Author: Buck Manager

Age Deer by Teeth: Tooth Wear and Replacement

Aging Deer by Teeth

This page is intended to inform hunters and those managing deer how to age deer by looking inside their mouths, specifically by looking at their teeth. The tooth wear and replacement method is one of several techniques used for harvested aging white-tailed deer. This technique of aging deer by teeth has been used for half a century to age and manage deer on ranches across the US.

Although this method is far from perfect, it has been used in the successful management of deer herds since tooth wear is site-specific, which mostly depends on the types of soils as well as diet. Aging deer takes place by examining the wear and replacement of the premolars and the molars found on the top side of the lower jaw bone.

As a deer grows ages, its teeth wear down. As the enamel begins to wear away, and the exposes the dark dentine material and noticeable distinctions in tooth wear begin to occur between each age class. Deer are aged in year and half increments, such as 1 1/2, 2 1/2, 3 1/2 etc., since fawns are born from late May through July and are not harvested until the fall hunting season.

Using Jaw Bones to Age White-tailed Deer

Why Aging Deer is Important

Deer managers may be, and should be, interested in deer ages from a deer management standpoint. Age data provides information about deer herd characteristics, hunting or mortality pressure on a particular age class, and progress of the wildlife management program. Anyone interested in deer management should have an interest in knowing how to age deer.

Age data becomes a valuable piece of information when used with other data, such as antler characteristics, dressed body weights, or lactation in females. As a result of this date collection, deer herd trends can be monitored if enough data is collected over time. Often these trends can be related to a particular management style, climatic conditions, or any other factors affecting deer.

Field dressed body weights, age, and antler measurements should be collected every year and from every deer harvested to keep a close eye on impact of management activities.

How Aging Deer by Teeth Works?

Deer can be aged using the tooth wear and replacement technique when we have them in hand. This is easily accomplished once the deer has been harvested and one side of the lower jaw is either exposed or removed. If you recently tagged one, congratulations are in order!

Aging deer using the tooth wear and replacement method is not difficult, but it will require practice on your part. When aging a deer, it will help to cut the skin along the edge of the jaw t allow better inspection of the teeth.  Of course, if you are planning to mount the deer, you are not going to want to cut the jaw. Instead, open the mouth and use a flashlight to get a good look. Otherwise, you can ask the taxidermist to save the lower jaw for you after the skin is caped.

First, let’s talk a bit about tooth terminology. You first need to know what you’re looking at before you begin aging deer by teeth. The basic terms include cusp, back cusp, lingual crest, enamel, dentine, and infundibulum. A cusp is a point of projection on a tooth. The back cusp is the very last cusp on tooth 6 on the cheek side of the jaw.  Lingual crest in the tooth ridge adjacent to the tongue.

Deer teeth parts and terms

Enamel is the hard, white, outer coating of the tooth. Dentine is the soft, dark brown, inner core of a tooth. And lastly, infundibulum is the crescent shaped depression in the central crown of a tooth between the enamel ridge or crest.

It’s not critical that one actually memorize these terms, but you will definitely need to know what is being referred to when learning how to age deer from jaw bones. Knowing the specific terms for the the parts of teeth does help when discussing with another person, such as a hunting buddy or biologist.

Age of Deer: 6-7 months

Aging fawns is not difficult. They will be 6-7 months of age during the hunting season of the year they were born. The size of the animal alone is using a good indication of age, but for confirmation, inspection of the teeth atop the lower jaw will indicate age. Fawns have 5 or less teeth present and the third premolar (tooth 3) has 3 cusps. Tooth 6 has not yet erupted. In younger fawns, tooth 5 has not erupted and only 4 teeth will be visible.

Fawn jaw

Age of Deer: 1 1/2 Years

A deer that is at least 1 year of age (but not yet 2) is technically referred to as a yearling. Hunters commonly use the word “yearling” to refer to a fawn. They are technically, well, fawns. You should be aware of this improper use of the word.

