Begin Main Content Area

Ask The Deer Biologist A Question


Go Ahead, Ask the Deer Biologist!

The world of white-tailed deer and the science used to manage them fuel countless questions from hunters and other Pennsylvanians who care about whitetails and natural resources. Interests and topics vary. But most people are just looking for answers to help them better understand what is happening in the woods or in the Game Commission's deer program.

If you have a burning question, consider submitting it to our biologists in the Deer Section. If your question is selected, a detailed answer will only be a click away. Every two weeks biologists will select and respond to several submitted questions. These questions and answers will then be posted on this website to help everyone enhance their knowledge of deer and deer management. If you'd like to submit a question, click on the "Submit a Question" link below. If you'd prefer to review previously-answered questions, click on "Questions and Answers."

Submit A Question

Questions & Answers

What colors of light can whitetails see? If I walk into the woods with a flash light, can deer see it? I was told to use a red or green lens on my flashlight.

Day or night, a deer’s visual acuity is excellent. For low light situations, a deer’s eye is equipped with a membrane, the tapetum lucidum, which reflects light back through the receptor layer of the retina. By passing light through the receptor layer twice, a deer’s vision in dim light improves. Deer can also see well in bright light. A ring of pigment surrounding the cornea likely acts as an antiglare mechanism.

Deer have a much higher density of rods in the retina than cones. Rods are photoreceptors and therefore are more sensitive to light but are not sensitive to color. Cones provide color sensitivity and high resolution vision. Rods are more than one thousand times as sensitive as cones to light. Rod sensitivity is shifted toward shorter wavelengths (green) of the color spectrum peaking sharply in the blue and respond very little to red. Rods are also better motion sensors than cones.

Even though deer have less than half the number of cones in the eye as people, deer can still distinguish among different colors. During low-light conditions, deer are likely more sensitive to the blue to blue-green portion of the spectrum (due to the high rod density). Studies indicate that deer are less sensitive to light of long wavelengths (orange and red) and rely upon their perception of only 2 colors – yellow and blue.

So to answer your question, a deer can see your flashlight at night regardless of the color. They may not be able to distinguish the color of the light but this will not reduce their ability to detect it as the many rods in the eye are designed as photoreceptors.

When do bucks begin to rub trees and leave scrapes?

A buck’s antlers are hard and velvet is shed by September. This is when rubbing activity begins. These early signposts are usually made by more mature bucks. Yearlings make about half as many rubs as mature bucks. Age also plays a factor in tree size selection. Older bucks rub much larger trees. Yearlings typically rub saplings no more than 2 to 3 inches in diameter. Compare this to a mature buck who may rub pole trees 6 inches or larger.

Scraping has been observed from July through March but is typically done when antlers are hard. This complex signpost is used more intensely just before the peak of the rut. Most adult does in Pennsylvania are bred in November with median conception dates between November 11-17. So expect most scrapes to be made prior to this in the fall.

Another article that may be of interest to you is Bubba was here – from Life & Times of the Whitetail series and can also be found on our website.

Is it true that the PGC is going to do away with the Citizens Advisory Committees with regard to whitetail deer? If so, why?

Yes, it is true the PGC is discontinuing Citizen Advisory Committees (CACs) for deer management.

The PGC began using CACs in 2006 with a pilot in Wildlife Management Unit (WMU) 4B. Since then a CAC has been completed in every WMU.

In 2010, a legislatively-sponsored, independent audit of the deer management program was completed by the Wildlife Management Institute (WMI). One of the recommendations by WMI was to transition from CACs to a more representative citizen survey. From the WMI report (PDF), “the CAC process, while grounded in social science, may not be an efficient or fully objective method to assess citizen desires in each of the 22 WMUs…”.

CACs served their role, but in practice, there were many challenges. It was difficult to get people to serve on the CAC. CACs were often lacking representation for key stakeholder groups. And while the CAC process was beneficial for those involved, the scope was limited and likely did not represent the entire WMU.

Recommendations of the CACs did not influence the decision to discontinue them. In fact, Game Commission staff made recommendations to implement the recommendations of 16 of the 20 CACs that reached a consensus recommendation. Two WMUs did not reach a consensus recommendation.

Citizen input will always be a part of the deer management program. The PGC is moving to a citizen survey to ensure the interests of all are represented as the future success of deer management depends on greater understanding of stakeholder values and attitudes.

We live within a Golf Course and I have considered putting out food in winter for deer. What would you suggest?

Feeding wildlife is generally a bad idea. Research has shown that artificial feeding alters natural foraging behavior resulting in changes in deer movement and distribution patterns. It is also well documented that supplying food to wildlife, including deer, carries with it a host of negative effects.

There is an increased risk of disease transmission between animals associated with feeding. Feeding sites may harbor and concentrate disease agents deposited by infected animals creating a reservoir of contaminated feed or infectious excreta. Deer cannot avoid fecal consumption at feed sites. Some diseases and parasites spread through ingestion of contaminated excreta material include bovine tuberculosis, CWD, salmonellosis, toxoplasmosis, large lungworm, and larval tapeworms.

While contagious and infectious diseases are a major concern, lactic acidosis or grain overload is associated with feeding as well. Lactic acidosis is the fatal disruption of the body’s acid-base balance in the rumen and has been documented in the Pennsylvania.

