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Water deer

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The water deer, known scientifically as *Hydropotes inermis*, is a unique small deer native to parts of China and Korea.

Gorani (Korean water deer) (Hydropotes inermis)
Gorani (Korean water deer) (Hydropotes inermis)

While most deer species are recognized by their large antlers, water deer are quite different because they lack these bony structures entirely. Instead, the males possess prominent, downward-pointing canine teeth known as tusks. Because of these unusual teeth, the animal is sometimes called a "vampire deer." Despite these strange physical traits, modern molecular analyses of DNA show that they are classified as cervids. Specifically, they are considered a sister taxon, or a very close relative, to the *Capreolus* genus.

The anatomy of the water deer is highly specialized for its environment.

They possess narrow pectoral and pelvic girdles, long legs, and a long neck. Their hind legs are longer than their front legs, which causes their haunches to sit higher than their shoulders. This body shape allows them to run using jumps similar to a rabbit. They also have a unique feature among all cervids: scent glands located in the groin of each leg. Their coat is typically a golden-brown color, though it becomes a thicker, coarser grayish-brown during the winter months. Fawns are born with white stripes and spots to help them blend into their surroundings.

The development and use of their tusks is a fascinating biological process. These canine teeth erupt in the autumn during a buck's first year, usually around 6 to 7 months of age. By early spring, the tusks have already reached about 50% of their final length. The roots of these teeth remain open until the deer is between 18 and 24 months old. Interestingly, the tusks are held loosely in their sockets and are controlled by facial muscles. A buck can actually draw the teeth backward to make eating easier. During territorial fights, a male will thrust the canines forward and pull in his lower lip to present a two-pronged weapon to rivals.

Taxonomy and naming provide insight into the animal's history and habits.

Chinese water deer Stuffed specimen 2
Chinese water deer Stuffed specimen 2

The genus name, *Hydropotes*, comes from the ancient Greek word for "water-drinker." This name likely refers to the deer's preference for living near rivers and swamps. The species name, *inermis*, is Latin for "unarmed" or "defenseless," which refers to their lack of antlers. Robert Swinhoe first described the species to the Western world in 1870. While they were once classified in their own subfamily, *Hydropotinae*, DNA studies of the mitochondrial control region and cytochrome b have placed them within the subfamily *Capreolinae*.

Water deer have a wide historical distribution that has changed over time. Archaeological evidence from the Pleistocene and Holocene periods shows they once lived in much larger ranges. This included areas like eastern Tibet, Inner Mongolia, the Japanese archipelago, and even northern Vietnam. Today, they are indigenous to the lower Yangtze River, coastal Jiangsu, and islands in Zhejiang. In South Korea, they are known as *gorani* and have a large population of approximately 700,000 individuals. In contrast, the Chinese subspecies is considered critically endangered. Some populations have even been introduced to the United Kingdom, where they reside near Woburn Abbey and Whipsnade.

Hydropotes inermis inermis Whipsnade Zoo (crop)
Hydropotes inermis inermis Whipsnade Zoo (crop)

The behavior of the water deer is largely solitary, except during the mating season. Males are highly territorial and use various methods to mark their boundaries. They may use urine, feces, or even dig small pits to release scents from interdigital glands on their feet. A male might also rub his preorbital glands against a thin tree by holding it in his mouth. When two males encounter one another, they often walk stiffly toward each other before walking in parallel to assess the rival. They are also excellent swimmers, capable of traveling several miles to reach remote islands in river systems.

Understanding the water deer requires looking at the complex relationship between the species and its environment. In South Korea, the population is thriving because natural predators like tigers and leopards have gone extinct. However, they are sometimes viewed as "harmful wildlife" because they can impact human property. In China, conservation is a major focus due to their endangered status. Even in the United Kingdom, scientists monitor them closely. Studies of the British population show lower genetic diversity than the native Chinese groups. This highlights the importance of protecting the original habitats of these unique, tusked deer.

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🖼️ Images & Media (4)
File:Gorani (Korean water deer) (Hydropotes inermis).jpg
Gorani (Korean water deer) (Hydropotes...
File:Hydropotes inermis inermis Whipsnade Zoo (crop).jpg
Hydropotes inermis inermis Whipsnade Zoo...
File:Chinese water deer (Hydropotes inermis) skeleton at the Royal Veterinary College anatomy museum.JPG
Chinese water deer (Hydropotes inermis)...
File:Chinese water deer Stuffed specimen 2.jpg
Chinese water deer Stuffed specimen 2.jpg
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