Yearling deer are easy to age. Tooth 3 has 3 cusps. Tooth 6 has erupted and is slightly visible just above the gum line. Also, later in the hunting season you may see tooth 3 as a 2 cusps tooth, but it will just be erupting and will be short. After 1 1/2 years of age, tooth 3 will always have 2 cusps (and this quickly eliminates the animal from being a yearling or fawn).

1 1/2 (yearling) jaw

Age of Deer: 2 1/2 Years

On a deer of this age, the lingual crest on all molars are still sharp and pointed. Tooth 3 will now have 2 cusps and the back cusp of tooth 6 is sharp and pointed. The enamel is wider than the dentine in tooth 4, 5, and 6.

2 1/2 year old jaw

Age of Deer: 3 1/2 Years

On a  3 1/2 year old deer, the lingual crest on tooth 4 is blunt. The dentine will be as wide or wider than the enamel in tooth 4. The back cusp on tooth 6 is finally showing noticeable wear and is starting to form a concavity.

3 1/2 year old jaw

Age of Deer: 4 1/2 Years

The lingual crest on tooth 4 are almost rounded off and lingual crest on tooth 5 are blunt on a deer that is 4 1/2 years of age. The dentine in tooth 4 us twice as wide as the enamel. The dentine is tooth 5 is wider than the enamel. The back cusp on tooth 6 is worn so badly that it slopes downward towards the cheek.

4 1/2 year old deer jaw

Age of Deer: 5 1/2 Years

A deer that is at least 5 years of age is considered mature. On a deer of this age, the lingual crest is worn away on tooth 4 and rounded in tooth 5. The lingual crest in tooth 6 is blunt and dentine in tooth 6 is now wider than the enamel.

5 1/2 year old jaw

Age of Deer: 6 1/2 Years

Once a deer hits 6 years of age, tooth 4 is worn completely smooth — no enamel ridge should be visible in the center of tooth 4. A small enamel ridge will be present in the center of tooth 5 and tooth 6. Lingual crest on tooth 5 is almost worn away and rounded in tooth 6. A deer of this age is plenty mature.

6 1/2 year old jaw

Age of Deer: 7 1/2 Years

A deer that reaches 7 1/2 years of age is old. Tooth 4 and tooth 5 are worn smooth. There are no enamel ridges present in the center of these teeth. The lingual crest is gone from tooth 6. Infundibulum in tooth 6 is a narrow crescent shape.

7 1/2 year old deer jaw

Age of Deer: 8 1/2 Years

A deer of this age is not common on most properties. On a 8 1/2 year old deer, tooth 4, 5, and 6 are completely dished out and no enamel ridges are showing in the center of these teeth. If you look atop the jaw bone and see anything that looks like the photo below, rest assured your deer lived a long life and would soon begin to suffer from the inability masticate (chew), if not already.

8 1/2 year old deer jaw

Tips for Aging Deer by Teeth

The tooth wear and replacement method is the single best way to age harvested deer, but learning how to age deer by teeth is not a one-time event. After looking at the photos above, you probably realize there is some amount of discretion that needs to be used when looking at and interpreting tooth wear. This technique works from place to place but is best suited to comparisons from a particular site, where tooth wear/estimated deer age is compared within and between age classes.

Tooth replacement is straight forward, but that only gets a hunter to 2 1/2 years of age on deer. At that point, it becomes both art and science with regard to best-estimating the age of a harvested deer based solely on tooth wear. It is recommended that hunters maintain game cameras and photo logs of bucks on a property from year to year where deer management is to be practiced, then the physical characteristics of bucks on the hoof during the year of harvest can be combined with the estimated age based on teeth/tooth wear.

Camera photos help develop an “assumed deer age” based on successive years of photos. Once the deer is harvested, the teeth and physical (body) characteristics can be used to cross reference one another so that hunters on the property become calibrated to how a middle-aged or mature buck, for example, look in the field.

