Jackals, Wolves, Coyotes and Foxes and the Violet Gland

 Despite their size difference there are many traits that foxes, wolves, coyotes and Jackals have and one is a scent gland in the tail. The Violet gland.

showing location of the Violet gland on the coyote tail -same position as on foxes, wolves and jackals 

Violet Gland on a wolf

On the fox. These glands show up more clearly in infra red night time photos

The violet gland is also known as the supracaudal gland. It is found on the upper surface of the tail but the gland is less developed in jackals than in other canids, such as foxes and wolves.  The gland produces a mixture of volatile terpenes that are similar to those produced by violets, which is how it got its name. The chemicals produced by the gland are released in much greater quantities than in flowers, and the resulting smell can be unpleasant. 

The violet gland is used for scent marking and intra-species signaling. Olfactory cues from the violet gland, along with other glands, play an important role in social interactions between canids. 

If you have foxes  moving through your garden or that pass through your area then you will be familiar with their smell which sometimes seems to annoy, irritate or interest domestic dogs!