Current Status, Distribution, and Conservation of the Burrowing Owl in Oki,Ahoma

j Raptorl•,s. 35(4):351-356 ¸ 2001 The Raptor Research Foundation, Inc.

CURRENT STATUS, DISTRIBUTION, AND CONSERVATION OF THE BURROWING OWL IN OKI,AHOMA

STEVEN R. SHEFFIELD 1 U.S.Fish and WildliJkService, 4401 N. Fairj'•txDrive, Suite634, Arlington,VA 2220_3U.S.A. and Departmentof Biology,George Mason University,P•tirj•tx, VA 22030 U.S.A.

MARK HOWERY NongameDepartment, Oklahoma Dq•artment of WildliJkConservation, 1801 N. Lincoln, OklahomaCity, OK 73152 U.S.A.

Agsrg•CT.--In Oklahoma, the Burrowing Owl (Athene6•nicularia) historicallyinhabited much of the westernhalf of the state.Over the last century,habitat destructionand alteration, including destruction of prairie dog (Cyn0mysspp.) colonies,have taken a toll on the remaining Burrowing Owls in Oklahoma. Currently, owls occupy only a relatively small portion of their historical range in the state. A recent surveyindicated that total colonyarea in the statecontinues to decline,decreasing 4-7% over the past 10 yr. As prairie dogs continue to be eradicatedby humans and impacted by plague over significant areasof Oklahoma, it is not surprisingthat Burrowing Owls continue to decline. Currently, there are an estimated800-1000 Burrowing Owls breeding in Oklahoma, and most of these occur in the three panhandle counties (Cimarron, Texas, and Beaver). Breeding Bird Survey data showedthat the Bur- rowingOwl populationhas significantlydeclined (12.3%/yr) in the state.Christmas Bird Count data, although limited, also suggestdecreasing numbers of wintering Burrowing Owls in the state. These findings are a causeof great concern for the Burrowing Owl in Oklahoma. Major cooperativeefforts are needed to ensure that viable populations of Burrowing Owls continue to exist throughout the species'range in Oklahoma. KF•¾WORDS: BurrowingOwl; Athene cunicularia; status;distribution; conservation; black-tailed prairie dtcff, Cynomysludovicianus; Oklahoma.

Estado actual, distribuci6n, y conservaci6ndel Bfiho Cavador en Oklahoma RESUMEN.•EnOklahoma, el Bfiho Cavador(Athene cunicularia) hist6ricmnente ha habitadola mayorparte del lado oeste del estado.En el ulfimo siglo, la destrucci6ndel hfibitat y su alteraci6n, incluyendola destrucci6nde las coloniasde perrosde la pradera (Cyn0mysspp.) ha tomadoun numero de bajasen los restantesBfihos Cavadoresde Oklahoma. Actuahnente los bfihos ocupan solamenteuna porci6n relati- vmnentepequefia de su rango hist6ricoen el estado.Un estudioreciente indic6 que el/trea total de las coloniasde los perros de la pradera continuadisminuyendo abruptamente, decreciendo 4-7% en los filtimos 10 aftos.Como los perros de las praderasestrin siendo erradicadospot los humanosy devastados pot la peste sobre fireassignificativas de Oklahoma, no es sorprendenteque el numero de Bfihos Cava- dotes continfie decayendo.En la actualidad,hay un estimadode 800-1000 Bfihos Cavadoresreprodu- ci6ndoseen Oklahoma, y la mayorla de estasocurren en los tres condadosde la regi6n "manija" (Ci- matron, Texas,y Beaver). Los datosdel Estudiode Avesen Reproducci6nmuestran que las poblaciones de bfiho cavadorhah decrecidosignificativamentc (12.3%/afio) en el estado.La continuaci6nde estas tendenciasresultar/t probablemente en la necesidadde protecci6nlegal bajo la ley estatalde especiesen peligro.Se necesitanesfherzos cooperativos mas grandes para asegurarque poblacionesviables de Bfihos Cavadoresconfinfien exisfiendoa lo largo y ancho de su rango en Oklahoma. [Traducci6nde Victor Vanegasy C6sarM/trquez]

Historically, the Burrowing Owl (Athenecunicu- (Baumgartner and Baumgartner 1992, Haug et al. laria) inhabited the western one-half of Oklahoma 1993). Prior to settlement of the Oklahoma Terri- tory in the 1880s, Butt owing Owls were locally common summer residentsin grasslandsof central E-mail address:[email protected] and western Oklahoma, but they were largely ex-

