If you ever are out and hear what appears to be a combination of a dog barking and someone being slowly murdered, then its it probably our very lovely Red Muntjac, or barking dear.
Above photo, a young male, with horns, and enlarged postorbital scent glands.
Yes, I know people who have been scared out of their wits by their strange call. They are very wary of humans - probably because they were hunted previously - and often you will hear them, but not see them. Their calls are both for mating and territorial, as well as when they see a predator (which can mean you).
The male has small, unbranched antlers which grow annually from a bony stalk on the top of the head. Here is one marking his territory by musking, using the large postorbital scent glands (see later photo). You can also see his protruding canines, which to me makes him look like a vampire deer….and despite their small size they can be quite fierce.
This species is omnivorous, feeding on grass, fruits, shoots, seeds, and birds' eggs, as well as small animals. It has also been known to scavenge, feeding on carrion. Here a female is looking for food.
Somewhat unique to the muntjac is the strong musculature of facial scent glands. They are the only species of deer to have frontal glands with a pair of slits on the face in line with the antler pedicles and possess a pair of massive pre-orbital glands. Males have larger glands than females which they use to mark the ground or in some cases other members of their species.
One of the best places to see them is Kadoorie Farm, where i have seen them wild and in their enclosure for the rescue animals/