How do antlers

Mule deer, named for their large ears, are found in North America west of the Mississippi River and especially in the Rocky Mountains. Mule deer use their antlers to compete with each other for mates and territory. A deer's developing antlers have blood vessels underneath a velvety skin, which can help regulate body temperature. We should also remember that antlers fill an ecological role, so their usefulness extends beyond the deer.

Once they are shed, they become an important source of calcium and other minerals to a variety of small animals, especially rodents like squirrels, mice, and porcupines! It is not unusual to find shed antlers with teeth marks on them. You can also speak with our Discovery Squad and Science Hub staff and volunteers to learn more during your next visit. Skip to main content. The Field Museum. Tickets Membership The Field Museum fuels a journey of discovery across time to enable solutions for a brighter future rich in nature and culture.

Caribou Caribou also known as reindeer use their antlers to scrape away snow and soil to find food, as well as to defend themselves. In addition to the direct effect of predation, the mere presence of predators increases energy demands as deer must be more vigilant and expend more energy to avoid them. You should also keep other disturbance like human intrusion to a minimum.

Last, but certainly not least, is minerals, and this is where things really get interesting. What we do know is that because they make up a significant proportion of the final product, calcium and phosphorous are key elements.

Other trace minerals like manganese, copper, zinc and selenium likely also play some role, though to what extent is unknown.

We also know that selenium is present in higher concentrations in velvet and the growing antler tips. This is why soil is so important, and why you should test your soil and follow the recommendations. Plants take up minerals and other nutrients from the soil. The richer the soil, the richer the plants. Deer then eat those plants and convert their nutrients into useable form for various bodily functions, not the least of which is growing a crown of antlers.

However, the path from soil to antler is indirect. The process of converting these elements into bone is called mineralization. And even when minerals are abundant in the environment, much of what goes into antlers is mobilized from other parts of the skeleton. During peak antler growth periods, bucks may experience a 20 percent decrease in mineral content in other bones. This, in part, explains why there is typically a big jump in antler growth between age three and four.

By age four a buck is mature. His skeleton has stopped growing and no longer requires as much mineral nutrients. Antlers are still a luxury, but any surplus minerals not needed for normal body function can now go directly to antler growth.

This is also why age is such an important factor in antler growth. Maximum antler size is usually achieved between age five and seven. After that a buck reaches senescence and a period of gradual deterioration. The process of mineralization occurs largely toward the end of the annual antler growth cycle. Photoperiodism - in this case shortening day length - again plays a role, stimulating the pituitary gland to increase secretions of testosterone.

This triggers the mineralization process as soft antler tissue is converted to bone when minerals are deposited within the matrix of cartilage and blood vessels. A once diffuse vascular system solidifies, cutting off the supply of blood and minerals. The antlers and their velvet covering literally die.

Velvet sloughs off completely within about 12 hours, leaving the dead bone of the completed rack behind. Exceptions do occur and are usually the result of injury, often to the testes, or sometimes the result of retarded testicular growth. This is also sometimes the case with deer erroneously labeled as antlered does. They may actually be bucks whose secondary sex characteristics penis and testes never fully formed. Antlers have many interesting characteristics but one of the most fascinating is that, like leaves on a hardwood tree, they are deciduous.

In an annual cycle they are grown, cast off then regrown again. Once the breeding season is over their purpose is served. In cold climates they act as radiators, drawing valuable heat energy from the body and retaining them only wastes valuable energy. Eons of natural selection have determined that it is more energy efficient to cast them off and grow a new pair than to carry them over the course of a lifetime, like horns.

Yet again, photoperiodism plays a role. Eventually, a specialized layer of cells called osteoclasts forms at the abcission line between the pedicle and antler base, ultimately degrading the point of attachment until the antlers simply fall off. They cycle is complete but will begin again as the sun slowly increases its duration in the sky.

Most folks know the three main factors in antler growth are age, nutrition and genetics. As managers we can really only influence two. By providing proper nutrition and letting bucks to reach maturity we allow them to reach their maximum genetic potential.

He discusses antler genesis and what we can do to help grow the healthiest deer possible. Listen below:. Break-Up Country. Elements Agua. Elements Terra. Shadow Grass Habitat. Explore All Patterns. Back About Our Story. In a matter of weeks, the cycle starts all over again.

Depending on the photoperiod, or amount of sunlight during the day that a male cervid is exposed to, they will either be growing or shedding their antlers. Generally, the more sunlight there is, the more the antlers will grow.

The change in light triggers the pineal gland to tell the pituitary gland to release more testosterone. With the boost in testosterone, deer antlers can grow up to two inches per week, and in some cases, bull moose can put on a pound of bone per day during the peak of their growth cycle.

Here is a general timeline of the antler growth cycle , although, depending on the area or species, the exact months may differ. It is slow to start, growing from the tip out.

June to July Mid Summer With the increase in sunlight, growth increases rapidly. September Late Summer As fall draws near and the days get shorter, growth slows. The antlers become mineralized, harden up, and blood eventually stops flowing to the velvet. The velvet dries, and afterward, it takes about 24 hours for a buck or bull to shed his velvet. October-December Fall to Winter The hardened antlers are now dead bone, and at this point bucks or bulls use them for the things that they do best during the rut: rubbing trees, fighting, showing off to females, and getting into all sorts of trouble.

January-March Late Winter to Early Spring Male cervids can only maintain a connection between the pedicle and the antler when testosterone levels are high, so as daylight hours dwindle, levels taper off, the connection weakens.

Eventually, the antlers are shed, and without them, the pedicles are open wounds. Scabs form, and in a matter of weeks, antler growth begins again. Two fast-growing bones on your head are going to cost something, and for deer, elk, and other cervids this cost is huge.

The skeletal sites are replenished later through dietary intake. In other words, to grow their antlers so fast, whitetails and other cervids need to borrow minerals like calcium and phosphorus from non-weight-bearing bones. Soils with poor mineral content, make it harder for recovery, and in a lot of cases where soil quality is low, supplemental feeds help to make mobilization a little more efficient. As stated above in the section outlining factors for growth, the only way to really dive into the role of genetics is to control the environment and nutrition of two or more genetically different deer.

MSU did just that in this study. Researchers took pregnant does from three distinct regions of Mississippi that represent different genetics, the Delta a lot of nutrients and genetically large deer , Thin Loess less agriculture and slightly smaller deer , and LCP genetically smaller deer with poor nutrition.

The plan was to feed the male fawns from the does the exact same high-nutrition diet and see how they grew in captivity. If the smaller deer remained small and the genetically bigger deer remained large, then it could be said that genetics, regardless of nutrition, can hold back the growth of body size and antler size. If the smaller deer grew as large as the others, then nutrition would surpass genetics as the most important factor for growth.