RANGELANDS14(2), April 1992 77 fXOTICS —At Home on the Range in Texas Steve Nelle Man has always had the compell- andWildlife Department survey (Tra- livestocksuch as cattle, sheep, and ing desire to "improve" nature. Eu- week 1989). goats, which are no less exotic in ropean man (himself an exotic in These animals range in size from origin. Neitherare feral hogsincluded North America) eliminated the prim- the 75-pound blackbuck antelope for which no reliablepopulation esti- ary nativegrazing animal (bison)and that eats about three pounds of for- mates exist. it with cattle. In to the 1,500- replaced European age per day (dry weight) More Exotics many areas, the native bluestem poundeland that consumes about30 Why prairies have been overgrazed and pounds per day. Moretypical are the In the early daysof exotic wildlife replaced withexotic "improved" blue- 150-pound axis deer and the 350- introductions,they represented little stems. Man, especially in the last more than an interesting curiosity. century,seems to derive great satis- During the period of the 1960's and faction in reshuffling the plant and 1970's, fee huntingof exotic big game animal communitiesof the world. became a motivation. The economic With seven species of nativeungu- incentive for raisingexotics in recent lates (hoofed mammals), and three years has evolved into acorn bination major kinds of domestic livestock, of hunting, meat production, sale of landowners in Texas have now intro- brood animals, and some non-con- duced 68 other species of exotic sumptive uses suchas photo safaris. ungulates into the rangeland ecosys- Withthe exception ofauodad sheep tems of the state. Interestingly, three in the Palo Duro Canyon,exotics are of the seven indigenous species no not considered game animals in longerhave viable native populations. Texas, and are not subject to state The increasing numberof exotic un- regulated seasons and bag limits. gulates, dependent upon the range Hunting can occur throughout the resources ofTexas demand the appli- year. Trophy hunting fees generally cation of innovative range manage- rangefrom $800 to$1 ,200 for mature ment techniques. horned or antlered males ofthe com- mon species. History and Recent Trends Ranchers may also sell surplus The introduction of wild exotic animals for meat, and receive $1.00 herbivoreson Texas rangeland began to $2.25 per pound dressed carcass in about 1930when ranchers released weight, depending on the species nilgai antelope in south Texas. By and theefficiency ofharvest by shoot- 1932, four more species of deer or ing. This translates to $0.50 to $1.24 antelope were introduced. During per pound live weight. The killing the 1950's, four morespecies of deer and processing of meat animals for and sheep were released. By thetime Fallow deer, a commonran geland exotic, sale is subject to USDA inspection of the first statewideexotic survey in are alsobeing "farmed" for meatproduction requirements. Retail prices to the 1963, there were 13 species totaling in New York and Texas. consumerrange from $4.00 to over about 13,000animals on 178 ranches $7.00 per pound. Meat from exotic (Ramsey 1969). Twenty-five years pound nilgai antelope. Of these 68 deerand antelopeis low in fat, cho- later in 1988,68 species and 164,000 species, six comprise 87%of the total lesterol and calories. In addition, these animals were present on about 468 number. These six species are: axis animals generally subsist on a diet ranches, accordingto a Texas Parks deer; nilgai antelope; blackbuck ante- freefom medicationand growth stimu- lope; auodad sheep; fallow deer; and lants. With the trend toward more Author is biologist, Soil ConservationService, San Angelo,Texas. sika deer. Not includedare domestic healthy diets, this segment of the 78 RANGELANDS 14(2), April 1992 cially in the central part of Texas, there are no unfilled niches with regard to plant utilization. If an exotic species were found that preferred to feed on mesquite, juniper, algerita, creosote bush or othersuch invasive plants, then there might be a legitimate ecologicalneed to stock suchanimals. A long history of multi-species grazing involving cattle, sheep, goats andwhitetail deer has left no surplus of any desirable kinds of forageon many ranches. In too manycases, it is on these already depleted ranges where many exotics are being raised. In attempts to justify heavy stock- ing ofexotics, it has been pointedout The distribution of exotics in Texas. Each dot represents 100 animals. exotic industry appears destined to forageconsumption with foragesup- grow. ply. This balance mandates that the Even though an economicmotiva- long-term health of the plant com- tion existsfor raising and marketing munity be maintained or improved. exotics, there also exists a