351 352 STATUSAND TRENDS VOL. 35, No. 4 tirpated by 1930 (Baumgartner and Baumgartner Burrowing Owls (Tyler 1968, Buttsand Lewis 1982, 1992). They were commonly found in shortgrass J. Shackford,J. Tyler, and L. Choateunpubl. data). prairie habitats and were closely associatedwith SUMMER RECORDS black-tailed prairie dogs (Cynomysludovicianus). Currently, they are a rare and local summer resi- The current summer (breeding) range of the dent, mainly in the Oklahoma panhandle and oth- Burrowing Owl in Oklahoma was derived from er western counties (Baumgartnerand Baumgart- BBS data (1966-99), other breeding records, and net 1992). Modern development and agriculture personal observations. Burrowing Owl family have resulted in large-scaledestruction and alter- groupshave been docmnentedduring the summer ation of Burrowing Owl habitat in Oklahoma and months in the prairie dog colonies of 13 western other Great Plains states. In addition, sylvatic counties (Fig. 1). It is likely that Burrowing Owls plague (Yersiniapestis), shooting, and poisoning also nest in or around severalprairie dog colonies have greatly reduced prairie dog populations, re- in Cotton and Custer counties, but there are no sulting in population numbers that are only a frac- confirmed records or sightings.Based on Tyler's tion of what they were historically.Burrowing Owls (1968) data and our subjective assessmentof todayoccupy only a relativelysmall portion of their changes since that survey,we estimated that there historical range in Oklahoma, and numbers are is a current summer population of 800-1000 Bur- greatlyreduced from historicalestimates. The larg- rowing Owls in Oklahoma, with most owls occur- est populations are found in Cimarron County in ring in the three panhandle counties (Cimarron, the panhandle (Baumgartner and Baumgartner Texas, and Beaver; Fig. 1). 1992). Currently, the Burrowing Owl is classifiedas Tyler (1968) surveyed black-tailed prairie dog a Species of Special Concern in Oklahoma colonies in Oklahoma, recording a total of 788 (Oklahoma Department of Wildlife Conservation Burrowing Owls, and derived a statepopulation es- publ. comm.). It is also a Speciesof Special Con- timate of 900-1000 individuals. In his survey in cern in the neighboring stateof Kansas,but has no 1970, Butts (1971) found a total of 543 Burrowing Owls, and estimatedan overall densityof nesting official listing in either Texasor New Mexico (Shef- Burrowing Owls of approximately0.12 owls/km2 field 1997a). The black-tailedprairie dog, a species He also found that 66% of the nests occurred in that is ecologicallylinked to the Burrowing Owl in black-tailed prairie dog colonies, although those the Great Plains, is also classifiedas a Speciesof coloniesmade up <20% of the total landscapesur- SpecialConcern in Oklahoma (Oklahoma Depart- veyed. Burrowing Owl densitiesvaried greatly be- ment of Wildlife Conservationpubl. comm.). tween thoseowls occupying black-tailed prairie dog To date, there has been no systematicsurvey of colonies (38.1 owls/kin 2) and those at least 1.6 km Burrowing Owls in Oklahoma. In the summer of from black-tailed prairie dog colonies (0.04 owls/ 1970, Butts (1971) studiedthe ecologyof Burrow- km2). All Burrowing Owl nestswere found in veg- ing Owls in Beaver and eastern Texas counties. etation that was <10 cm in height (Butts 1971). This is the most complete estimate of population According to the Oklahoma Breeding Bird Atlas densityof Burrowing Owls in Oklahoma, and there (OBBA) conducted through the 2001 field season, has not been a similar survey since. In 1970, the Burrowing Owls were recorded in 32 of the 42 total area covered by prairie dog colonies in OBBA blocks (1.86 X 2.17 km) surveyedin the Oklahoma was less than half of the area it was it• Oklahoma panhandle that also had at least one 1960 (Butts 1971). BurrowingOwl populationsare prairie dog colony (D. Reinking pets. comm.). small or nonexistent in areas of central and west- This included 9 of 11 blockstbr BeaverCounty, 11 ern Oklahoma where prairie dogshave been erad- of 16 for Texas County, and 12 of 15 tbr Cimarron icated (Buttsand Lewis1982). The Oklahomapan- County. In addition to the above, nesting records handle is still largely undeveloped, and is exist for Grant, Cleveland, Oklahoma, Canadian, characterized mainly by cattle ranching, agricul- Custer, Blaine, Woods, and Alfalika counties. The ture, and open prairie. In this area, prairie dog latter records,however, ranged in date from 1909- coloniesare still relativelylarge and numerous.As 65, and it is not clear how many of these represent you move east from the panhandle, development annual nestingattempts by establishedpopulations is more prevalent, prairie dog coloniesare lessfre- opposed to accidental or occasional nesting at- quent and more fragmented, and there are fewer tempts. Baumgartner and Baumgartner (1992) in- DECEMBER 2001 Bt RROWING OWl S IN OKI.•.HOMA 353

