Deer as Pests in the Urban and Suburban Pacific Northwest

White-tailed deer

By Dan Stein, 2006; Updated 2019

Deer are the largest mammals you are likely to find in your backyard if you live in many urban or suburban areas of the Pacific Northwest. As human populations expand into forested areas, deer have become a much more common sight.

Having deer in your neighborhood is a mixed blessing. On the one hand, there is the wonder of having a wild, majestic animal close enough to observe in detail. And then there is the frustration of watching that deer destroy your garden and your expensive landscaping! Fortunately there are ways of minimizing the damage deer can do in your yard.

Not Just Garden Pests

Deer are a very serious problem along highways, involved in nearly one and a half million car accidents nationwide each year [1]. Reducing deer-car crashes is an important priority for highway departments everywhere and there are no easy solutions. The only proven way to reduce deer-vehicle accidents is to slow down when driving in areas where deer may be present and to stay extra alert.

And while only a minor problem in the Pacific Northwest, deer are known to harbor ticks that can carry and spread Lyme Disease. In Oregon,  roughly 40 to 50 cases of Lyme Disease are reported each year [2]. In Washington, less than ten reported cases each year are actually acquired in Washington, whereas the rest are contracted from tick bites that occur in the northeast or upper midwest United States [3]. Still, Lyme Disease is a serious condition with a wide range of acute and chronic symptoms, and it is likely to spread. Refer to NCAP’s website for tips on dealing with ticks: http://www.pesticide.org/ticks. Consult your local health department to find out if Lyme Disease has been reported in your area.

Three Different PNW Species

Depending on whether you live on the west side or the east side of the Cascades determines which of three species of deer you are likely to encounter. On the east side, including Idaho and Montana, the white-tailed deer and mule deer are predominant. West of the mountains, a sub-species of mule deer, the black-tailed deer, is most common [4].

Mule deer are the largest, with bucks weighing up to 250 pounds and does averaging 150 pounds. White-tailed and black-tailed deer are similar in size. Bucks for both species weigh up to 200 pounds, and does average around 120 pounds [4].

Black-tailed and white-tailed deer tend not to migrate much, usually staying within a small area of less than one square mile. Mule deer, on the other hand, often migrate long distances, especially through their winter range [4].

Each species has its own food preferences. See the publication, Managing Deer on Small Woodlands, for a list of the preferred food plants of each species [5]. When food is scarce, deer will eat many plants not usually found in their diet.

Deer Life Cycle

All three species have similar life cycles [4]. Deer breed in November and December and have fawns from May through July. A doe usually gives birth to one fawn, though twins are not uncommon. Triplets are rare. Male fawns start to develop buttons at six to eight months which over time will develop into antlers. Adult bucks grow new antlers each year. Antler growth begins in early spring and antlers are shed in December or January. Deer can live up to ten years, but most don’t live more than five.

One note about fawns: It is not uncommon to find a fawn by itself in the woods and to think it must be “orphaned.” Many times a parent is hiding nearby. Do not try to “rescue” these fawns unless the mother does not return for more than eight hours [4]. Call your local Department of Fish and Wildlife if you believe you have found an orphaned fawn.

Black-tailed deer

Controlling Deer

It is easy to forget, especially in urban environments, that deer are wild animals with excellent survival instincts that all prey animals possess. This makes them very wary and difficult to control. And sometimes there is the other problem. Deer can become so accustomed to people that they lose their survival instincts and become hard to chase away! This also makes them difficult to control. Working with deer always requires patience and tenacity. Many times it will take a combination of approaches to get the level of control that makes you happy.

Fencing

Fencing is by far the most effective method of controlling deer damage. In most areas, it takes an eight foot tall fence of woven wire to effectively exclude deer [6]. This is an expensive solution however, and may not meet your community’s sense of aesthetics.

Electric fences of various designs can also be used. These are usually less expensive than woven wire fences though are not always as effective. Special care must be taken with children around electric fences. Even though electric fences have a good safety record, your child will surely let you know if he or she gets shocked!

There are also various types of angled fences, some with a “trip wire” that also can be effective. Managing White-Tailed Deer in Suburban Environments: A Technical Guide lists many references for different design options for fences [7].

Using mini-barriers to protect individual trees, shrubs, or a vegetable garden, may make more sense then fencing an entire yard. Floating row covers or “reemay” may also help protect vegetables [4].

Repellents

Repellents, usually odor and taste deterrents, can be used to protect small areas of valuable vegetation [6]. There are a wide variety of commercial products for sale for this purpose, as well as some ‘home remedies’ such as bars of soap. The problem with all repellents is that they must be reapplied on a regular basis, especially during rainy periods. Ask in your local gardening store what products are most effective in your area.