strong Realizing that different animals have aestheticmotivation to having exot- different feeding habits, proponents ics. A 1988survey revealed that about ofthe exotic industrypoint outthat it 42% of landowners with exotics did makesgood ecological and economic not allowthem to be harvested either sense to fi'l unoccupied niches. For for trophy or meat. example, if the browse resourceon a given range was being under util- Confined or Escaped ized, it may be prudent to introduce With the economic investment in- the proper number of browsing volved in purchasing exotics, most animals into the system. The prob- landowners intend to keep their lem is that on many ranches, espe- animalson their property. Although some species are containedby trad tional net-wirelivestock fences, most There are over 12,000 sika deerin Texas. exotics requirea high fence for con- finement. Despite the best efforts at that some operationsrely heavily on maintaining fences, many escapes supplemental feeding, therebyreduc- haveoccurred, and asof 1968,almost ing impactsto therange. Experienced 74,000 exotic animals or 45% of the observers have noted that like live- statewidetotal are now free-ranging tock, exotics have the foraging in- animals (Traweek 1989). stinct to utilize naturalvegetation in The traditional ecological fears of preference to feeds. When exotics escaped exoticsare a legitimate con- are making heavyuse ofsupplemen- cern in Texas. The New Zealand tal feeds, the range already experienceof severe resource dete- shows excessive use. riorationcaused by exotic deerover- Even when the kinds and numbers populations is well known. Several of animals are balanced to the carry- authorities in Texas have conceded ing capacity of the range, there is that the free-ranging population of another problem with exotics. With exotics are nearly impossible to yearlongcontinuous grazing, the se- control. lective feeding habits of herbivores generally lead to overutilization of Range ManagementConcerns preferred species. Grazing systems can overcome this when One of the primary concerns in Large numbersof auodad sheep are free- problem rangemanagement is the balance of ranging in the mountainsof west Texas. properlyexecuted. However,very few RANGELANDS14(2), April1992 79 Multiple species of exotics oftenexist with native whitetail deer. Mature axis buckin center. exotic ranches are set up to allow stated that diet overlap does not It mustalso benoted that intraspe- such herd management. In most necessarily mean competition. Com- cific competition among over- cases, exotic populationsconsist of petition onlyexists whenthe resource abundant whitetail deer is often wild animals not easily moved like is limited and there is greatdemand severe. In many cases, this deer to livestock from pasture to pasture. for it. The implication is that consid- deercompetition is morecritical than The expense of building suitable in- erablediet overlap can occurwithout interspecific competition between terior,cross-fencing toaccommodate competition or resource deteriora- deer, livestock and exotics. Manage- grazing systems is noteasily justified tion. While this may be theoretically ment of excessive native deer popu- in the eyesof most exotic ranchers. true, in the real world diet overlap lations should be no less a resource The current cost of high fencing is between species most often results concernthan management of exotic about $10,000 per mile. in competition and resource abuse. livestock and wildlife. Wildlife ManagementConcerns One of the most often voiced con- cerns about exotic wildlife in Texas is their impacts upon native wildlife and wildlife habitat. Much of the concernrevolves around forage com- petition with native deer, both white- tail and mule deer. Other legitimate concerns include the impact upon herbaceous and woody cover for deer, turkey, quail, numerous non- game species, and the endangered black-capped vireo. The degree to whichvarious exotic wildlife species compete with native wildlife has been debated and re- Badly deterioratedran geland in central Texas, subjected to long years ofabusive man- searched. Certain researchers have agement with exotics, livestock and whitetail deer. 80 RANGELANDS 14(2), April 1992 Conclusions Exotic wildlife consume a signifi- cant and expanding portion of the total forage on some Texas range- lands. When their numbers are not managed, they have the same detri- mental effects on rangeland as any other herbivore. Research, surveys, andfield observation have presented the following considerations: 1. The productsprovided by exot- ics (aesthetic pleasure, recreation, and lean red meat) are important to consumers. Compare the vigor and productivity of orange zexmenia, a common forb from we// managedran geland