I..ClMARRON TEXAS BEA1/ER

Figure 1. Breeding range (shown in gray) of the Burrowing Owl in Oklahoma, as determined by Breeding Bird Surveydata (1966-99), other breedingrecords, and personalobservations. Gray areasdenote regularbreeding range

dicated that the Burrowing Owl was not a regular 1976). The winter can be relativelysevere in north- breeding speciesin central Oklahoma prior to Eu- ern Oklahoma, and Burrowing Owls facing these ropean settlement. conditions generally migrate south for the winter. Breeding Bird Survey (BBS) data indicate that In the southwestern counties of Oklahoma, owls Burrowing Owls occur in many of the westerncoun- are considered occasional winter residents (Baum- ties in Oklahoma (Sauer et al. 2000). The BBS data gartner and Baumgartner 1992). The survey by indicate that relative abundanceof Burrowing Owls Butts (1976) alloweda comparisonof summerand is low (range 0.13-1.95) for all four physiographic winter Burrowing Owl numbers. He surveyed an regionsof the state.Analysis of these data demon- area of 4367 km2 in the eastern panhandle and strate that Burrowing Owl numbers in Oklahoma found 543 adult owlsduring the 1970 breeding sea- declinedby 12.3% per yr during the 34-yr period son and 527 adult owlsduring the 1971 breeding from 1966-99. BBS data quality for BurrowingOwls, season. However, he located only six owls in the although less than optimal due to the relatively same area during the 1970-71 winter (ca. 1% of small number of BBS routes in the state, is none- the summer population). theless the most useful data available for determin- Burrowing Owls have been recorded on CBCs at ing population trends of this speciesin Oklahoma. Kenton (Black Mesa), Cimarron County, Arnett (Ellis County), Oklahoma City, Oklahoma County, WINrFERING RECOROS and Norman (Cleveland County). There have nev- The current wintering range of the Burrowing er been more than a few individuals reported from Owl is restricted to western Oklahoma (Fig. 2), any count. In addition to winter records in the based on Christmas Bird Count (CBC) data, other western counties, there are winter records of Bur- wintering records, and personal observations rowing Owls for a number of scattered counties in (1930-99). Most Burrowing Owls migrate south other areas of Oklahoma, including Oklahoma, from Oklahoma in the fall (usually October) and Muskogee, Garvin, Tulsa, Pawnee, Payne, and some winter as far south as central Mexico (Butts Washington counties (Baumgartner and Baum- 1976, G. Holroyd pets. comm.). Therefore, Bur- gartner 1992, Sauer et al. 1996). The winter distri- rowing Owls are considered either rare winter res- bution of Burrowing Owls is broader than their idents or are very secretive in the panhandle and breeding distribution in Oklahoma (Figs. 1, 2) and the northern tier of counties in Oklahoma (Butts may be due, at least in part, to stopoverof migrants 354 STATUSA•D TPm•DS VOL. 35, NO. 4