Dogs

Many anecdotal reports suggest that dogs can be effective in controlling deer. Do keep in mind that a dog inside watching TV with you won’t be doing much good protecting your yard. One source mentions that a pig run inside your yard may deter deer [7]. (Check with your local animal control agency first if you are seriously considering this.) Nevertheless, a dog run along a fence line or a “dog trolley” may be helpful. Please keep in mind that it is illegal in many areas to allow dogs to run free chasing deer off your property. This is considered harassment by most Departments of Fish and Wildlife [8]. Dogs should be kept within your fences or controlled with an electronic collar or “Invisible Fence”-type system.

Deer-Resistant Plants

In areas with large deer populations it probably makes sense to landscape with deer-resistant plants. These are plants that for the most part, will avoid serious deer damage. Keep in mind that no plant is deer-proof. In times of famine and as habitat shrinks, deer will become more adventurous and will eat many plants considered outside their usual diets. Most state Extension Services have lists of deer resistant plants for you to look through [4], [9], [10].

Scare Tactics

If you want to make enemies with your neighbors fast, install a propane cannon in your backyard that makes random explosive noises to scare away deer (and birds). While these are used in large farming operations, they are— of course!—not appropriate for use in town. Other scare devices, such as strobe lights, fireworks, and loud radios turned on and off randomly [7], won’t make you any friends either. One relatively new scare device that won’t offend neighbors is the motion-activated sprinkler [8]. A moving deer in your yard quickly activates a sprinkler that gives it a three second blast of water. While raccoons are reported to play with such systems, deer avoid them.

Don’t Feed Them!

There is no surer way to end up with a life-long deer problem than to feed deer in your yard. Feeding also attracts predators such as cougars into your neighborhood, and can also contribute to the spread of deer diseases [8]. If you have neighbors who are feeding deer, you can call your local Animal Control board or the Fish and Wildlife Service and they will come out and talk to them.

Don’t Forget to Enjoy Them

It is too easy to label some creatures as pests, and to forget that all of Nature has a right to exist. It is not the deer’s fault that we are building our homes on its traditional habitat. Deer are sometimes referred to as “edge” species, meaning they prefer to live where two or more habitats meet. As urban areas expand into the woods, the “edge” keeps moving deeper into the deer’s traditional habitat. We owe them some accommodation for this. Deer are magnificent animals that we can learn to live with and enjoy with a little effort

References & Additional Sources of Information

  1. American Association of State Highway and Transportation Officials. Oct. 12, 2018. State Farm Survey: Deer-Vehicle Collisions Dropping, But Costs Risinghttps://aashtojournal.org/2018/10/12/state-farm-survey-deer-vehicle-collisions-dropping-but-costs-rising/
  2. Oregon Health Authority, Public Health Division. 2017. Fact Sheet: Lyme Disease in Oregonhttps://www.oregon.gov/oha/PH/DISEASESCONDITIONS/COMMUNICABLEDISEASE/VETERINARIANS/Documents/DiseaseFactsheets/lyme.pdf
  3. Washington State Department of Health. Undated. Lyme Disease. https://www.doh.wa.gov/YouandYourFamily/IllnessandDisease/LymeDisease
  4. Washington Department of Fish and Wildlife. Undated. Living with wildlife: Deer.  https://wdfw.wa.gov/species-habitats/living/species-facts/deer#
  5. Watson, K. and M. Schirato. 1998. Woodland Fish and Wildlife: Managing Deer on Small Woodlands. https://westernforestry.org/WoodlandFishAndWildlife/wp-content/uploads/2015/09/deer.pdf
  6. Holtfreter, R., and J. Creighton. 2004. Non-lethal methods for controlling deer damage. Washington State University Extension Service.
  7. Gegner, L. 2003. Deer control options. Appropriate Technology Transfer for Rural Areas (ATTRA). https://attra.ncat.org/attra-pub/download.php?id=150
  8. Yee, Chris. 2006. Personal Conversation. Oregon Department of Fish and Wildlife.
  9. Oregon State University Extension Service. 2012. Deer-resistant plants for Central Oregon. https://extension.oregonstate.edu/gardening/techniques/deer-resistant-plants-central-oregon
  10. Chu, E. 2017. Deer Resistant Garden. Washington State University. https://s3.wp.wsu.edu/uploads/sites/2073/2014/03/Deer-resistant-Garden.pdf

 

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