Hill Country Browse
Article and photos by Steve Nelle (except where noted)
The Texas Hill Country has the highest density of shrub-eating animals in the United States.
Texas is home to about 4 million white-tailed deer, and about half of them live in the Hill Country and Edwards Plateau. In addition, Texas is home to more than 2 million goats, sheep and exotics, and the majority of these live in the Hill Country. These animals depend on browse, the leaves and tender twigs of woody plants, as an important part of their diet.
There are about 200 species of woody plants native to the Hill Country and an average ranch may have 30 – 60 different types. Knowing how to identify, appreciate and manage browse plants is one of the primary jobs of successful ranchers and wildlife managers.
Scientific studies have revealed the importance of browse in the diet of small ungulates, and when it comes to white-tailed deer, browse is the primary part of their diet. Deer also eat mast, forbs and some grass, but browse is what keeps them alive most of the time. Table 1 shows the percentage of browse in the diet of deer, livestock and common exotics based on studies done at the Kerr Wildlife Management Area.
Photo by Wyman Meinzer
The nutritional value of browse ranges from poor to exceptionally good. While there is considerable variation from species to species, the greatest variation is from season to season within a given species. For example, the new spring growth of hackberry contains 25 percent crude protein with high energy value while the old leaves of summer have only 8 percent protein and low energy value. Table 2 lists seasonal protein and energy values of some common Hill Country browse plants.
Most of the region’s browse plants are deciduous, losing their leaves in December and remaining bare until April. During this four-or-five-month period the browse supply is diminished greatly, and this can be a critical time for deer, especially in a dry winter. Fortunately, a handful of browse plants are evergreen containing “antifreeze” compounds in their sap which allows green leaves to persist through winter. Table 3 lists the most important evergreen browse species and their wintertime nutritional quality.
Although the nutritional value of most winter browse is low, remember that deer have reduced nutritional needs in the winter. Bucks are not growing antlers and does are not lactating, so they can survive on lower quality browse.
Another form of winter browse—fallen leaves—are not well understood; and these can provide significant nutrition. Fallen mesquite leaves are often eaten and contain 16 percent protein, although they are low in energy.
Not all browse is created equal and browsing animals are selective about what they consume. With agile lips and prehensile tongues, they can select the individual leaves they prefer. Selectivity and preference is driven by tenderness, nutritional value, taste and the presence of spines or thorns.
New growth is preferred over old growth since it is more tender and nutritious. Older mature leaves are higher in lignin which reduces digestibility, quality and palatability. Think of the difference in eating a young tender pod of okra compared to an old, tough pod. The difference is lignin and the same thing happens with browsers as they seek plants that are most tender and digestible.
Browsing animals have a good sense of nutritional wisdom, consuming plants that will best meet their nutritional needs for energy, protein and minerals. They “know” which plants are more nutritious and which are less nutritious. Given a choice, they will select the most nutritious diet possible from the plants available in the pasture. However, on overpopulated or degraded ranges with poor plant diversity, they are not able to exercise much selectivity because they do not have much to choose from and must eat what is available.
Taste also affects animal preference of different plants. Some plants have no adverse taste, while others have an offensive taste which deters and limits consumption. The chemicals that produce bad tastes often interfere with the digestion and assimilation of nutrients and can make an animal sick if eaten in large amount. Table 4 is a listing of relative preference categories for the common species of Hill Country browse.
Brush vs Browse
Brush has a negative connotation, and most landowners would like to reduce if not eliminate certain brush species. Yet browse is considered a valuable asset and many landowners would like to have more of it. The paradox is that some of the most disliked brush species are also some of the most important browse plants.
Cedar, mesquite and persimmon are three of the most disliked brush species in the region and while not preferred, they are among the most important browse plants due to their abundance. These three brush species are among the top 10 browse plants (see Table 5), often making up one-third of the annual deer diet. Another side benefit of mesquite in addition to its use as browse is the growth of mistletoe, one of the best yearlong deer food plants found anywhere.
Browse management is an important habitat consideration for many Hill Country landowners. The most critical management aspect is balancing the number of browsing animals to the browse supply. Some parts of the Hill Country are so overpopulated with deer and exotics that the browse resource’s future is in jeopardy. In these areas, browse lines are evident on trees, and most shrubs are severely hedged, giving them the appearance of a bonsai plant.
This kind of over-browsing harms the plants’ vigor and productivity and virtually eliminates successful reproduction. Over time, the more desirable species are eliminated and the less desirable species increase. Under these conditions, browsing animals suffer malnutrition and poor performance. The remedy is not to feed deer to compensate for poor nutrition, but to balance the number of animals so that the habitat will improve.
