A calf that apparently lost its mother in Grand Teton National Park has picked an unlikely replacement: a massive bull moose nearly twice its size, who it now follows "like a puppy dog."

  • Sighting location: Gros Ventre Campground, Grand Teton National Park, Wyoming
  • Moose calves are typically born in spring after an 8-month gestation, putting this one at roughly 5 to 6 months old
  • Precedent: a Yellowstone grizzly bear was seen adopting extra cubs in 2024, swelling her litter to five
  • Adoption by a bull, rather than a female, is described by biologists as "fairly strange"

Wildlife watchers first noticed the odd pair hanging around the campground in late October and early November. The calf sticks close to the bull's side, rarely straying more than a few yards.

A Puppy-Like Bond, With One Exception

"The calf follows him (the bull) around like a puppy dog," wildlife watcher Jonathan Raetzman told Cowboy State Daily. "The two are never more than a few yards apart, it seems."

The bull tolerates almost everything from his adopted companion — except attempts to nurse. Photographer Tim O'Leary said the bull "wouldn't really kick it hard, but it would try to nudge it away" whenever the calf tried.

Nobody knows what happened to the calf's biological mother. Raetzman said he's confident it wasn't a collared cow moose that was recently found poached near Dubois, a separate and unrelated case currently angering local hunters.

Why a Bull, Not Another Cow?

Female moose, elk and other ungulates will sometimes adopt orphaned young from other mothers, or babysit each other's offspring. A male taking on that role is far rarer.

"It's fairly strange for an orphaned calf to bond with a bull instead of trying to find another cow willing to adopt it," biologist Kevin Monteith of the University of Wyoming's Haub School of Environment and Natural Resources told Cowboy State Daily.

"Nutritionally, the calf can function off forage just fine. It just misses out on the learning it could gain from Mum."

Monteith said having any adult nearby to protect and guide it likely improves the calf's odds heading into a harsh Wyoming winter, even if that adult is an unrelated male.

Good Signs So Far

Observers say the calf already eats forage on its own, which both O'Leary and Raetzman have witnessed directly. Monteith agreed that's an encouraging sign the calf no longer strictly needs milk to survive.

The bull himself has drawn attention for his sheer size. O'Leary called him one of the larger bulls he's seen in the park, though not yet one of the Tetons' famously massive named bulls, like Hoback, Bondurant or Fremont.

Despite his bulk, the bull has been consistently gentle with his young charge. When a second, smaller bull was nearby, O'Leary noticed the calf always ran to catch up with the bigger bull instead, never the smaller one.

"It's a big calf. It looks to be healthy and in really good shape," O'Leary said.

Whether the arrangement lasts through winter remains to be seen. But for now, in a park better known for grizzlies and wolves grabbing headlines, an oversized bull moose quietly babysitting someone else's calf is drawing its own small crowd of admirers.