Another issue of concern regarding deer health and feeding is emerging new syndromes being documented. Mild to marked hair loss syndrome and soft tissue inflammation of the muzzle are two newly recognized conditions associated with feeding. The cause of the hair loss syndrome is unknown but many parasitic, infectious, toxic causes have been ruled out. Soft tissue inflammation of the muzzle is a kind of bacterial infection (Dermatopylosis congolensis) and has not previously been seen in white-tailed deer. There is also increased fighting and injury at feed sites.

While there are documented health risks to deer that are provided feed, there are risks for other nontarget species as well. Feeding deer may be the objective but this does not stop other species from using the available resource for their benefit as well. Feed used to attract deer will likely draw turkeys, squirrels, raccoons, opossums, rodents, skunks, and foxes, directly or indirectly. And just as feed sites increase risk of disease exposure and transmission in deer, these sites will do the same for these nontarget species. Many of these species are known carriers of transmissible disease. Some of which are high risk like rabies. Other diseases include canine distemper, parvovirus, leptospirosis, baylisascaris and ascarid roundworms, avian pox, and trichomoniasis.

As a result of these documented risks, the Game Commission cannot recommend any feeding of white-tailed deer. We have also created a brochure with some of this information, Please Don’t Feed the Deer (PDF). Other articles that may be of interest to you I’ll just have a salad and Did someone say FREE food? – both from Life & Times of the Whitetail series – can also be found on our website. I encourage you to download and review them all

If you want to help the deer in your area, improve the habitat on your property. Information can be found on the Habitat Management page. There is also the Private Landowner Assistance Program, which helps landowners improve their property for wildlife.

I live near the city of McKeesport and there is a buck with 4-points on one side and a drop tine of the other. My question is will that buck, if he makes it through the season, grow a drop tine the following year?

The answer is maybe. Antlers are a complex business. And the more complicated something is, the easier it is for things to go wrong. Most of the time the cause of antler abnormalities, in this case drop tines, is unknown but there are 3 likely suspects:

  • Defects are coded in the genes themselves
  • Defects are a result of a physiological problem (bodily injury, disease, parasitism, etc)
  • Defects are due to a direct injury to the pedicle or the growing antler

Rack shape, tine length and configuration, and other individually specific features are hereditary or coded in genes. Antler abnormalities of genetic origin are expected to occur in both antlers as well. There is no wiggle room in genetic code, so only important antler traits are strictly coded in genes.

Antler abnormalities caused by defects not relating to genes are far more common. The results are endless. Like snowflakes, no 2 are alike. Generalities can be made such as “contralateral effects”, where injury to one side of the body causes antler deformity on the opposite side. The reasons for this are unknown. And exactly how the antler will be altered from its original size or shape is anyone’s guess.

So getting back to the question, will this buck have a drop tine next year? If it is a true genetic defect, he will grow the drop tine again with his next set of antlers. If it is a result of something else, his next rack may be normally shaped with no sign of a drop tine.

I hunt in WMU 4B. I understand some antlerless deer have been tagged with reward tags. What do these tags look like? How many deer have been tagged? Have any been harvested this season?

In April 2008, Pennsylvania’s Board of Game Commissioners authorized a change in the firearms season in 4 Wildlife Management Units (WMUs) for the 2008-09 hunting seasons. In WMUs 2D, 2G, 3C, and 4B, the firearms season changed from a 12-day antlered and antlerless season to a 5-day antlered only season followed by a 7-day antlered and antlerless concurrent firearms season.

This season change prompted a research study in these units which was designed to answer the following questions: 1) How will antlerless harvest change? 3) Will hunter satisfaction increase? 2) Will hunters see more deer? 4) Will age structure of the antlered harvest change?

To date, hundreds of deer have been captured in WMUs 2D, 2G, 3C, and 4B. Some received radio collars while the majority received reward ear tags. Ear tags are button-like tags designed to blend in with the deer’s ear and are stamped with the necessary contact information. To learn more about the study including the number of deer tagged in each study area and mortality, go to the latest Wildlife Management Annual Report 21015.

How long does it take for a deer’s antlers to harden? What month of the summer does it happen?

Antler growth is a complex process drive by hormones and photoperiod (day length). Antler tissue is the fastest growing tissue known to man having the capacity to grow an inch or more per day. Annually, antler growth begins when the days are lengthening, between the spring equinox and the summer solstice (mid-March through mid-April). Antlers grow from the tip and are full of thousands of blood vessels.

As the summer progresses and day length begins to decrease, testosterone production increases. This triggers mineralization or hardening of the antlers. The soft tissue is transformed directly into bone by the depositing of minerals within the cartilage matrix through the extensive capillary network-hardening the antlers from the base to the tip. Antler-hardening takes about a month starting in mid-July and ending in mid-August. After which time, the velvet dries up and is rubbed off.

After the breeding season, testosterone levels drop off and antlers are shed in late winter/early spring. And the process starts all over again.

Do you think hunters buy hunting licenses to see deer, or to watch tree’s grow? I do not need a license to watch trees grow. We are losing hunters every day due to the low deer numbers in Wildlife Management Unit 4A and 4D.

The argument that hunter numbers are declining because of reduced deer populations is not true. Hunter numbers have declined since 1983 at a consistent rate regardless of fluctuations in deer abundance. Recently an article addressing this was published in Game News. Fewer Deer & Fewer Hunters: Are They Related looks at the relationship between deer numbers and license sales.

