Really none, a bear would kill a wolf if the wolf came near its den and cubs or food.
Wolves don't naturally have any, except humans. Bears will attack a wolf if it feels threatened not sure if this is true but with all the research and reading I've done, I'm pretty sure.
humans
i think man kind is their predators
Literally to say there are no predators for wolf but in some cases wild cats hurt them especially during having their meal,if these wolf interrupt then this scenario happens
ducks have many predators two of them is a wolf and fox
A wolf and a bear.
There are no significant predators of wolves. Some animals, primarily bears, will fight with wolves, but they don't hunt them for food.
Man and bears
cougar,wolf and bear
The Arctic wolf is pretty much the apex predator and has not predators itself.
The Arctic wolf is an apex predator and has no natural predators.
Predators to the moose.
smelling for moose and listening for predators