Wolves howl and whimper, but rarely bark. Their howling is described as haunting by some, mournful by others who have heard wolves in the wild. Distinguishing a wolf from a coyote or dog is difficult, especially when lighting is dim, the sighting is brief, or the animal is at a great distance. In general, an adult wolf is much larger than a coyote. Coyote colors rarely vary, while wolf colors vary widely and solid-colored wolves are not uncommon.
People sometimes breed wolves with dogs, creating wolf hybrids that can be mistaken for wolves.
Their wolf-like appearance may cause people to erroneously report wolf sightings. Attacks by wolf-dog hybrids on people and livestock may lead people to expect similar behavior from wild wolves and hamper wolf recovery. Hybrids seldom survive long in the wild. A wolf has very well developed senses. It can hear a rodent moving under heavy snow cover and other wolves howling from several miles distant.