With regard to deer and trees, the PGC’s deer management program includes a goal to manage deer for healthy and sustainable forest habitat for a number of reasons. First, this goal was unanimously selected by a group of statewide stakeholders – including the PA Federation of Sportsmen Clubs, Unified Sportsmen of Pennsylvania, PA Deer Association, Quality Deer Management Association, United Bowhunters of Pennsylvania, and National Wild Turkey Federation. Second, the PGC’s constitutional and legal mandates require us to manage deer in the context of what is best for deer, wildlife, and habitat for now and into the future. Forests are a critical habitat for most wildlife in Pennsylvania. Third, it is well documented that deer can negatively impact forest regeneration when not managed properly. Finally, deer rely on seedlings and saplings (i.e., regeneration) for browse. Therefore, our goal of considering forest sustainability and regeneration as part of the deer management program is appropriate and responsible.

Further information on the PGC’s deer management program and the role of forests in deer management can also be found in What is a healthy forest?

What percentage of the fawns are bred during their first rut, and if they are bred, how many are producing multiple offspring?

The percentage of female fawns that breed during their first fall varies across the state from a high of 45% in WMU 5D to a low of 6% in WMUs 2G and 3D. Whether a female fawn comes into estrous when she is 6-8 months old is directly connected to her weight. Fawns reach puberty at 80 to 90 pounds. If this critical weight is attained, female fawns will come into estrous their first fall. Of the fawns that breed in Pennsylvania, most (>80%) have single fawns. Less than 20% have twins during their first pregnancy.

At what age can a fawn live on its own? If an archer harvests a doe, and the doe is with a fawn, what are the chances of the fawn living on its own? Would another doe take it under its wing, ever?

Fawns are functionally weaned by the time they are 10 weeks old. They will still nurse if allowed up until they are 5 or 6 months old. However, this is not necessary for their survival. After 10 weeks of age, fawns are perfectly capable of obtaining food on their own by grazing and browsing. Deer do learn feeding behavior so the longer a doe and fawn are together, the more the fawn learns. By the time archery season rolls around, fawns are self sufficient and they remain with their mother for purely social reasons. Orphaned fawns are rarely adopted but there is no need of this in the fall anyway.

Why do bucks group together just prior to the rut? On several occasions over the years I have seen as many as four bucks together on a daily basis during August on my property.

Bucks usually associate with unrelated individuals in bachelor groups during the spring and summer. During this time, they recover for the previous season’s rut and the hardships of winter while growing a new set of antlers. These are loose associations and the composition of the group may shift as the summer progresses with different age class animals shifting in and out. While this is a quiet and “relaxing” time of year for bucks (testosterone production is very low), they spend this idle time learning about each other perhaps gathering information that may be useful to them in the coming months.

What is the purpose of the tongue flicking when a buck is chasing a doe during the rut?

This behavior is likely related to vomolfaction, a chemical sense involving the vomeronasal organ. Unlike olfactory receptors in the nose, which detect molecules in vapor, the receptors in the vomeronasal organ are sensitive to non-volatile compounds, those that cannot be inhaled. Not being airborne, these compounds must come in direct contact with the receptors. Tongue movements are important in capturing these compounds (say from urine or in close proximity to a doe) mechanically moving them to a pair of pores in the roof of the mouth which leads to the vomeronasal organ. This sense plays an important role in determining if a doe is approaching estrus.

Approximately how many piebald deer are in the state of Pennsylvania?

With the millions of genetic combinations that occur when deer breed, piebald deer are rare but widely documented throughout the range of the whitetail. Usually, they are reported at rates under 1% in the population. Limited observations indicate normal and piebald deer crosses produce both normal and piebald offspring. This rate can increase if piebald deer are protected making the genes for this condition more common in the population.

I wanted to know about deer warts. Are they contagious to humans or animals? How does a deer get them?

Cutaneous fibromas are commonly known as deer warts. Fibromas are caused by a virus. The virus is an obligate inhabitant of a deer’s skin and poses no known threat to people or domestic animals. Transmission is thought to occur through biting insects and possibly by direct contact with various contaminated materials that might scratch the skin. While unsightly, fibromas are merely surface blemishes and only cause concern to a deer when they interfere with sight, respiration, eating or walking. The only concern for hunters would be fibroma with a secondary bacterial infection rendering a deer unfit for consumption. Mississippi Department of Wildlife, Fisheries, and Parks has a detailed narrative on their website, Cutaneous Fibromas In Deer: A Closer Look, (Warts, & All).

How much of an impact does coyote predation have on our deer numbers in the big woods/farming areas of north central Pa.?

Based on research conducted in Pennsylvania, the impact of coyotes and other predators on deer varies by area and age of the deer. In forested areas of north central Pennsylvania, predators cause the majority of deaths of newborn fawns. Predator kills were evenly divided among coyotes, bears, and other predators. However, in agricultural areas of central Pennsylvania, natural causes – such as starvation, failure to nurse, infections, parasites – caused the most deaths of newborn fawns. Despite predators, 57 percent of fawns born in north central Pennsylvania and 72 percent of fawns born in central Pennsylvania survived through the summer.

Although predators kill a percentage of fawns, we have not observed many predator kills on older deer. We have captured and tracked more than 1,000 deer older than 7 months of age. Of these deer, we have confirmed 5 predator kills to date. For our tagged deer, more than 70 percent of them will die due to hunting whereas predators account for less than 1 percent.

