Deer antlers are biological structures that undergo a remarkable annual transformation. Many people wonder about their growth, particularly if deer experience discomfort or itching as these structures develop. Understanding the biological mechanisms behind antler growth can clarify these curiosities.
The Annual Antler Cycle
Deer antlers are unique in the animal kingdom, as they are true bone structures that grow and are shed annually. This cyclical process begins in the spring when new antlers start to emerge from bony projections on the deer’s skull called pedicles. Antler growth is remarkably fast, with some species experiencing growth rates of up to an inch per day during peak periods.
Hormones play a significant role in regulating this rapid development. Increasing daylight in spring triggers a rise in testosterone and growth hormone, which are key to initiating and sustaining antler growth. The antlers continue to grow throughout the summer, reaching their full size by late summer or early fall. Once fully grown, a decrease in blood supply to the antlers occurs, and the bone hardens, preparing them for the breeding season.
Velvet’s Role and the Sensation of Antler Growth
During their growth phase, antlers are covered by a soft, fuzzy skin known as velvet. This velvet is highly vascularized, supplying the rapidly growing bone with essential nutrients and oxygen. The velvet is also richly innervated with sensory nerve fibers, primarily from the trigeminal nerve.
This extensive nerve and blood supply makes the growing antlers sensitive and vulnerable to injury. As the antlers near full development and begin to calcify, the blood flow to the velvet diminishes, causing it to dry and crack. This drying process of the velvet, combined with the hardening bone, likely causes irritation or discomfort, often described as an “itchy” feeling.
Deer Behavior During Antler Development
As the velvet dries and becomes irritating, deer exhibit distinct behaviors to remove it. Bucks commonly rub their antlers against trees, shrubs, and other objects in their environment. This rubbing behavior primarily serves to shed the velvet.
Beyond velvet removal, rubbing also serves other functions for deer. It helps to strengthen their neck muscles in preparation for the rut, where antlers are used for sparring and establishing dominance. Additionally, deer utilize scent glands on their foreheads to deposit their scent onto rubbed surfaces, marking their territory and communicating their presence.