A Group of River Otters Is Attacking People and Dogs in Alaska

“OTTER ALERT!” reads a bright yellow sign posted at the University Lake Dog Park in Anchorage, Alaska. The posting, complete with a svelte black silhouette of the offending aquatic mammal, goes on to explain that on September 20 a group of river otters “attacked dogs and bit a person near the lake,” reports Zachariah Hughes of the Anchorage Daily News.

The injured party was a woman who quickly intervened to save her dog from the onrush of aggressive otters. Later that same day, otters bit another dog at a different area of the same lake, according to a statement from the Alaska Department of Fish and Game (ADFG), quoted by the Daily News.

This pattern of otters on the attack around Anchorage began in early September when a nine-year-old boy was bitten several times at an East Anchorage duck pond. As Samantha Davenport reported for the Daily News at the time, the boy was taking video of the otters when one peeled off from the group and came straight for the boy and his older brother. As the brothers fled, the nine-year-old stumbled and when he fell, the otter delivered bites that punctured his legs and foot, per the Daily News.

ADFG officials are asking locals to exercise caution if they’re near rivers, creeks and streams in light of the attacks, according to reporting from the Associated Press. This event isn’t the first time river otters have acted aggressively toward humans and their pets, but it’s not considered common, per the AP. Officials are currently investigating whether the incidents all involve the same group of otters.

David Battle, a ADFG biologist, tells Ben Turner of Live Science that he thinks it could very well be just one ornery cadre of otters, which typically live in groups.

"There always seem to have been four or five otters involved in all the incidents," Battle tells Live Science. "Considering the rarity of this behavior in otters, and the fact that our first reported attack was in 2019 and it’s happened several times since then, this is very likely one group that has stayed together for a while or that come together frequently over a period of time."

In a statement quoted by the AP, ADFG says “because of the risk to public safety, efforts will be made to locate this group of river otters and remove them. Care will be taken to only remove the animals exhibiting these unusual behaviors.”

Battle tells Live Science that even if ADFG is able to determine whether one group of otters is the culprit, tracking the animals down will be no easy task. That’s because otters don’t have defined territories and may periodically take to the land to trot from one body of water to the next.

In the event that officials find a group of otters exhibiting signs of aggression towards people and dogs, they intend to remove one individual at a time and to test it for rabies after euthanasia, per the Daily News. In this case, ADFG tells the Daily News, relocating the animals is not a viable option since it would just move the threat posed by the otters to a new locale.

Alex Fox | | READ MORE

Alex Fox is a freelance science journalist based in California. He has written for the New York Times, National Geographic, Science, Nature and other outlets. You can find him at Alexfoxscience.com.