I always thought deer poop was deer poop. In the last month I have had two different people ask me if it was true that female deer poop was shaped differently than male deer poop. Now I would think deer poop would depend on what they had to eat. Am I right?

What comes out of a deer is simply a function of what goes in. Deer pellet shape is not determined by sex of the animal, but by their diet. Deer mostly on browse or other fibrous material will produce pellet piles consisting of loose, individual pellets. When deer are eating less browse and more green and succulent vegetation, the individual pellets may form into a single clump.

How long do deer usually live in the wild and how long do they live in captivity?

Deer can be very long lived. In the wild, there have been documented cases of deer as old as 10.5 years (PA), 18.5 years (NJ), and 20 years (NY). But with hunting pressure and other mortality factors (like disease and injury), the average age in the wild is usually 2 to 3 years. In captivity, deer have lived up to 25 years.

I hunt in the Wildlife Management Units 2F and 2D. As management goals are met for deer, when can you foresee a cutback in doe tags and an increase in the deer population?

In order to recommend a deer population increase in any WMU, 3 things need to occur. The first two things, deer AND forest habitat health need to be at target levels (see Deer Management Plan goals and measures). The third piece, people have to want more deer. The goals of deer and forest habitat health are evaluated by data collected on an annual basis. These evaluations are presented every year to the Board of Commissioners at the April commission meeting and subsequently posted on the PGC website for each WMU (Annual WMU Population Assessments & Antlerless Allocations). As for the views of people with regard to deer populations, the Game Comission uses a citizen survey. The last survey was conducted in 2011 and can be found here.

Can whitetail deer breed with mule deer and vice versa?

Yes, interbreeding may occur in areas where their ranges overlap and this hybridization has occurred in captivity. However, the offspring are at a severe disadvantage in terms of predator evasion. The mule deer’s strategy for escaping predators is the stott, a specialized form of locomotion slightly slower than a gallop. Unless the deer is 100% mule deer, it cannot stott. The whitetail aims for speed in predator evasion. A hybrid has difficulty jumping obstacles and does not run from or attack a predator. The instinct of how to evade danger successfully is a genetic trait, not a learned behavior. In one experiment, when deer were confronted with a large leashed dog, whitetails fled; mule deer assembled and attacked stotting around the would-be predator; hybrids approached the dog at a walk, stopped, looked, turned, looked over their shoulders and generally acted confused. This type of predator evasion is not very successful in the wild.

I'm curious about the behavior of deer in winter known as yarding or herding. It seems counter productive that deer would herd at a time of year when food sources are least available. Wouldn't population dispersal be more beneficial to take advantage of a wider geographic area of food sources?

The primary reason for yarding (congregations of deer during the winter in sheltered areas) is protection from the cold. Seeking shelter minimizes radiant and convective heat loss thus conserving energy when frigid temperatures and blustery winter winds stress a deer’s metabolism. Research has shown that shelter is so important during extreme cold weather that deer will stay in a yard even if food supply is low. Yarding behavior is common in states with extremely cold temperatures like Michigan and Minnesota. In Pennsylvania, deer do not really yard but do have a tendency to concentrate in hollows and hillsides with mountain laurel or rhododendron cover. Prolonged severe winter weather may force deer to yard up and consume all available food. If severe weather persists, only the largest deer are able to obtain any browse and younger animals may succumb to the harsh realities of nature.

My cousin shot a doe yesterday (January 21) at a controlled hunt area and when he field dressed her, fawn embryos were present. How could this happen?

Ninety percent of adult does in Pennsylvania are bred between October 16 and December 16 with the peak of breeding occurring in mid-November. This doe had likely been pregnant for over 2 months and possibly over 3. Total gestation for white-tail deer is about 200 days. She was probably at least 1/3 of the way through the gestation period. Embryos are well developed by this stage with muzzle, hooves, and sex all discernable.

I have been reading articles about how young male deer will disperse one to three miles in the spring from the area where they were born. Does this still happen if the doe (mother) has been killed?

Based on research conducted in Pennsylvania and elsewhere, there is some evidence that removing the mother can reduce dispersal by young males during the spring fawning season. However, during the fall, when young males also disperse, social pressures from other males appear to be the most important factor. The end result is that between 6 months and 16-18 months of age, about 70% of young bucks will disperse an average of 3 to 6 miles regardless of whether their mother was killed.

How do you tell the age of a deer?

To accurately age a white-tailed deer with certainty, the best method is to pull the lower incisor, root attached, and send it to a laboratory for cross sectioning. Many mammals, including deer, can be aged by staining these teeth and counting the rings that appear, just like on a tree. This process of measuring a deer’s age takes time and money; therefore, in most cases, estimating a deer’s age is enough.

The age of white-tailed deer can be estimated by tooth wear and replacement patterns. Although antler size does increase with age, interactions between genetics and nutrition cause much variability in antler growth. For example, a young buck with a high quality diet may have a larger rack than an older buck with a poor diet. However, like children, deer replace their teeth in a systematic fashion.

Up until about 10 months old, a deer will have up to five teeth, premolars and molars, on each side of its lower jaw. Premolars are replaced as a deer reaches adulthood. Molars are permanent teeth they will have their whole lives. Jaws that have five or fewer teeth (3 premolars and 2 molars) are considered fawns.