C•ARRON

Figure 2. Non-breeding range of the Burrowing Owl in Oklahoma, as determined by Chrislmas Bird Count data (1930-99), other wintering records, and personal observations.Dark gray area denotes regular winter range, light gray areas denote extra-limital winter records. from more northern parts of the range. A similar ODWC game wardensconducted a follow-upsurvey pattern of winter distribution in Texas and Mexico in the fall of 1998. Of the 399 prairie dog colonies offers some evidence for this idea (G. Holroyd recordedbyJ. Shackfordand colleagues,313 of these pers. comm.). were revisited.At least 110 previousunrecorded prairie dog colonieswere found incidentallywhile trying ST^TUS OF PRAmIE DOGS IN OKt.AHOMA to verify the locationsof the previoussurvey. These In Oklahoma, black-tailed prairie dog colonies new colonies probably are a combination of newly once covered approximately 400 000 ha, but now colonized sites, colonies that were small 10 yr ago, exist only in scattered, disjunct populations (U.S. coloniesmissed by the 1988-89 survey,and colonies Fish and Wildlife Service 2000). Tyler (1968) re- for which the legal description was incorrectly reported that millions of hectaresof prairie dog col- corded in 1989 so flint the colonywas recorded as onies were found historically in Oklahoma, but absentin 1998and a "new" colonywas found nearby. that by 1968, the total area of colonies had been The minimum number of coloniespresent in 1998 reduced to 3856 ha. Historically, black-tailed prai- was302, though the actualnumber wasprobably clos- rie dogs were locally common and widespread in er to 380. Populationsizes in colonieswere not esti- the western-most counties, including Cimarron, mated in the 1998 survey,so trendscannot be deter- Texas, Beaver, Harper, and Ellis counties, but be- mined. came less common castwardinto the mixed-grass In the main part of the state, the total number prairie. Most of the decline of black-tailed prairie of prairie dog colonies appears to have declined by dogs (and presumablyBurrowing Owls) occurred about 7% (ODWC unpubl. data). In Cimarron between 1885-1925. In recent years,populations of County, the number of prairie dog colonies is es- black-tailed prairie dogs in the Oklahoma panhan- timated to have declined by 34%. This may have dle have been unstable due to sylvaticplague and been due, at least in part, to the plague outbreak active eradication programs (U.S. Fish and Wildlife that was documented there in 1991-92. However, Service 2000, S. Sheffield pers. observ.). the number of prairie dog coloniesin the two oth- A surveyof prairie dog colonieswas conducted in er panhandle counties (Texas and Beaver) seems Oklahoma for the Oklahoma Department of Wildlife to have increasedby 19%. In central Oklahoma, Conservation(ODWC) in 1988-89 (J. Shackford,J. black-tailed prairie dog colonies apparently were Tyler, and L. Choate unpubl. data). More recently, rare but some were very large. DEGEMBER2001 BURROWINGOWLS IN OKLAHOMA 355