Aging Deer Teeth Using Jaw Bones

Lastly, to assist with aging deer by teeth, a simple jaw spreader can be made from rebar and welded into a similar shape as the above photo. This tool comes in handy after the deer has been dead for some time and rigor mortis has set in. Insert the jaw spreader into the deer’s mouth as shown. Make sure the spreader is pushed completely through the mouth and then rotate the jaw spreader downward to open the mouth. A deer’s teeth are now visible for inspection/interpretation and you can age deer by the replacement and wear of the teeth. Again, a flashlight will be helpful on those deer that will not be cut and are headed to the taxidermist.

Aging White-tailed Deer on the Hoof

Learning to estimate the age of a white-tailed deer on the hoof is an invaluable skill for any serious deer hunter or manager, especially as it pertains to buck harvest. Whether you want to estimate the age structure of the whitetail population found on a property or want to make specific determinations regarding the harvest of particular bucks, it takes time to get good at aging live deer. This article is designed to start you on the path to accurately aging deer on the hoof.

Aging deer on the hoof

Most hunters do not have access to free-ranging deer of known ages, so this makes the learning process more difficult, but not impossible. Just about everyone is using motion-triggered cameras nowadays and these game camera photos provide excellent opportunities to practice. Whether you use your trail cameras to conduct surveys to estimate your deer population or just to gather snapshots of bucks using the area, accurately estimating ages is paramount to assessing the progress of a management program.

Aging of Bucks is Important

Harvesting bucks at the optimal age is an important aspect of white-tailed deer management. Research and experience has revealed to biologists that whitetail bucks reach maximum antler growth between 5 and 7 years of age. There may be some hunters that insist on allowing bucks to get even older (and sometimes bigger), but annual mortality is always an issue with bucks, especially once their mature.

From my experience, free-ranging bucks that are 5 years old are old enough and will not increase substantially in antler size. Furthermore, research has found that a 4 year old (whitetail) buck’s antlers represent 90 percent of the buck’s potential for total antler growth. You will have some really good bucks even if the goal for the property/deer you manage is to get them to 4 1/2 years of age.

Aging Deer on Hoof

Besides, if you’re managing for 4 year old bucks then you will undoubtedly have some 5+ year old bucks on on your hunting grounds. Once a buck grows older he gets a bit smarter too, so he may become a live target at 4 years old but  drop off the radar come hunting season, only to re-emerge a year or two later, if you’re lucky.

Regardless of whether the goal is to harvest bucks that are at least 4, 5 or 6 years of age, it still takes hunters that are proficient at aging deer on the hoof to get there. Dead bucks don’t get any older.

Deer Management Means Learning to Age Whitetail

Whether you plan on harvesting bucks at 3 1/2 or 6 1/2 years of age you need to be able to estimate the age of deer on the hoof. The ability to rank a buck’s antler quality (compared to his peers) depends on property aging, too. There are three factors that influence antler size and development in whitetail bucks: age, genetics and nutrition.

The age of a buck is important for developing quality antlers and must be considered in combination with nutrition with some amount of genetic input. In fact, I find many properties are focusing way too much on genetics when efforts would better used enhancing deer habitat and simply allowing bucks to get older before they are shot.

The majority of hunters would be tickled pink to shoot a mature buck on quality habitat. It takes active management to provide good cover and food, as well as having a trigger finger that exhibits patience.

Improve Deer Aging Skills Through Backtesting

It’s not easy to age free-ranging deer when you’re starting out, but you can greatly improve “target recognition” through backtesting. This involves using game camera photos of bucks that you or others have harvested previously, off of your hunting grounds. Deer body sizes vary from place to place, so you want to learn using the deer that you will be hunting. It would not help much your management program if you could accurately age deer in Central Texas but were managing deer in Ohio. They look completely different.

Key points for aging deer on the hoof include:

  1. Shape of head – a mature buck’s appears short, deep
  2. Body size – younger bucks are thin, doe-like
  3. Neck – fills out deeper into shoulders as bucks age
  4. Depth of body – deeper body on older bucks
  5. Leg length – older bucks appear short-legged

Start a backtesting program on your hunting lands by maintaining game cameras prior to the hunting seasons. As bucks are harvested, age the bucks based on tooth wear and replacement. Over a few years you will start to get a good handle on what bucks of different ages look like. This is especially helpful when particular bucks can be tracked over several years.