Just before their first birthday, their 3rd and final molar will develop and begin to emerge bringing the count up to 6 teeth per side. At the same time, the premolars are also being replaced. During this period of emerging premolars and molars and tooth loss, a deer is considered a yearling as these events coincide with their first birthday and the several months that follow.

After these noteworthy dental events, determining the age of a deer relies on tooth wear. As a deer gets older, their teeth wear down from grinding their food. These wear patterns can be predictable to a point. There are many factors that influence the individual tooth wear patterns of deer: type of food eaten, soil types, injury, individual chewing patterns, etc. Once all teeth are replaced, it is difficult to determine the age of a deer with certainty based on wear patterns alone.

This is why the Game Commission ages deer into only 3 categories when collecting harvest data from processors every fall. Trained Game Commission deer agers can reliably age deer to 6 months (fawns), 18 months (yearlings), and 30+ months (2.5 years or older). Those with much experience may venture a guess beyond 2.5 years old but this is more of an art then a science.

I hunt in Wayne County, both WMU's 3C and 3D and this year I noticed several bucks in 3C that already lost half of their antlers. When I shot my buck during the first week of rifle season, my buck’s antler fell off in my hand. Why are bucks in 3C losing their antlers earlier than other deer in parts of the state? Is it nutrition?

Natural variation and general health (which relates to nutrition) of a buck contribute to the timing of antler drop which occurs any time from December through March. Each year during the firearms season, PGC deer aging personnel in all areas of the state see bucks that have lost one or both of their antlers. In 2008, Pennsylvania had a poor acorn crop and a late gun season (due to Thanksgiving falling so late in November). These 2 factors may have contributed to more hunters noting antler drop during the gun season. Had the 2-week gun season started a week earlier, buck antlers would likely have been securely fastened to their heads.

I have a question regarding the dispersal habits of yearling bucks. While hunting on my property during this past archery season, I past up several shot opportunities on two yearling bucks that I saw several times. Assuming these bucks survive, what is the likelihood that I will see these two deer during next year's season?

Dispersal, or movement away from the area where the buck was born, is common in Pennsylvania. Results from our ongoing buck study indicate between 45 and 75 percent of all yearling bucks will disperse. Although some dispersal occurs in the spring, when bucks are 11 to 12 months old, most dispersal occurs in the fall, during October and November, prior to the peak of the breeding season, when the bucks are 16 to 17 months old. So if yearling bucks are seen after the breeding season (mid-November), it is likely they will be there next year.

I have often heard that an injured buck will grow a "non-typical rack". I was once told that an injury on the left side of a buck will cause an irregular rack on the right side and an injury on the right side of a buck will cause an irregular rack on the left side. Is this statement true? And if it is true what causes this to occur?

Injuries can affect antler development. The most obvious is a pedicle (base) injury that can cause the entire antler to be “deformed” while the other antler is normally shaped. However, bodily injuries can also cause antler deformities. Hind limb injuries typically affect antler development on the opposite side of the body. This is because nerve pathways cross in the brain. Information carried on the spinal cord enters the part of the brain known as the medulla oblongata. From here the information crosses to the sensory cortex for processing. So information transmitted from the right hind limb ultimately ends up on the left side of the brain.

Research suggests that antler growth is influenced by two independent growth centers in the brain. Injury to a limb may stimulate the antler growth center which causes abnormal antler growth. Hind limbs have an increased number of nerve fibers so trauma to one of these is more likely to impact antler growth centers in the brain than trauma to the front legs. And while it has been suggested that front leg injuries affect antler growth on the same side as the injury, this has not been proven.

Even after an injury has healed, the brain may retain a “phantom memory” of the injury making it possible for deformed antler growth for multiple years.

My understanding is that antler restrictions have a couple benefits. One, it increases the number of older bucks in the population, which, as I understand it, has certain biological benefits. Two, it can refocus hunting pressure on antlerless deer (along with the number of doe permits). One concern I have is that the number of button bucks killed in a given year has increases since antler restrictions were implemented. Although the number of 1 1/2 year old bucks killed has gone down, I suspect that the button buck being killed are in effect taking their place to some extent. Does the game commission feel this is a problem?

The Game Commission was concerned that button buck harvest would increase with the changes (antler restrictions & concurrent season) that occurred to deer seasons in 2001 and 2002. In an effort to help hunters identify button bucks from does, an article entitled “Consider Letting That Button Buck Walk Away” was run in the Hunting and Trapping Digest until this year. After 7 years of concurrent seasons and 6 years of antler restrictions, the percentage of button bucks in the harvest has not changed from pre-2001 levels. Button bucks consistently make up between 21-24% of the antlerless harvest annually.

Does the white-tailed deer eat wild Teaberry, either the berry or the leaves?

Teaberry and wintergreen are listed as deer resistant on some gardening websites. However, it has been observed in Pennsylvania that deer do eat teaberry fruit and the plant itself in some areas of the state. Consumption of the teaberry plant by deer likely relates to the availability of other more palatable plants.

What is the purpose of the Antlered only firearm season in WMUs 2D, 2G, 3C and 4B, for the first week of Firearms season?

