White-Tailed Deer… Too Many?! …Not Enough?!

By: Bill Ishmael, Retired Wildlife Biologist of 30 years

White-tailed deer are the most widely-distributed and numerous big game animal in North America. Although the Badger is the official Wisconsin state “animal” symbol, the White-tailed deer is the official Wisconsin state “wildlife animal” symbol. Deer have always been a part of Wisconsin post-glacial ecosystems and recent estimates show that we share our state landscapes with about 1.5 million of them. But, like anything else, too much of a good thing can be bad.

As a prey species, deer have evolved an incredible reproductive potential, leading to rapid increases in their population, even when their preferred food sources have started to dwindle. Deer populations on the productive soils of southern Wisconsin can increase annually by a factor of 1.5 or more. So, if you have 20 deer on your property in April, there will likely be 30 by September. If most of these deer survive the hunting seasons, predation and car-kills, you could have 45 deer by the second fall. This effect of “compound interest” was clearly demonstrated at the George Reserve in southern Michigan between 1927 and 1933 when a small herd of 6 deer increased to 160 in just 6 years within this fenced preserve!

Landowners who want to improve the “health” of their land need to take in to account the impacts deer can have on their native, ornamental and agricultural vegetation as well as the impacts deer can have, indirectly, on other species of wildlife landowners wish to promote through their land management practices. Other than a few small elk herds in northern and central Wisconsin, white-tailed deer are the state’s largest wild herbivore and, through their selective browsing, deer can have a detrimental effect on the diversity and abundance of native vegetation communities wherever they exist, even where deer exist in relatively low numbers.

The average deer in Wisconsin eats about 6 pounds of food per day or roughly 1 ton of forage per year. So, if you have 20 deer on your property, about 40,000 pounds of forage will be consumed by deer each year. Deer are “sampling browsers”, eating a wide variety of vegetation, usually starting with the most palatable and nutritious foods and working their way down the list from there. Their ruminant gut allows them to quickly consume large quantities of food and then head for cover where they can “ruminate” to continue the digestion process.

In most cases, landowners won’t recognize the impacts deer are having on their native vegetation communities because the native plants are no longer there or the plants are prevented from blooming by continual browsing. You can’t see what’s not there. The best way to get a first-hand view of the impacts deer have on vegetation is to erect small deer-proof exclosures. But exclosures are expensive and need to be maintained for at least 10 years to have a demonstrable effect. An online search of “deer exclosures” will bring up dozens of photos of exclosures that clearly demonstrate the effects deer have on native vegetation. One of the many informative websites describing deer impacts to native vegetation can be found at http://www.aviddeer.com.

Through selective browsing, deer can reduce or entirely eliminate native plant species from your property, opening the door for less palatable invasive plant species such as honeysuckle, buckthorn, barberry and garlic mustard. Deer can even facilitate the spread of these invasive plants by carrying seeds in their hooves and fur. For instance, have you noticed that infestations of garlic mustard on your property most often first appear along deer trails and in deer bedding areas?

It’s important to remember too that deer diets shift dramatically through the seasons. The lush green foliage of summer and early fall may give you the impression that there’s lots of deer food out there. However, if your woodlands are overbrowsed by deer, there may not be many palatable or nutritious plants left. By late fall and early winter deer must necessarily shift their diet from green herbaceous plants to woody browse. Acorns (and other mast varieties) are a very important staple in a deer’s annual diet but acorns are the preferred food of many wildlife species and, by winter, what’s left gets buried under snow and ice. By Christmas deer have usually switched to a diet of woody browse, targeting oak seedlings, hazelnut, other native shrubs and even conifer seedlings such as white pine for the 3-4 month span of winter. Regeneration of your forests and a diverse shrub understory may be difficult or even impossible in the presence of high deer numbers.