Aging Bucks on the Hoof

Say a deer is shot at 5 1/2 years of age, well then if the buck is readily identifiable you can go back to your photo vault and see that same deer in prior years, say at 3 and 4 years of age and see how his physical and antler characteristics have changed.

Of course, I must mention that aging deer based on tooth wear is not an exact science either, as wear also varies from area to area based on soils. The teeth of deer that live in sandy soils wear down faster than the teeth of deer living on clay soils. The overall idea is to use tooth wear from harvested bucks and physical characteristics of those deer in photos to build the best photo library of “known-age” deer on your hunting grounds.

Aging Deer in the Field: It’s Not Perfect!

Aging deer on the hoof is an inexact science, but it’s all that we’ve got. Aging deer accurately beyond 2 1/2 years of age based on tooth wear (with the jawbone in hand) can be tricky enough for those just starting out, but estimating the ages of live deer in the field can be downright difficult.

My advice is to be patient and get photos of the bucks in your area prior to the hunting season. Start by sorting bucks captured on camera into groups such as young (1-2), middle-aged (3-4) and mature (5+ years old) and then see how those estimates play out come hunting season, once those deer are tagged.

As you will see, aging deer is not always clear-cut. Whether you are exactly right is not as important for your deer management program as whether or not you, or the other hunters where you hunt, can differentiate between older deer and high quality younger bucks with a lot of potential. Mistakes will always be made, so don’t waste them, learn from them.

Whitetail Deer Management – Proper Livestock Grazing

Wildlife habitat can be greatly enhanced through proper grazing management. Of course, deferred-rotational grazing of livestock (we are talking cattle here) is the best grazing system for wildlife, but some factors must be considered. Since rotational grazing requires mutliple pastures, livestock confined to individual pastures in a deferred-rotation grazing system, each pasture needs to have at least one source of water available when livestock are in that pasture.

Creeks may provide adequate water during most of the year, but water from seasonal streams may become limited or inaccessible during extended dry periods. Also, concentrated livestock activity around creek waterholes can cause excessive damage to the plants and soils in the area. Earthen stock tanks and/or water piped to troughs from a well may provide better, more reliable, sources of water. One water source can serve several pastures if properly located.

For example, one water trough could serve two pastures if straddled by a cross-fence, or a trough in a separately fenced “waterlot” constructed at the juncture of several cross-fences could serve numerous pastures. Also, permanently or seasonally protect the vegetation and soils in riparian areas (low areas on either side of stream courses) from damage such as can be caused by excessive, long-term livestock trampling.

Riparian area protection and enhancement can include providing livestock with alternate watering sites, deferring livestock grazing in pastures with riparian areas during critical periods of the year, total exclusion of livestock from pastures with riparian areas, and separately fencing riparian areas to exclude livestock or provide short duration grazing.

A deferred-rotation grazing system will fail to produce the desired results of maintaining a healthy and diverse plant community if the range is overstocked with animals, both domestic and wild. The appropriate livestock stocking rate for a specific ranch is dependent on that ranch’s herbaceous plant productivity and past grazing history. The stocking rate can vary from year to year, and seasonally within a year, depending on environmental factors. The impact of grazing animals should be closely monitored and the number of livestock on a ranch may need to be frequently adjusted to account for the variations in a ranch’s grazing capacity.

A good rule-of-thumb livestock stocking rate for native rangelands in much of east-central and north-central Texas is 1 animal unit (a.u.) per 15-20 acres. Recommended stocking rates decrease in a westward progression across the regions in association with decreases in the average annual rainfall. Stocking rates in central portions of Texas is 1 animal unit for about 25-35 acres, while it is 1 animal unit to 40-50 acres is more realistic for the further west.