ASSOCIATION BETWEEN BURROWING OWLS AND B•CK- Therefore,assumption that largerprairie dog col- l'AII,ED PRAIRIE DOGS IN OKIAHOMA oniesare more likely to containBurrowing OMs Tyler (1968) found 280 black-tailedprairie dog does not appear to be valid in all cases.There is coloniesin his Oklahomasurvey, and found Bur- some evidencethat BurrowingOMs are easierto rowingOwls inhabiting 40% of the prairie dog col- detectin smallerprairie dog coloniesor colonies onies checked.The largest number of oMs in a with fewer prairie dogs (M. Desmondand M. Res- single dog colony was 30 individuals.Butts and tani pets. comm.). Lewis(1982) found that, within prairie dog colo- BurrowingOwls have cDevDivedwith prairie nies, Burrowing OMs aggregatedtheir nestsinto dogs and other colonialsciurids in the prairie clustersand often concentratednests at edgesof grasslandecosystem in North America.They have black-tailedprairie dog colonies. Prairie dog colD- beenfound to be tightlyassociated with prairie dog roesappeared to be the only habitatwith sufficient colonies in Oklahoma (Tyler 1968), Nebraska densitiesof burrowsto provideboth nestingand (Desmond and Savidge 1996), South Dakota satelliteburrows. There maybe a certainminimum (Sharpsm•d Uresk 1990), and Wyoming(Camp- area of prairie dog colony(ies)required for Bur- bell m•d Clark 1981). In addition, Clark et al. rowing Owls to nest, but this threshold is not (1982) found a strong correlation between in- known.J. Shackford(unpubl. data) found owlsin creased vertebrate abundance and increased colo- regionsof the statewhere there were at least seven ny size(r = 0.81). Prairiedog coloniesprovide het- individual prairie dog coloniesor at least 162 ha erogeneousplant cover,high densitiesof prey of prairie dog coloniesin closeproximity. Black- species,high seed production, low vegetation tailed prairie dog colonies in Oklahoma became height, and good visibilityof prey and predators (Clark et al. 1982). One main benefit of this close unsuitablefor BurrowingOMs 1-3 yr after aban- donment by black-tailedprairie dogs (Buttsand associationfor both owlsand prairie dogsappears Lewis1982). They suggestedthat BurrowingOMs to be increasedprotection from predation (Des- mond et al. 2000). nesting outside of prairie dog colonies in Oklahomawere utilizing marginal habitat and may Clearly,black-tailed prairie dog coloniesare crit- icallyimportant to BurrowingOwls in Oklahoma, representindividuals forced out of preferredprai- as well as in much of the rest of midwestern North rie dog colony habitat (Buttsand Lewis 1982). America (Butts and Lewis 1982). However, Burrow- Barko et al. (1999) found that BurrowingOM ing Owl populations have suffered in Oklahoma abundancewas significantlyhigher on siteswith becauseof their close ecologicalassociation with black-tailedprairie dog coloniesthan at uncoloni- black-tailedprairie dogs. Although both black- zed sitesin Oklahomaduring the springand sum- tailed prairie dogsand BurrowingOMs were con- met. They recorded BurrowingOwls on prairie sideredlocally common in the stateprior to Eu- dog-colonizedsites of 3-302 ha (N = 5). Desmond ropean settlement,both specieswere virtually et al. (2000) found strong correlationsbetween wiped out by a statewidepoisoning campaign in BurrowingOwl and black-tailedprairie dog de- 1922 (Baumgartnerand Baumgartner1992). clinesand providedevidence of a timelag in Bur- rowingOwl populationresponse to changesin ac- OUTLOOK FOR BURROWING OWLS IN OIGAHOMA nve burrow densitiesof prairie dogsin Nebraska BurrowingOMs shouldbe able to persistin the between 1990-96. panhandle and in other western counties of In Oklahoma,there hasbeen greatvariation in Oklahoma,where there is relativelylitde develop- BurrowingOM occupationof large versussmall ment and where habitathas not been greatlyal- prairie dog colonies.Butts (1971) found a large tered. However, one problem area is Cimarron rangein the densityof nestingBurrowing Owls in County,where the major lossof prairie dog colo- prairie dog colonies.He found that largecolonies nies is causefor concern.Prairie dog coloniesin (>40.5 ha) in BeaverCounty did not haveBurrow- Oklahomashould be monitoredclosely at leastev- •ng OMs, but 19 of 21 colonies that were <4 ha in ery 2-4 yr, includingmonitoring of both Burrow- size supported Burrowing Owls. Tyler (1968) ing OMs m•d prairie dogs.If the focusof conser- fond a1 9 h• prairie dog colonyin JacksonCoun- vation efforts is on the prairic dog/grassland ty with 30 Burrowing OMs. These data indicate ecosystem,then there is a good chance that the that Burrowing OMs will utilize small colonies. Burrowing Owl also will be protected in 356 STATUSAND TRENDS VOL. 35, NO. 4

