Antlers are remarkable structures of bone that grow, shed, and regrow each year in members of the genus Cervus (true deer), which are part of the family Cervidae. Unlike horns, which are permanent, antlers are shed annually and serve crucial roles in reproduction and social signaling.
- Antlers are made of bone and grow from pedicles on the male deer’s skull.
- Growth occurs annually and is one of the fastest types of bone development in vertebrates.
- Antlers function primarily as weapons and displays during the breeding (rut) season.
- After the rut, antlers are shed and later regrown, a process tied to hormonal cycles.
Antlers are primarily made of bone.
*Cervus* belongs to the family *Cervidae*.
Antlers are used mainly for reproduction and social signaling.
Antlers are typically shed after the rut season.
Structure of Antlers
Antlers are solid, branching structures made of ossified bone that emerge from skull regions called pedicles. During their initial growth phase, antlers are covered in a vascularized skin known as velvet, which supplies nutrients and oxygen. Once fully grown, the velvet is shed, leaving behind mature, mineralized bone.
- Antlers are composed of bone, unlike horns which are keratin-based.
- Growth starts from pedicles—unique bony projections on the skull.
- Branching patterns increase with age and species.
- Velvet provides essential blood flow during early development, then is shed.
Antlers grow from pedicles on the skull.
Velvet, a nutrient-rich skin, covers growing antlers.
The velvet is shed to reveal mature antlers.
Antler Growth Cycle
Antlers grow annually, driven by changes in sex hormones (primarily testosterone). In spring and summer, rising hormone levels stimulate rapid antler growth beneath velvet. By autumn, growth ceases, velvet is shed, and antlers harden for the mating season. After the rut, declining hormones cause antler detachment, and the cycle repeats.
- Growth starts in spring with rising testosterone.
- Antlers fully develop before the breeding season (fall).
- Post-rut, falling testosterone causes antler shedding.
- New antlers begin growing almost immediately after shedding.
Testosterone drives the antler cycle.
Antlers grow in spring/summer, harden in fall, and are shed in winter.
Antler shedding is triggered by decreasing testosterone levels.
Biological Significance
Antlers primarily function in reproductive success (sexual selection). Males use them to fight (intrasexual competition) and to display dominance (intersexual selection), attracting females (does). The size and complexity of antlers are indicators of genetic fitness and health.
- Antlers are weapons for male-male competition during the rut.
- They serve as visual signals to attract females.
- Larger antlers usually indicate good health and superior genetics.
- Only males (and some female species like caribou) grow antlers, linking them to reproduction.
Antlers increase reproductive success and social dominance.
Females perceive large antlers as a sign of fitness.
Antlers contribute through combative displays and visual signals.
Antlers of the genus Cervus are dynamic, bone-based structures that reflect a male's reproductive status and fitness, with a unique annual cycle of growth and shedding tied to hormonal changes.
- Antlers grow from pedicles, in a rapidly ossifying process covered initially by velvet.
- They are central to mating strategies, providing both weapons and signals.
- The antler cycle is hormonally controlled, ensuring renewal every year.