The combined total of all animals on the range, including all classes of livestock as well as deer, must be considered when determining stocking rates. Weaned calves up to yearlings are classified as 0.6 animal units, steers and heifers up to 2 years old are considered 1 animal unit, mature cows are 1 animal unit, and bulls over 2 years of age are classified as 1.3 animal units.

With regards to deer management, sheep and goat operations are not recommended. It is commonplace for many “ranchers” to carry more livestock than the range can actually support. This is evident in herds of cows when individual animals look to be in below average condition. This can also be seen on rangelands that are comprised mostly of “weeds.” The reason over grazed pastures soon become fields of weeds is because over grazing occurs at the individual plant level, not at the pasture level. This may sound confusing, but hang in there.

Grasses are adapted for grazing pressure, but they are not foolproof. In the past, grasses did not adapt under continuous grazing pressure. Buffalo were the primary grazers over much of the United States and they migrated with weather patterns and seasons. As a result, a grass plant would therefore be grazed upon and then moving herds would move on to to fresh grass. Now, put a fence around an area of rangeland, add cows, and you have a contiuous grazing scheme. Bad move for grass, bad move for wildlife.

After a grass plant is grazed, much if not all of its leaves are removed, and therefore, the energy converting mojo of the plant is removed. Thus, the plant relies on energy reserves stored in the roots to refoliate and keep growing. No problem…unless your pasture is overstocked. With continuous grazing pressure, individual grass plants are repetitively grazed, never refoliate, and eventually energy reserves in the plant run out. The end result is a dead plant. This can happen over years of weakening the plant or over a much shorter time, depending upon the stocking rate.

Now, since we all know that cows prefer grass over weeds, the pasture soon becomes a field of weeds as individual grass plants die out and weeds benefit from the lack of competition. All this from continual grazing. By cross-fencing your ranch into mutliple pastures, you can rotate cattle through many pastures and give plants time to recover and regenerate through deferral periods.

Although deer do not consume very much grass (less than 9% of diet and only on young, new growth), they do require it for fawning cover and tall grass can also provide bedding and screening cover. Grazing your ranch is not a bad idea, but make sure you do it properly and it can be a great benefit to your overall deer management and cattle ranching program.

Deer With Seven Legs – Still Not Enough to Get Away

FOND DU LAC, Wis. – Rick Lisko hunts deer with a bow but got his most unusual one driving his truck down his mile-long driveway. The young buck had nub antlers — and seven legs. Lisko said it also had both male and female reproductive organs. “It was definitely a freak of nature,” Lisko said. “I guess it’s a real rarity.”

He said he slowed down as the buck and two does ran across the driveway Nov. 22, but the buck ran under the truck and got hit. When he looked at the animal, he noticed three- to four-inch appendages growing from the rear legs. Later, he found a smaller appendage growing from one of the front legs. “It’s a pretty weird deer,” he said, describing the extra legs as resembling “crab pinchers.”

“It kind of gives you the creeps when you look at it,” he said, but he thought he saw the appendages moving, as if they were functional, before the deer was hit.

Warden Doug Bilgo of the state Department of Natural Resources came to Lisko’s property near Mud Lake in the town of Osceola to tag the deer. “I have never seen anything like that in all the years that I’ve been working as a game warden and being a hunter myself,” Bilgo said. “It wasn’t anything grotesque or ugly or anything. It was just unusual that it would have those little appendages growing out like that.”

Bilgo took photos and sent information on the animal to DNR wildlife managers. John Hoffman of Eden Meat Market skinned the deer for Lisko, who wasn’t going to waste the venison from the animal.

“And by the way, I did eat it,” Lisko said. “It was tasty.”

Habitat Management – More on Grazing

A ranch must be divided into at least two pastures before even the least complex two pasture/one herd deferred-rotation grazing system can be implemented.   If not cross-fenced, the land manager would need to have access to other areas where livestock could be moved to during the prescribed rest periods.  Electric fencing is a lower cost and less labor-intensive alternative to barbed wire for dividing a ranch into multiple pastures. Continue reading “Habitat Management – More on Grazing”