Spotlight Habitat Management Practice: The Value of Bare Ground

By: Evan McCoy, Senior Wildlife Biologist

Many people think of optimal wildlife habitat as a continuous, thick layer of vegetation across the landscape. With the amount of rainfall that much of the Hill Country has received over the last two years, we saw a tremendous growth of plants that resulted in just this scenario.  Some may see the amount of ground cover being directly proportional to good wildlife habitat. Producing plants is certainly a focus in most wildlife management plans so it is understandable that people are pleased by such an abundance of it. Many landowners express concern about isolated sites where plant growth appears sparse or nearly non-existent, and they usually want to know how they can fix it. This concern may stem from negative impacts of prolonged drought or overgrazing. While an excess of bare ground is frequently associated with poor range health, there are benefits that bare ground can provide for wildlife.

Bare ground can improve habitat diversity by allowing the growth of early successional, or pioneer, plant species that may not be present otherwise. This is typically forbs, or wildflowers, which are an important food for a variety of wildlife, and often limited due to heavy grass and brush cover. Exposing some soil also increases mobility for numerous small wildlife species such as reptiles and ground dwelling birds. Imagine something the size of a quail or a lizard and then determine if that animal would be able to effortlessly travel through the pasture. These open sites are also where these animals can access and forage on seeds and insects.  

So, how much of nothing should one have? There should be a balance between vegetative cover and bare ground. The ideal ratio is strongly determined by the targeted wildlife species. Most of the landscape should meet an animal’s cover needs but contain an interspersion of bare soil. In most cases, these areas should not be completely void of vegetation but instead should be an area of exposed soil that is thinly covered with grasses and forbs.

There are a few common methods to create more open space. Light disking, where applicable, is a great way to selectively break up thick layers of grass and expose areas of bare soil. Occasional mowing or shredding, though lacking the soil disturbance benefit, can produce a similar effect. These treated strips can promote forbs, like croton and ragweed, which may improve wildlife mobility and provides a good seed source. Prescribed fire will reduce that thick accumulation of grasses that can dominate the range, and burning also limits brush growth and encroachment. A proper cattle grazing system is arguably the best practice for thinning vegetation due to both the grazing and hoof action it provides. If done properly, the result will be a mosaic of both moderate to light grazing sites throughout the ranch.

To manage for a diversity of wildlife, it is important to provide diversity on the rangeland. It may look nice to see a continuous layer of grass on your property, but animals need some variety in plant structure, composition and abundance. Applying the proper management can ensure that your property can be utilized by a wider range of wildlife.

Quail Roadside Surveys

By: Austin Stolte, Wildlife Biologist - Val Verde County

The Edwards Plateau is home to three species of quail: the bobwhite quail, which is found through most of the Hill Country, the scaled quail which is found in the western Hill Country, and the Montezuma which is found in specific habitat in Edwards, Real, and Val Verde Counties. Quail abundance in the Hill Country is quite variable depending predominantly on habitat quality preferred by each species of bird. Numbers fluctuate greatly from year to year and are largely driven by rainfall. To monitor these populations each year TPWD staff conduct quail roadside surveys in early August. For the roadside surveys, TPWD biologists focus mostly on bobwhite and scaled quail range. Although we love that Montezuma quail call the Hill Country home, their population is very low and because of their reclusive nature can be very difficult to survey. The roadside surveys are scattered across the region mostly on lesser traveled Farm to Market and county roads. Each established route is 20 miles in length and is driven slowly either at sunrise or sunset and birds are documented. Population metrics are recorded including covey size, age class, and sex. This data is then used by the Upland Game Bird Program to track eco-region population trends, chick recruitment, and predict seasonal hunting outlooks. It is important to note that this data collection method looks at quail population trends at an ecological scale and they are not a good predictor of quail population on a specific ranch. For those ranches wanting to learn more about localized quail numbers or quail management, you should contact your local biologist.

From the WMA: Texas Horned Lizard Research

By: Kirby Irvin, Coryell & Eastern Lampasas Counties

Texas is diverse in its landscapes and wildlife, and many species call this great state home. Arguably one of the most notable is the horny toad, formally known as the Texas Horned Lizard (Phrynosoma cornutum). Recognized by its fierce-looking horns and flat camouflaged body, the horny toad was once common across the arid and semiarid habitats of the south-central United States and Northern Mexico.

However, in 1977 the Texas Horned Lizard was listed as a threatened species in Texas as a result of major declines in their populations from habitat loss, urbanization, and the spread of fire ants. To better understand this decline and develop management strategies for the future, researchers and biologists teamed up to try and find solutions.

Beginning in 2015 at Mason Mountain Wildlife Management Area, the Texas Horned Lizard project started looking at ways to successfully restore horny toad populations. In the first two years 41 adult Texas Horned Lizards were released, each equipped with a backpack transmitter for monitoring purposes. Unfortunately, few lizards survived with the conclusion that translocating as adults was not a viable option.

With adult releases unsuccessful, the next possibility was to look at releasing hatchlings. Since 2017, thanks to cooperation from multiple partners, over 1,674 horny toad hatchlings have been released at Mason Mountain. Very few hatchlings have reached adulthood, as predation and competition from fire ants still pose challenges. Research is still ongoing looking at the efficacy of releasing hatchlings, as the solution to population restoration on a large scale has not yet been found.

Spotlight Animal: Spot-tailed Earless Lizard

By: Mike Miller, District 5 Leader

Since the turn of the twentieth century Texas has been in a state of change.  Wildlife species that adapt to changing environmental conditions and land management practices tend to persist.  The Plateau spot-tailed earless lizard (STEL) Holbrookia lacerata can stake its claim among the resilient.  This small, ground-dwelling lizard is endemic to Central Texas semi-desert grasslands and occupies an area roughly the size of its historical range between the Balcones Escarpment and the Colorado River.  

STEL are slightly flattened in appearance, have no external ears and have a series of dark spots found dorsally, along the underside of the tail and sometimes, between the legs.  Adults are 4.5 to 6 inches from snout to tip of tail, with the tail making up about one-half of total length.  Sexes and ages have a similar appearance except for gravid females that often have a light green appearance on the neck and back just before depositing eggs in the spring and summer.  External egg incubation requires 4-5 weeks, and hatchlings are about 1.5 inches long, including the tail.

The lizards prefer open grassland habitats that are frequently disturbed by grazing and fire and are less likely to be found in dense brush and tree cover.  STEL are diurnal and frequent bare soil areas where they bask on warm, sunny days to increase their internal body temperature.  They spend most of their time underground, self-burying under loose soil or utilizing crevices and burrows for shelter.  They are dietary generalists and sit-and-wait predators that prefer to eat grasshoppers and spiders while occasionally consuming beetles, ants and termites.

Its close relative, the Tamaulipan spot-tailed earless lizard (H. subcaudalis), resides in south Texas and northern Mexico and remains under consideration for federal protection under the Endangered Species Act.