Proper Use Of Grazing And Fire
Help Endangered Species Thrive

By Colleen Schreiber

(Editor’s note: This article is especially timely as it relates to techniques for dealing successfully — and rationally — with officially "endangered" birds who got that way as a result of parasitism by brown-headed cowbirds. Eco-activists and federal land managers in Arizona and New Mexico have recently announced a much less intelligent method of addressing the problem — simply banning cattle. The Kerr area’s information is available, its success is documented, and whether or not the activists and bureaucrats choose to embrace it will be proof positive of their real intentions toward "endangered" species: whether they actually want to protect them, as they claim, or use them as an excuse to drive livestock off the land, as the ranching community believes. The choice is crystal clear, and the ball is in their court.)

ABILENE — The Kerr Wildlife Management Area must be doing something right. Its success story centers around traditional ranching practices like the grazing of domestic livestock, and various brush control practices including prescribed fire. Kerr area personnel have demonstrated that used properly, those management tools can enhance the habitat for certain endangered plants and animals.

Bill Armstrong, a wildlife biologist at the Kerr area, outlined the program at the recent Texas Section Society for Range Management annual meeting here.

"We’re increasing two endangered birds and one endangered plant," Armstrong told listeners. "We don’t intentionally manage for those endangered species. The reason we have them is that we put a process in place that kind of mimicked the oldtime system."

"This country evolved under a system for several thousand years," Armstrong explained, "and this system was built on disturbance, two of those disturbances being fire and buffalo."

Fire, Armstrong noted, was part of the landscape for a very long time. In some areas it was frequent and in other areas not very frequent; some areas didn’t burn at all. Because of that, the Texas hill country was a mosaic of different species that evolved to fill a variety of niches.

The Kerr area has spent the last several decades trying to mimic those influences, and the tools they use today are short duration grazing and fire. Additionally, Armstrong said, hunting and trapping can be used in place of predation to maintain animal numbers in proper balance.

"These relationships, plant to plant, animal to plant, animal to animal developed over many years," Armstrong said. "If we are going to make our lands healthy again, we need to begin to understand those processes. We know some of the processes, but we don’t know a lot about the whole system."

The Kerr area is home to the officially "endangered" black-capped vireo, golden cheeked warbler and the fishook cactus.

The black-capped vireo went on the federal endangered list in 1986. At one time it was found in Kansas, Oklahoma and Texas. Its last major stronghold is in the Edwards Plateau of Texas.

The bird is only three inches long and it likes to build a "hanging cup" type nest three feet off the ground in clumpy vegetation, Armstrong said. It lays four eggs to a nest and has an incubation period that is about two days longer than that of most other birds.

The problem in the Edwards Plateau, he told listeners, is that there are a lot of cows, sheep, goats, whitetail deer, black buck antelope, aoudad, mouflon, axis and sika deer.

"We have browse lines out there," he explained. "If you like to build your nest about three feet off the ground, you’ve got a problem."

Another problem is the brown-headed cowbird. Prior to the arrival of domestic livestock, the cowbirds followed the roaming buffalo herds. Because the buffalo were constantly on the move, the birds didn’t have time to build a nest or raise their young, so they developed a habit of putting their eggs in other birds’ nests.

Scientists say that cowbird has increased by the billions since 1900, Armstrong noted.

"We wiped out the buffalo, went to continuous type grazing with cattle and fences, and the cowbird didn’t have to fly around very much. They have increased tremendously," he said. Today the cowbird is impacting about 200 species of birds, and it particularly "likes to pick on little birds with hanging type nests."

Because of the vireo’s slightly longer incubation period, the baby cowbirds hatch first, the vireo mother quits incubating the nest, starts feeding the baby cowbirds, and in the end doesn’t raise its own young. About 95 percent of black-capped vireo nests are really raising cowbirds, Armstrong said.

"If you do this for 80 to 90 years, you tend to get put on the endangered species list."

When the bird went on the list, some people said the only way to bring them back was to remove cattle from vireo habitat because cattle attract cowbirds.

But that’s not what the Kerr management area did. To deal with nest parasitism, the management area is trapping cowbirds using traps baited with other cowbirds. Originally, the traps were put where the black-capped vireos’ nests were and cattle were rotated away from the nesting areas.

Nest parasitism went from 80 percent down to around 60 percent. When they had the cattle in the nesting area, however, they trapped even more cowbirds, so personnel began moving the cowbird traps with the cattle as they rotated through the grazing system.

Today nest parasitism is down to about nine percent and black-capped vireo numbers have grown tremendously. The biologists’ last survey showed that about 220 birds nest on the management area, up from an initial count of only 26 birds.

Research indicates that 15,000 to 20,000 years ago the area was probably a spruce forest. Then about 10,000 years ago the climate began to change and the vegetation went from spruce forest to brushland. By the time of European settlement the land was basically a grassland.

Beginning in about 1840, settlers brought cows, horses, sheep and goats, and began grazing the county at a heavy rate. The early settlers also controlled the naturally occurring fires that had helped maintain the grassland with its scattered canopy of low trees.