In April 2008, Pennsylvania’s Board of Game Commissioners authorized a change in the firearms season in 4 Wildlife Management Units (WMUs) for the 2008-09 hunting seasons. In WMUs 2D, 2G, 3C, and 4B, the firearms season will change from a 12-day antlered and antlerless season to a 5-day antlered only season followed by a 7-day antlered and antlerless concurrent firearms season.

When authorizing the season change, the Board of Game Commissioners noted in the regulation that the “season changes in WMUs 2D, 2G, 3C and 4B are for the purpose of a 4 year study…” This study was designed to answer the following questions concerning the change from a 12-day concurrent firearms season to a 7-day concurrent firearms season: 1) How will antlerless harvest change? 3) Will hunter satisfaction increase? 2) Will hunters see more deer? 4) Will age structure of the antlered harvest change?

A report on conclusion of the study of the study can be found here.

How healthy is the deer population in general in Wayne County? This is where I hunt.

Wayne County is in two different Wildlife Management Units. So the answer will depend on if you are hunting WMU 3C or 3D. A goal of Pennsylvania’s deer management program is to maintain or improve deer herd health. Assessing the health of the state’s deer herd is no small task. The one health measure, which research has proven to be related to deer population health, is reproduction. Female deer in good physical condition produce more fawns than those in poor physical condition. Fifty years of research shows that measures such as pregnancy rates and embryos per doe provide direct information about deer health. The Game Commission uses these two measures to assess the health of the deer herd in each WMU.

The latest data for WMU 3C shows that deer health is “at target” which means that does are producing at least 1.5 embryos/adult doe. WMU 3D is considered “below target” as does in this unit are producing less than 1.5 embryos/adult doe. A closer look at deer management measures for all WMUs can be found in the Deer Chronicle, Summer 2008.

How old is a PA whitetail known as a button buck? Is it possible it could have been born in June and have buttons in October? A friend of mine just took one in archery thinking it was a doe, it field dressed about 40 lbs.

A button buck is between 5 to 8 months old. In the northeast, average field dressed weights for fawns ranged between 37-80 lbs. Male fawns born in the spring have no antlers their first fall. They do however develop pedicles from which their future antlers will grow. As these pedicles develop, they are commonly called “buttons”. The buttons are cast the following spring before the first real set of antlers begins to grow which is just before their first birthday

Is it ok to eat the liver of a deer?

As our wildlife veterinarian likes to say the liver is the “oil filter” of the body. In addition, it is the site of over 100 enzymatic and chemical processes relating to nutrition. The liver detoxifies the body, so often has higher than usual populations of pathogens and toxins destined for elimination. It can also be the site of parasitic infections. In spite of this, many people relish the liver and suffer no apparent side effects.

Antler restrictions are killing our best genetics by harvesting 6 & 8 pointers 1.5 year olds. What do you think?

Antler restrictions have been a positive for Pennsylvania’s deer management program. Since antler restrictions started in 2002, yearling buck survival has increased (from 15% to 52%), harvest of adult bucks has increased (from ~20% to ~50% of total buck harvest), and hunter support has increased (from 57% to 63%). However, there are still criticisms, many of which center around genetics. The argument that we are removing our “best” yearling bucks from the population, which in turn is affecting population genetics, is common. However, when we take a closer look, with the help of new technology and research, the genetics concern is unfounded.

First, deer are wild animals in an uncontrolled environment. Unlike a bull in a pasture full of cows that can’t run away, a buck’s world is full of competition. Bucks compete with each other and must compete for receptive does. Genetics research has shown that yearling males are participating in breeding even in populations with 50% of males being 3.5 years old and older. Since most of Pennsylvania’s bucks are harvested during the gun season and AFTER the breeding season, a yearling buck that is removed has likely already had the opportunity to breed and pass on his genes.

Second, recent research has shown that the amount of growth in the first set of antlers in white-tailed males is a poor predictor of antler growth at maturity. A study conducted over 10 years which followed hundreds of wild, free-ranging white-tailed bucks from their first set of antlers found that by the time bucks reached maturity (4.5 years old), there was no difference in antler measurements between those that had spikes or 3 points as yearlings compared to those that had 4 or more points as yearlings. This suggests that spike and 3-point yearlings can grow the same size antlers as yearling bucks with 4 or more points. All have the capability to produce large antlers at maturity.

Third, let us not forget that all deer receive genes from both their parents. To date, no one has classified the genetic contribution of a doe to her male fawn’s antler growth. And in Pennsylvania, there is no harvest selection on adult does. Their removal is “genetically” random.

Even if we wanted to alter the genetics of Pennsylvania’s deer herd, it would be extremely difficult to do.

I know determining the actual date of the rut in a certain area of the state is not an exact science. However, is there any way to determine approximate dates for the rut?

The deer mating season in Pennsylvania begins as early as September and can last into February. Most adult does are bred in November, with fawn breeding extending through December into February. The Game Commission has collected conception data over the last 8 years (2000-2007) and 90% of does are bred between October 16 and December 16 with a median conception date of mid-November (November 11-17). This information can be found in our annual report 21001 and in a 2002 Game News article entitled “When is the rut?”

I have met several gentlemen on a chat forum from PA that claim local biologists tell them to shoot fawns because they have less of a chance for survival through the winter. Is this true?

PA Game Commission has never recommended hunters shoot fawns because they are less likely to survive the winter. In fact, the Pennsylvania Hunting & Trapping Digest has included an article entitled “Consider Letting That Button Buck Walk Away” which describes the difference between fawns and mature antlerless deer for many years.

