The Chinese water deer, a small species native to China and Korea, stands out within the deer family. It is known for a distinctive feature: prominent, elongated teeth, often called “fangs.” These dental structures have earned it the nickname “vampire deer.”
Unraveling the “Fangs”
The “fangs” of the Chinese water deer are elongated upper canine teeth. Unlike the true fangs of carnivores, these are not used for hunting prey or for consuming food. Instead of growing antlers, which are characteristic of most other deer species, male Chinese water deer develop these dental weapons. The canines can protrude significantly from the upper jaw, reaching lengths of up to 8 centimeters and are partially retractable. While both sexes possess canine teeth, those of the female are considerably smaller, typically measuring only a few millimeters and often not visible beyond the lip.
Purpose and Behavior
These canines serve a specific function, particularly for male Chinese water deer, known as bucks. During the breeding season, these tusks become instruments for establishing dominance, defending territories, and securing mating opportunities. Males engage in ritualized displays, which can include parallel walking, ear-slapping, head shaking, and vocalizations like chattering or “whickering.” These displays often serve as a warning, where the deer might snarl to emphasize the menacing appearance of their tusks, aiming to avoid direct physical confrontation.
When these displays are insufficient, bucks resort to direct combat, using their tusks to slash and stab rivals. They typically aim for vulnerable areas such as the flanks and neck. While these fights can be intense and often result in serious injuries, fatalities are less common compared to battles between antlered deer. The tusks are further accentuated by a dark patch of fur behind them, which helps to draw attention to these weapons.
Evolutionary Adaptation
The development and persistence of these elongated canine teeth in Chinese water deer illustrate evolutionary adaptation, driven by sexual selection. In environments where antlers might be a hindrance, such as dense vegetation, tusks offer an alternative and effective tool for male-on-male competition. Evidence suggests that Chinese water deer evolved from ancestors that did possess antlers, but were subsequently lost. The tusks then became the primary means for males to compete for breeding rights and attract mates.
The size and prominence of a male’s tusks can signal his health and maturity, influencing female mate choice. This adaptation allows them to thrive in their ecological niche, where smaller, more agile weapons are advantageous. The presence of these tusks highlights an evolutionary path within the deer family, enabling successful competition and reproduction without the need for antlers.