Oklahoma. Major cooperative efforts are needed dog towns to Burrowing Owls in Oklahoma. Proc to ensure that viable populations of both species Ohla. Acad. Sci. 62:46-52. CAMPBELL,TM. III AND T.W. CLAm•.1981. Colony char- continue to exist throughout their ranges in acteristics and vertebrate associates of white-tailed and Oklahoma so that they do not continue to decline black-tailed prairie dogs in Wyoming. Am. Midl. Nat toward endangered status. 105:269-276. Most of the nearly 400 prairie dog colonies in CL2mK, TW., T.M. C^MPBELL III, D.C. SOCH^, AND D.E. Oklahoma occur on private lands. This is of con- C^SEY.1982. Prairie dog colony attributes and associ- cern becausethere is a greater likelihood of habi- ated species.Great Basin Nat. 42:572-582. tat alteration and lessability to enact conservation DESMOND,MJ. ^NDJ.A. S^VIDGE.1996. Factorsinfluenc- ing Burrowing Owl (Speotytocunicularia) nest densities actions on private lands. State-sponsoredinitiatives and numbers in western Nebraska. Am. Midl. Nat. 136. to conserve prairie dog colonies on private lands 143-148. would address this situation. --, J.A. S^VIDGE,AND K.M. ESKRIDGE.2000. Correla- In 2000, the ODWG began aerial transectsurveys tions betweenBurrowing Owl and black-tailedprairie of prairie dog coloniesin Gimarron, Texas, Beaver, dog declines:a 7-yearanalysis. J. Wildl. Manage.64' 1067-1975. Harper, and Ellis counties,and in 2002 will attempt HAUG, E.A., B.A. M1LLS•P, ^Nr) M.S. MARTELL. 1993. Bur- to ground-truth colonies that were identified dur- rowing Owl (Speotytocunicularia). In A. Poole and F ing the aerial survey.Burrowing Owlswill be mon- Gill [EDS.], The birds of North America, No. 61. The itored during this effort. Academy of Natural Sciences,Philadelphia, PA and Finally, Burrowing Owl mortality factors, such as American Ornithologists' Union, Washington, DC pesticidepoisoning, can be significantin some ar- U.S.A. eas of Oklahoma, particularly in agricultural and HOLROYD, G.L., R. RODRiGUEZ-ESTRELLA,AND S.R. SHEF- rangeland areaswhere pesticidesare applied, and F•};LD.2001. Conservation of the Burrowing OM m western North America: issues,challenges, and rec- both direct and secondary poisoning can occur ommendations.J. RaptorRes. 35:399-407. (Sheffield 1997b). Conservationand management S^UER,J.R., S. SCHWARTZ,AND B. HOOVER.1996. Christ- measures, education, and changes in both public mas bird count summary and analysis.Version 95.1 attitndes and policies are necessaryfor the contin- PatuxentWildl. Res. Center, Laurel, MD U.S.A. http'/ ued existence of viable populations of Burrowing /www.mbr. nbs.gov / cbc/ cbcnew.html. Owls and grassland sciurids in Oklahoma and in , J.E. HINES,I. THOMAS,J. FALLON,^ND G. GOUrSH. 2000. The North American breeding bird survey,re- North America in general (Holroyd et al. 2001). suitsand analysis.Version 98.1. Patuxent Wildlife Re- ACKNOWLEDGMENTS search Center, Laurel, MD U.S.A. http://www. mbr- pwrc.usgs.gov/bbs. We thank J.S. Shackford,J.D. Tyler, and L.L. Choate SH2mPS,J. ANDD. URESK.1990. Ecologicalreview of black- for information on black-tailed prairie dogs in tailed prairie dogs and associatedspecies in western Oklahoma, D. Reinking fbr information on Burrowing South Dakota. Great Basin Nat. 50:339-345. Owls and prairie dogsseen during the OklahomaBreed- ing Bird Atlas, M.J. DestoGrid,S.W. Gillihan, T.I. Welli- SHEFFIELD,S.R. 1997a. Current status, distribution, and come, and an anonymousreviewer for providing helpful conservationof the Burrowing Owl in midwestern comments on this paper, and G.I, Holroyd for his efforts and western North America. Pages 399-408 in J.R •n organizingthe 2•d InternationalBurrowing Owl Sym- Duncan, D.H. Johnson, and T.H. Nicholls [EDS.], Bi- posium in Ogden, Utah. ologyand conservationof owlsof the northern hem•- sphere: 2rid international symposium.USDA Gem LITERATURE CII ED Tech. Rep. NC-190, St. Paul, MN U.S.A. B,•m<(),V.A., J.H. SIIAW,AND I).M. I•I•SLm,JR. 1999. Birds 1997b. Owls as biGmonitors of environmental associatedwilh black-tailed prairie dog colonies in health hazards.Pages 383-398 in.J.R. Duncan, D.H southern shortgrassprairie. Southwest.Nat. 44:484- .Johnson,and T.H. Nicholls [EDS.],Biology and con- 489. servation of owls of the northern hemisphere: 2rid BAUMGARTNER, F.M. AND A.M. BAUMGARTNER. 1992. international symposium.USDA Gem Tech. Rep. NC- Oklahoma bird life. Univ. Oklahoma Press, Norman, 190, St. Paul, MN U.S.A. OK U.S.A. T'a•F•R,J.D. 1968. Distribution and vertebrateassociates of BUTTS,K.O. 1971. Observationson the ecologyof Bur- the black-tailed prairie dog in Oklahoma. Ph.D. &s- rowing OMs in westernOklahoma: a preliminary re- sertation, Univ. Oklahoma, Norman, OK U.S.A. port. Proc.Okla. Acad. Sei. 51:66-74. U.S. FISHAND WILDLIFE SERVICE. 2000. Endangeredand 1976. Burrowing Owls wintering in the threatenedwildlife and plants; 12-monthfinding for Oklahoma panhandle. Auk 93;510-516. a petition to list the black-tailedprairie dog asthreat- -- ANnJ.C. LEwis. 1982. The importance of prairie ened. FederalRegister 65:5476-5488.