The recommendation to shoot fawns because of lower winter survival originates in northern states with severe winters. Fawns are more vulnerable to winter mortality in severe weather. In Pennsylvania, we have severe winter weather in some areas during some years. However, for the most part, Pennsylvania’s winters are not severe enough to substantially reduce fawn survival in most years.

For these reasons, we would not recommend hunters shoot fawns in Pennsylvania.

How often do mature bucks mate in a season? How often do the largest "Monarch bucks mate in a season"?

New technology is revealing more about the white-tailed deer than biologists 50 years ago could even imagine. Animals can now be genetically identified. Research involving genetics has shown multiple paternity and yearling male breeding in all populations that have been studied. The long standing model of deer breeding ecology was that mature, dominant bucks monopolized all the breeding activity, excluding participation by younger males, especially yearlings. But genetics research has shown that yearling males are participating in breeding even in populations with 50% of males being 3.5 years old and older. And most males only sire one litter. With most females coming into estrous at the same time, it is impossible for one buck to dominate all breeding activity. However, this does not mean that he has only mated with one doe.

Females play a role in breeding as well. Until the genetics spotlight was turned on, it was assumed that twin or triplet fawns were full siblings. However, there is about a 20-25% chance that litters with multiple fawns are sired by different bucks. This means females are mating with multiple bucks during her estrous cycle.

The bottom line is that mature bucks have a lot of competition and the biggest ones are no exception.

My question is, will whitetail bucks return season after season to previous locations of scrapes and/or possibly use the same scrape location pattern of the previous season?

The most complex signpost bucks use is scraping. It is used most intensely just before the peak of the rut. A full scrape involves 3 things: branch marking, pawing, and urination. A scraping sequence starts with an overhanging limb on which a buck will rub his forehead or preorbital gland. If the mood strikes him, he’ll even rattle the branch with his antlers. He then takes the twig in his mouth and moistens it, thereby leaving his mark and detecting that of others using the scrape. After this, he clears a 3- to 6-foot diameter circle by pawing the ground. The buck then steps into the cleared circle and urinates onto his tarsal glands while rubbing them together. Usually only mature, dominant bucks produce any significant number of scrapes.

Some scrapes may be used annually. However as forests change, so may scrape locations as they require a marking branch at the proper height. Rubs, on the other hand, only require a tree and, if it’s not cut down, the same tree will be there year after year. So some rubs are historic being used annually.

My trail camera took a photo of a doe with several black spots or blotches on her hide. There was some on the ears too. Do you have an idea what is causing this and is it normal?

A deer’s summer coat consists of reddish-colored guard hairs. Unlike their winter coat, there is no underfur. Without underfur, warm air is able to move away from the skin by convection keeping deer cool during the dog days of summer. With this light coat, many imperfections may be seen by an observer. First, deer skin is not necessarily white or light colored. Just like the family dog, a deer’s skin can be dark in color and this can show through its summer coat appearing blotchy in spots where the hair is thin. This is especially noticeable on the back of the ears. Second, summer time is bug time. Screened-in porches and bug spray is a luxury that deer do not have. Ticks and a list of biting flies to numerous to name constantly hound deer throughout the summer. These too can be seen in some cases on the summer coat of the deer clustered together. Unlike cows, deer don’t have a long tail to swish flies away and deer are often seen twitching or stamping their feet to disrupt the fly’s feast. Third, stray branches, fences, and other natural and manmade objects can scrape and chafe. Finally, deer do get skin diseases from time to time. This is normal and healthy animals will recover. However unless the deer is physically examined, it is difficult to say which of these is the cause of the darks spots.

Why did the Game Commission change from smaller county-based units to larger WMUs for deer management?

First, WMUs were not designed specifically for deer management. They were designed for all wildlife species management programs.

Second, it is commonly argued that smaller WMUs are better than large WMUs. This would be true if enough data were collected in each of the small WMU to support management recommendations. Unfortunately, limited time, personnel, and resources combine to prevent adequate data collection at county, or smaller, management units. As a result, larger WMUs were implemented to provide data for making defendable deer management recommendations. The PGC previously combined 67 counties into 31 groups to improve precision of deer-related estimates. Twenty-two WMUs improves precision of and increases confidence in management recommendations within each unit.

Third, unlike the 31 county groups, WMUs are created considering land use, land ownership, urbanization, and geography. WMUs are more similar within themselves than they are to other units. County groups were simply based on map location. Also, defining unit boundaries by roads and other physical features like rivers makes them easily recognizable. County boundaries are lines drawn on a map. There are no lines in the woods between counties.

Finally, we recognize there will be deer-related problems on a smaller scale that cannot be addressed within the WMU system. For this reason, the Deer Management Assistance Program (DMAP) is available to landowners who want to reduce deer impacts. For those landowners who want to increase deer numbers, they can do that by limiting hunter access or harvest without a formal PGC “cold spot” program.

From my observations last hunting season, the deer herd was hit hard by EHD in the East Findley area of Greene County. Has anyone looked into the disease and can it spread to the rest of the state?