A comprehensive approach to restoring and maintaining native vegetation on your property should include a deer management plan. Each property is different in terms of it’s capacity to sustain deer numbers at a specific level and there is no “one-size-fits-all” rule for managing deer on your property to reduce impacts on native vegetation and forest regeneration. Since large predators such as wolves, mountain lions, and bear no longer exist in southern Wisconsin (at least not in the numbers that could influence deer survival and population growth rates) regulated hunting has become the primary tool for managing deer populations. Fencing your property to keep deer out is expensive, impractical and not very aesthetically pleasing. Planting deer food plots to supplement their diet or buffer impacts on native plants species is also expensive and only serves to maintain artificially high deer numbers. Food plots occupy land that could be devoted to native plant restoration and most food plots, unless they are several acres in size, are usually devoid of food by late December anyway, leaving an artificially high number of deer “stranded’ and forced to put even more pressure on native woody browse species each winter.

Controlling the number of deer on your land, through regulated harvests during the annual fall hunting seasons, is just as important for managing the vegetation communities on your property as timber harvests, invasive plant control, tree/shrub planting or native prairie restorations. Professional Wildlife Biologists keep track of deer population estimates and hunting season harvests and, over decades, have found that, in order to cause a decline in farmland deer populations, hunters need to harvest at least 2 antlerless deer for every antlered buck harvested on their property. Harvests of 1.5 antlerless deer per buck will usually maintain the deer population while harvests of 1 or less antlerless deer per buck will result in a population increase. Landowners may need to adjust their deer harvests, up or down, based on observed impacts to native vegetation. Remember, deer have an incredible reproductive potential and populations can quickly grow to the point where controlling their numbers becomes increasingly difficult.

Projects, Update

Fenceline or Secret Savanna?

Every winter the Quercus crew has a few projects removing fencelines. In the midst of the project, it is not unusual to find wise old oak trees, like this one at the Patrick Marsh Conservancy in Sun Prairie. Once the brush is removed, the feel of the open grasslands and mature oaks can almost transport you back in time to the historical savannas.

Have a secret savanna on your property? Give us a call or email to schedule for Winter 2020.

Patrick Marsh before       Patrick Marsh after

Conservation Topics

Prescribed Burning and Deer Hunting

We have had many prospective and existing clients that are concerned about the affect of restoration practices on deer hunting, especially in regards to prescribed burning in their woodlands. A monster buck, along with 2 other bucks, were all harvested opening weekend 2016 in a freshly burned open oak woodland (pictured below)! This woodland was burned the week before opening weekend and it did not adversely affect the hunters on this property from shooting 3 nice bucks in the areas that were burned. In the pictures you can see the freshly burned forest floor that we refer to as “the black.” This woodland has had most of the invasive brush removed, so it is open in structure.

Occasional fire is what shaped the landscape of SW Wisconsin before European settlers began suppressing wildfires. Oak woodlands, savannas, and prairies are historically what covered our landscape and are all fire-dependent ecosystems. Prescribed burning is a way that we can return fire to the landscape and begin to improve the health of our lands.

When burning in woodlands, the fire behavior is much different than the fast moving 15+ foot flames that are common in prairies. In woodlands fire is much more subdued with an average of 2-4′ flames and a much slower rate of spread. This low intensity burn helps discourage herbaceous invasive species, thin out brush and young trees, and consume some of the dead and down woody debris which helps return nutrients to the soil. The brush and young trees that are “top-killed” will re-sprout the following year, producing young shoots that can provide a food source for deer and other wildlife. Prescribed burning is a great tool to help restore your woodland and improve habitat for deer and many other wildlife species.

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2017 Spring Burn Season in review

The 2017 spring burn season started out pretty wet. We would get a few days of rain followed by a day or two of drier weather that we could burn, then the rain returned. The weather eventually began to cooperate, though we were seeing a quicker “green up” so we knew we had our work cut out for us. 53 burns on our list and the crew kicked it into high gear.

Our 2017 burn season looked differently than in the past. 3 members of the crew have received advanced training in Wildland Fire and are certified burn bosses. This allowed the Quercus crew to split into two different directions on most days and really contributed to us getting very close to completing all the burns on our list. Our crew members worked many long days, all while conducting burns in a safe, efficient, and professional manner.

