prairie dog's closet: it hunts down and kills baby squirrels so its own offspring can grow up fat and happy.

The behavior is startling because prairie dogs are herbivorous little rodents, and herbivorous creatures aren't known for violently and systematically destroying their neighbors in order to keep the food supply plentiful. In fact, researchers say this is the first instance of such behavior being observed in herbivores.

The study, which is co-authored by University of Maryland Center of Environmental Studies' John Hoogland, details a mystery and a horrifying revelation — in fact, Hoogland describes it as "just staggering." Back in 2007, Hoogland observed a white-tailed prairie dog shaking to death some little rodent, which he thought at first was some other prairie dog's baby (apparently it's a totally normal affair for prairie dogs to kill off other prairie dogs' babies).

After the deed was done and the prairie dog was gone, Hoogland got a look at the rodent corpse and discovered it was a ground squirrel, a local species that feeds on the same foods as prairie dogs. This prompted Hoogland and his team to begin observing the murderous ways of white-tailed prairie dogs, doing so to see if they targeted other squirrels or if this was a one-time fluke over some unpaid rodent debt.

It wasn't a fluke, though. Over the next half-decade, the team observed a total of 101 ground squirrel assassinations and found evidence of another 62 cases. Both male and female adult prairie dogs were observed killing the squirrels, and the murders started in May when baby ground squirrels would emerge from their neonatal slumber to forage for the first time.

In a statement to Gizmodo, Hoogland said:

Prairie dogs will chase ground squirrels—usually babies—and if they catch them, they shake them violently. While they're shaking, they're biting the back of the neck to sever the vertebral column. Sometimes they grab by the head and literally de-brain the baby. It's violent, savage, and awful.

The prairie dogs do not eat the squirrels they kill — instead, they leave the bodies out for scavengers to find and eat. The murders are purely for competitive reasons — the researchers found that such homicides are essential for the survival of prairie dog offsprings, ensuring there's enough food to keep the litters healthy and alive, even if it does come at the expense of the squirrel population. Researchers will continue to look into the matter, though, to try to determine specific factors that may trigger the murder sprees.

SOURCE: National Geographic