Wolves prefer the night to avoid encountering this animal
From Earth.com:
A large field experiment across 425 square miles in northern Poland shows a simple truth. Wolves fear humans more than anything else they encounter during their lives. Researchers hid camera and speaker units in the forest and let wildlife trigger them. Calm human voices made wolves bolt more than any other sound.
Lead researcher Liana Zanette from Western University, along with other colleagues, designed the test to measure fear, not curiosity. The team compared reactions to humans, dogs, and harmless bird calls.