Wildlife biologist Al Brothers, author of the book Producing Quality Whitetails, said, “The most cost-effective way to increase the deer food supply is to decrease the number of animals on the range.” This is especially hard to do in the Hill Country and requires a great deal of determination. It may also require the cooperative management of several adjacent ranches or the construction of a high fence.
For ranches where animal numbers are more or less in balance with the food supply, browse can be renovated by fire or mechanical means. Prescribed fire will top kill some shrubs and force them to re-sprout from the base. This enhances browse production and availability, and the new growth will be higher in nutritional quality. Roller chopping, dragging, hydro-axing or similar operations will do the same thing but are much more expensive.
A staggered program of browse renovation where 10 – 20 percent of the ranch is treated every other year is a good way to boost browse production and quality. Available browse production can often be doubled or tripled with an ongoing program of burning and/or mechanical renovation.
Selective brush management is also a good way to thin out the less desirable browse species such as cedar and allow the better species to increase. The goal should not be to eliminate cedar but to shift the dominance to other higher value browse. When cedar or other brush is mechanically removed, it is extremely beneficial to leave dead slash scattered on the ground rather than raking it into piles and burning it. The slash provides thousands of protected niches where desirable plants have a chance to get started.
Browse is an economically and ecologically important resource. Revenue generated by deer hunting is what keeps many Hill Country ranches viable, and those deer live mostly on browse. When landowners do a good job of managing browse, they also simultaneously protect biodiversity and maintain habitat for hundreds of other species.
Table 1 Browse Consumption Percentage of Wildlife and Livestock in the Hill Country
Seasonal Range of Average Yearly
Animal Browse Consumption Browse Consumption
Whitetail 32 - 100% 72%
Goat 26 - 95% 71%
Sika 34 - 70% 54%
Fallow 8 - 75% 33%
Axis 2 - 50% 28%
Blackbuck 2 - 60% 27%
Sheep 8 - 51% 23%
Aoudad 2 - 50% 20%
Cow 0 - 73% 15%
Table 2 Spring and Summer Browse Seasonal Variation in Nutritional Value
Plant Crude Protein Energy Value Month
Algerita 16% Very high March
Algerita 8% Very low May
Bumelia 25% Medium March
Bumelia 14% Low July
Elbow bush 21% High March
Elbow bush 7% High October
Flameleaf sumac 23% High April
Flameleaf sumac 11% Low July
Greenbriar 28% Very high April
Hackberry 25% Very high April
Hackberry 8% Low July
Kidneywood 24% Medium April
Kidneywood 17% Medium October
Live oak 12% Medium May
Live oak 10% Very low September
Mesquite 32% High April
Mesquite 16% Very low June
Old man's beard 22% Medium April
Old man's beard 15% Medium July
Persimmon 25% High April
Persimmon 10% Low July
Pricklyash 18% Very high May
Pricklyash 15% Very high October
Pricklypear 7% Very high July
Roemer acacia 20% Very high April
Roemer acacia 13% Medium September
Shin oak 15% High April
Shin oak 11% Low October
Skunkbush sumac 14% Very high March
Skunkbush sumac 11% Very high May
Table 3 Evergreen Winter Browse Nutritional Value in Midwinter
Plant Crude Protein Energy Value
Cedar 7% Medium
Ephedra 12% Very low
Evergreen sumac 7% Low
Greenbriar 10% Low
Live oak 9% Very low
Mistletoe 17% Medium
Pricklypear 6% High
Silktassell 6% Low
Tasajillo 8% High
Table 4 Relative Preference of Common Hill Country Browse Plants
Class 1 Class II Class III Class IV
Highly Preferred Preferred Non-Preferred Least Preferred
Black willow Black cherry Button bush Algerita
Carolina buckthorn Blackjack oak Evergreen sumac Catclaw mimosa
Elms Bumelia Feather dalea Cedar
Hawthorne Carolina snailseed Flameleaf sumac Cenizo
Kidneywood Dewberry Hogplum Condalia
Littleleaf leadtree Elbowbush Lacy oak Fragrant mimosa
Madrone Ephedra Littleleaf sumac Lotebush
Maple Grapevine Live oak Mesquite
Mistletoe Greenbriar Peachbrush Mexican buckeye
Mountain mahogany Hackberry Pecan Mountain laurel
Possumhaw Huisache Poison ivy Persimmon
Rusty blackhaw Old mans's beard Post oak Pricklyash
Shrubby boneset Redbud Shin oaks Pricklypear
Snowbells Roemer acacia Silktassel Tasajillo
Spanish oak Roughleaf dogwood Skunkbush sumac Wafer ash
Texas mulberry Virginia creeper Sycamore Whitebrush
Texas sophora Western soapberry Walnut Willow baccharis
White honeysuckle Wild plum
Table 5 Top Ten Browse Plants of the Hill Country