As a result, sometime around the turn of the century the area began to change back to predominantly woody vegetation, and by 1940 or 1950 the woody plants had given way to cedar.

When the Texas Parks and Wildlife Department purchased the Kerr area to study whitetail deer, it was basically a solid cedar brake.

The biologists on the management area initiated several food habit studies which showed that the majority of the wildlife and livestock, with the exception of cattle, were primarily browse and forb eaters but all could easily switch to grass. The problem was that none of them ate cedar.

"That’s why we went from this grassland to a brushland to by the 1940s mostly a cedar brake. By the 1940s, most of the plants that were left on the land were those plants that the animals didn’t like to eat," Armstrong remarked.

Based on that information, beginning in 1964 TP&W began removing and piling the cedar. At that time department policy held that fire was a bad thing, so all that cedar was left in piles to rot.

"We had 15 acres out of every 100 acres in some type of cedar pile," Armstrong recalled.

By 1972 the cedar had grown back and it was hand cut at a cost of about $6 to $8 an acre. By 1979 they were facing the same scenario again, but this time it was going to cost about $30 an acre to hand cut it.

That figure and the fact that trained wildlife biologists had better things to do with their time than hand cut cedar, finally gave the agency the impetus to change its policy on prescribed burning.

Armstrong and his colleagues had been experimenting with fire off the area for several years and had come up with a technique to kill the cedar and not harm overstory plants.

In 1979, the biologists began a program to burn 20 percent of the management area each year. That meant that every five years a pasture on the 5000 acre management area would be reburned.

Prescribed fire has proven beneficial in several aspects, Armstrong said, including promoting a greater variety of plants on burned areas versus unburned areas.

More important to some, fire has proven to be a beneficial management tool for the perpetuation of the vireo. Many browse species are prolific sprouters, Armstrong explained, and burning not only helps reduce the stature of the brush canopy but it also encourages resprouting.

"It’s that low-growing, clumpy vegetation," he reiterated, "that these endangered birds prefer."

At about the time that the Kerr area began to address the brush encroachment problem, scientists also initiated research on two grazing systems, the Merrill four-pasture, three-herd system and a three-pasture, one-herd version.

In 1968 a deer proof fence was built around the management area. It was built, Armstrong says, not to keep deer in, but to keep excess deer out. At its peak, he said, the Kerr area was harvesting 432 deer on 5000 acres.

They continued to put pressure on their whitetail deer herd to get numbers in proper balance. Additionally, goats were removed from the system in the 1960s and sheep in 1977, but cattle remained. As these various changes were implemented, deer quality improved and it continues to improve.

Research showed that they were growing better deer in the three-pasture system than in the four pasture version, so they switched exclusively to the three-pasture system, Armstrong said.

They also began to study a modified high intensity low frequency system, grazing seven pastures for 30 to 35 days and making about 2.5 cycles in a year’s time. Deer began to move from the three-pasture system to the HILF system. Next they got rid of the HILF system and started a short duration system with 33 pastures and one herd of cattle grazing three to five days per pasture.

By 1989 the Kerr area was producing 140-pound field dressed whitetail deer. By 1992 weights had jumped to 241 pounds and by 1994 they had deer scoring 168 Boone and Crockett points. Today their deer have a 120-pound average field dressed weight, up from 79 pounds when they started.

Other notable improvements included moving from an average of 430 pounds to 550-plus on weaned calves, from a 50 percent fawn crop up to 100 percent, and a marked improvement in species composition of grass and forbs as well as the better browse species, from 60 different kinds of plants to 90 or so.

Today, managers of the Kerr area leave strips of cedar which serve as deer cover. They’ve also left a "relic" site, a 480-acre block of oldgrowth cedar as nesting habitat for the golden-cheeked warbler.

In 1984, the management area had about 18 warblers. Today they have a minimum of 30 birds and Armstrong said the actual count would probably be closer to 50 birds.

The first endangered Tobusch fishhook cactus was found on the management area in 1989. Last year they found some 30 plants growing in pastures that had been burned and grazed by livestock.

"When I was a young biologist, people would ask how to control prickly pear or mesquite, and I would tell them to buy chemical ‘x,’ spray it and the problem will go away. That was a wrong answer," Armstrong said. "The reason it was a wrong answer was because I got the wrong question. The question should have been ‘why do I have that mesquite or prickly pear?’ and maybe that would force me to give a better answer.

"We need to manage for a system and understand how those old systems worked," he continued, "and if we do that then I think we’ll have a good future for both livestock and the wildlife."

Unfortunately, not enough of the right people are hearing these kinds of success stories. Referring to the federal endangered species act, Armstrong said, "We lost that battle back in the 1970s when the environmental groups got into the classrooms with their coloring books and other literature."

Armstrong said he is of the opinion that the Texas Section Society for Range Management, land managers, ranchers and farmers alike — anyone who has an interest in keeping private lands in private hands — must find a way to get its message into the classrooms of America.

"It’s going to be a long haul, but somehow we have to mainstream our message into the schools and teach the teachers who are teaching."