Epizootic Hemorrhagic Disease got the attention of many people in 2007. This disease is caused by a virus. The first documented outbreak of hemorrhagic disease was in 1955 in New Jersey. In its acute form, it causes sudden loss of appetite, disorientation, weakness, respiratory distress, and rapid death. Die-offs occur suddenly and almost exclusively in late summer and early fall, coinciding with peak populations of the insects, called midges or “no-see-ums” that transmit the disease. Hemorrhagic disease is common in the southeastern United States and outbreaks have been documented in Pennsylvania and many other states. Losses due to EHD have occurred in Pennsylvania in 1996, 2002, and 2007. While mortality associated with EHD may seem dramatic, local populations rebound quickly after an outbreak. Many infected deer live and show only mild signs of disease or no signs at all. And animals that survive an EHD infection develop antibodies that protect them from future outbreaks.

More information, including a brochure, can be found on our EHD webpage.

I volunteer at a local park in lower Bucks with a fairly large population of deer. Recently we have planted some young shade trees 3/4" to 1" DBH along the jogging path. We would like to protect these & other small trees from rub damage by placing sections of corrugated PVC drainage pipe around the trunks, but only want to leave the protection on for the duration of the rut.

When would you suggest providing the trunk protection? When could it safely be removed?

The peak of the rut occurs in mid-November for adult females and the first of December for fawn females in Pennsylvania. Collectively, 89% of all females are bred between October 16th and December 16th. While this might represent the majority of rut, rut activity begins prior to these dates. The hardening of a bucks antlers and the loss of velvet occurs in September. This is when bucks begin to make rubs. Rubbing involves tearing and rubbing the bark off bushes and trees. Rubbing during and shortly after velvet loss is violent. After this initial period is over and the rut progresses, rubbing evolves into its more typical, highly visual signpost. Age also plays a factor in rub making. Older bucks rub much larger trees. Yearlings typically rub saplings no more than 2 to 3 inches in diameter. Compare this to a mature buck who may rub pole trees 6 inches or larger.

Therefore, in order to protect your new trees, action must be taken in September before velvet loss and continued through December.

Do the PGC Biologists and staff still use the eruption-wear method for aging deer?

The age of white-tailed deer can be estimated by tooth wear and replacement patterns. Like children, deer replace their teeth in a systematic fashion. Age can be determined by the stage of tooth replacement through 2.5 years old. Once all “baby” teeth have been replaced, determining the age of a deer relies on tooth wear. As a deer gets older, their teeth wear down from grinding their food. These wear patterns are generally predictable to a point. There are many factors that influence individual tooth wear patterns of deer: type of food eaten, soil types, injury, individual chewing patterns, etc.

Once all teeth are replaced, it is difficult to determine the age of a deer with certainty based on wear patterns alone. This is why the Game Commission ages deer into only 3 categories when collecting harvest data from processors every fall. Trained Game Commission deer agers can reliably and consistently age deer to 6 months (fawns), 18 months (yearlings), and 30+ months (2.5 years or older) using the tooth wear and replacement method.

When do white-tailed fawns start loosing their white spots and growing in their new fur? Do they loose it over their entire body or start at the head and neck area?

Fawns are born with little strength and coordination. Their reddish brown coat dappled with white spots serves to protect them during their most vulnerable period of life. But as the days grow shorter and fawns grow stronger, they out grow this birth pelage. In August or September, fawns start the molting process. This is related to the time of weaning but the bigger trigger is daylight. The molt begins at the head and neck continues down the spine and ends with the legs. The white spots are still visible as the gray winter coat grows in. A keen eye may still detect the hint of spots late into the fall on a fawn’s first winter coat.

We recently acquired a lease on 1,080 acres near Roulette in Potter County. The property has a lot of logging roads with good sun, but sandy soil in places. What should we plant to help sustain and attract deer? Any help would be greatly appreciated.

Wildlife food plots are a popular topic. One good reference is available on this website under Habitat Management. Click on Food Plots. Since this area has sandy soil, the section about annual plantings for poor sites is most appropriate.

Hi. We all know that deer have one stomach, but it is chambered in multiple sections. What would happen to a deer if one of the chambered sections fails to work properly? Would it still be able to carry on a productive life?

Much depends on which of the four chambers is affected. If it is the reticulum (#1), the disease may be as minor as temporary indigestion with possible weight loss. If there is a foreign body that can penetrate or severely inflame the wall of the reticulum that rests against the diaphragm there can also be extension of this inflammation to the lungs which are just on the other side of the diaphragm. The resulting progressive pneumonia can result in decreased lung function or death. If it is the rumen (#2) it can result in everything from indigestion to a very low pH (acidosis). Disruptions of the rumen environment can lead to a die-off of the normal bugs that live there and are responsible for fermenting the feed. Again depending on the severity of the disruption you can see scarring of the rumen wall, overgrowths of fungi that migrate to the lungs and cause a severe pneumonia, or a shock-like condition that can result in death either quickly, or at least resulting in a shortened life. If it is the omasum (#3) usually it is because of an obstruction (as with a placenta or a plastic bag), and if not relieved can stop the whole function of the stomach and result in death. If it is the abomasum (#4), which is most like our true stomach, there can be ulcers that either heal when the problem is corrected, or actually perforate the wall and contaminate the abdomen resulting in pain, infection and possibly death. Many problems associated with stomach alignments in a deer stem from deer being fed supplemental food to which they are not adapted. Bottom line: allow the deer to eat what nature has intended and to which it has evolved for eons and bellyaches will be minimal. For more information on why feeding deer is harmful, visit Living With Whitetails on this website.

Deer Biologist