Useful Facts about Deer and Fences
Why Deer Jump – Or Don’t
Among the most compelling facts about deer and fences is that an adult white-tailed deer can really jump. In fact, a white-tail in a panic can sometimes clear a 7-foot fence. But under ordinary circumstances, even when attracted by aromatic browse, deer rarely jump this high. In fact, they often won’t even jump a 6-foot deer fence – for several reasons.
First, why should white-tailed deer, black-tailed deer, or any other deer species take the trouble to jump a deer fence when they can go through, around, or under it–which is in fact what they usually do. Second, what goes up must come down. Would you voluntarily jump off a third-story balcony–especially if you might land in a bunch of bushes or didn’t know how congenial your landing spot would be? For this same reason, Nature makes white tailed deer reluctant to jump high–a reluctance that discourages them from vaulting 7-foot fences even when they can.
What Deer See
Another reason deer don’t normally jump deer fencing: They have real trouble seeing the fence top. Deer see best in the yellow, deep blue and certain ultraviolet portions of the spectrum, and both black polypropylene deer fencing and black pvc-coated metal hexagrid deer fencing reflect these wavelengths poorly. In addition, deer have limited depth perception. Their eyes are on the sides of their heads (for wrap-around peripheral vision to spot predators), so their binocular vision is sacrificed and their 3D sense (especially for nearby objects) is weak. Thus, they have difficulty telling where your barely visible deer fence leaves off and the trees and sky begin. And that means they generally won’t try to jump the fence, any more than you would try to vault a fence at dusk that you could barely see–one that might be 4, 5, or 6 feet high.
Of course, deer pursued by coyotes might try to jump anything, just as you might jump off the third-story balcony of a burning building. So it’s important to understand that your deer fence is a tool to deter deer with limited incentives, and it helps to know what the incentives are. For example, Are there coyotes or dogs in the neighborhood that enjoy chasing deer? Is your new fence blocking an established deer path that large numbers of deer habitually use? Or are the deer likely to be starving in winter and desperate for food they can see and smell inside the fence? As we will see, such considerations have a bearing on what sort of deer fence to install and how well you can expect it to perform.
More Facts about Deer: Effects of Deer Pressure
A more general concern of deer fence builders is the degree of pressure from white-tail deer or other deer species (most notably black-tail deer and elk). The presence of lots of deer in the neighborhood of a deer fence makes it more likely that deer will periodically bump into the fence, become familiar with it, and try to penetrate it–not so much by jumping as by punching a hole in the fencing or more commonly by finding small available holes made by rabbits or ground hogs that they can then enlarge by pushing through (see Fence Penetration: The Deer-Small Animal Combo). Of course, white-tail deer pressure tends to get focused when the deer have an established path interdicted by the deer fence. If a small rarely used deer path crosses the path of your intended fence, that’s not a major problem. But if the path looks like it was made by a herd of buffalo (but you know it was made by deer) then the path is a big factor you must respect–even to the extent of letting the deer have their path and erecting your deer fencing on either side of it (see Installation: Dealing with Deer Paths).