Spring 2017 Summary:  49 burns, 86 burn units, 1623 acres, 18 burn days.


2016 Spring Burn Season

The spring 2016 burn season has arrived and the Quercus Crew has been updating burn plans, applying for burn permits, preparing equipment, and installing firebreaks. We conducted our first burn of the year north of Cross Plains nearby Indian Lake last Friday. We are hoping for great weather this spring to try to complete our growing list of prescribed burns. Keep an eye out for smoke on the horizon!

Check out this incredible video from one of our burns last year: https://vimeo.com/158821488

Closed off unit 1.  Photo by Michael Kienitz
Closed off unit 1.
Photo by Michael Kienitz


Is your land due for a Prescribed Burn?

Is your land due for a prescribed burn? Quercus has begun the process of installing firebreaks and composing burn plans for the upcoming burn season this fall and also Spring 2016. If you have a prairie, woodland, wetland, or CRP field that you would like burned, NOW is the time to get on our Burn List. By confirming early we will be sure to get your firebreaks installed, burn plans written, and any necessary permits acquired. Give us a call or shoot us an email today! We look forward to hearing from you and helping you manage your land.

Phone: 608-767-3553   Email: office@quercus-ls.com

Closed off unit 1.  Photo by Michael Kienitz
Closed off unit 1.
Photo by Michael Kienitz

Projects, Update

Looking back on the burn season

This spring the Quercus Crew had another excellent burn season and we were able to check off all of our burns on our list! We burned 36 sites over 25 burn days and approximately 800 acres! It was a busy season and we were lucky enough to have a very talented photographer document two of our burns. One at the UW Lakeshore Preserve and one at a private property in the Ridgeway area. I hope you enjoy these photos as much as we do – Check them out at: http://www.bobbisolum.com/Quercus-Burns

If you would like the Quercus Crew to burn your property contact us in order to get on our list! Our schedule fills up quickly, and we try to prioritize burns based on the date we confirm them.

Office@quercus-ls.com      608-767-3553

Conservation Topics, Projects

Holy Smokes and Drones

On Wednesday Quercus burned at Holy Wisdom Monastery in Middleton, WI and had another safe, successful day on the job. The Monastery has 7 units totaling 85 acres of quality prairie on their property. 

The Quercus Crew had the privilege of having Michael Kienitz (photo4u@michaelkienitz.com)  documenting their burn at Holy Wisdom with his incredible drones! It was amazing to see how well his drones handled the rising heat from our flames. The images are breath-taking and a perspective that we normally would never see! Check out the handful of photos from this day and his website for his other works (idroneon.com).

Wisconsin Channel 3000 stopped by and interviewed Jim about our burn. Check it out here!

Conservation Topics, Projects

Documentary featuring Quercus at the 2015 Wisconsin Film Festival!

Last spring a UW Madison student, Elizabeth Wadium filmed a short documentary that features Quercus burning at Pheasant Branch and Lakeshore Nature Preserve called “Prairie Burns.” It is being screened at this year’s 2015 Wisconsin Film Festival!  Screening times are Thursday, April 9th at 8:45pm (Union South) and Friday, April 10th at 3:15 (Sundance Cinemas) before a showing of “Uncle John.” Come check out the Quercus Crew in action!


The 2015 Spring Burn Season has ARRIVED!

Today marks the first day of the Spring Burn season for the Quercus Crew! We are all excited to get started on our list of burns that are located in Western Dane County, Iowa County, and Columbia County. The crew are busy preparing the equipment and filling tanks with water and drip torches with fuel. For those of you who haven’t scheduled your burn with us yet, not to worry, there is still time to add your name to our list! If you see smoke on the horizon, it could be the Quercus Crew hard at work. Enjoy the spring!

Wet lining. Spring 2014
Wet lining. Spring 2014