The Southwestern h'aturallst vol. 38, no. 2

NOTES ON THE DISTRIBUTION OF THE MOGOLLON VOLE (MICROTUS MOGOLLONENSIS) IN NEW MEXICO AND ARIZONA

Museum of Southwestern Biology, Department of Btology, University of New Mexico, Albuquerque, NM 87131 Peabody Coal Company, Western Diz~ision, Post Osee Box 605, Kayenta, AZ 86033

Microtus mogollonensis (Mearns), here recog- Jones, 1962), most records are from plateaus and nized as distinct from M. mexicanus (Saussure) mountains which have vegetation zones of pon- based on the studies of Judd (1980), Modi (1 987), derosa pine and often up to spruce-fir (Picea en- and Frey (1989), occurs in New Mexico and glemannii-Abies lasiocarpa) forest. The Mogollon Arizona with peripheral populations in Utah, vole has been reported to descend in elevation into Colorado, and Texas (Hall, 1981; Fig. 1). Micro- pinyon-juniper (Pinus edulis-juniperus osteo- t2is mogollonensis is confined mainly to montane sperma) woodland from ponderosa pine forest dur- areas where it prefers grassy habitats in ponder- ing periods of high population densities (Findley osa pine (Pinus ponderosa) and mixed coniferous et al., 1975). On 9 August 1991, one of us (JKF) forests (Findley et al., 1975; Hoffmeister, 1986). collected 17 M. mogollonensis from a large open Several notable gaps appear to exist within the meadow with scattered shrubs in the Jicarilla species' range. However, recent collections sug- Mountains (elevation approximately 2,134 m; Fig. gest that at least some of the gaps are not real. 1). The Jicarilla Mountains exhibit relatively The purpose of this paper is to report the presence xeric conditions and represent only the second of M. mogollonensis from six new localities in New locality in a mountain range where vegetation Mexico and Arizona. zones reach only as high as pinyon-juniper In New Mexico, the range of M. mogollonensis woodland (the other locality is Capulin Moun- has been reviewed by Bailey (1931 [=1932]), Fin- tain, Union Co., New Mexico, at the northeastern dley and Jones (1962), Findley et al. (1975), edge of the range). Dominant plant species in- Finley et al. (1986), and Hubbard et al. (1983). clude Colorado pinyon (Pinus edulis), junipers We examined five specimens of M. mogollonensis (including juniperus deppeana), and oaks ((2uer- from the Pinos Altos Range collected by students cus sp.). Ponderosa pines are rare and limited to under the direction of Bruce J. Hayward and widely scattered individuals. At this locality, M. Charles S. Thaeler, Jr., during 1969, 1970, and mogolionensis selectively utilized relatively shady 1979 (Fig. 1). The presence of M. mogollonensis and grassy microhabitats. Vole activity, as indi- on this mountain range was expected because of cated by runways and captures, was typically the relatively moderate size, high elevations (to restricted to the northeast sides of shrubs. Run- 2,727 m), and extensive development of ponder- ways rarely extended beyond where afternoon osa pine forest and higher vegetation zones. In shade would usually be available. addition, the Pinos Altos Range is in close prox- In Arizona, the distribution of M. mogollonensis imity to the Mogollon Mountains and Black has been reviewed by Cockrum (1960[=1961]) Range where these voles are known to occur (Fin- and Hoffmeister (1986). We examined two spec- dley et al., 1975; Fig. 1). imens of M. mogollonensis collected during a Bu- On 5 August 1984, Jack F. Cully, Jr., collected reau of Land Management survey of reptiles and two Mogollon voles from the alli in as Mountains amphibians during late spring 1981 from local- (Fig. I), an isolated range with ponderosa pine ities in the northern Music Mountains (Fig. 1). forest at the highest elevations, and one of the The Music Mountains are a relatively low range smallest massifs (approximately 5 by 12 km, (maximum elevation 2,036 m) and the habitat is maximum elevation 2,626 m) on which the Mo- ecotonal between ponderosa pine forest and chap- gollon vole is known to occur. arral (including Pinus monophylla, Juniperus Although M. rnogollonensis is the most xeric- monosperma, Arctostaphylos sp., and Quercus tur- adapted of southwestern vole species (Findley and binella). The specimens were collected from el- June 1993 Notes 177

FIG.I-Distribution of Microtus mogollonensis (shading). Localities discussed in the text include 1) Gallinas Mountains, 2) Jicarilla Mountains, 3) Black Range, 4) Pinos Altos Range, 5) Mogollon Mountains, 6) Defiance Plateau and Chuska Mountains, 7) Black Mesa, and 8) Prospect Valley, 9) Music Mountains, 10) Hualapai Mountains. Thin lines are 2,134-m contour intervals south of the Colorado River. See Appendix for specific localities.

evations of 1,670 m and 1,707 m, representing On 11 August 1986, Gary L. Graham collected two of the lowest elevational records for the spe- a Mogollon vole from the Defiance Plateau (Fig. cies. In addition, these new localities of record I), a large, westward extension of the Chuska represent the northwesternmost for the species. Mountains that supports extensive ponderosa pine The nearest previously known localities for the forest. Most recently, on 24 June 1992, M. mog- species are approximately 77 km south in the ollonensis was collected by one of us (JKF) from Hualapai Mountains and 87 km east in Prospect Wheatfields Lake (elevation approximately 2,225 Valley (Fig. 1). m) at the base of the Chuska Mountains on the On 29 April 1984, one of us (CTL) collected northeastern end of the Defiance Plateau. Since M. mogollonensis from the northern end of Black at least 1931, Microtus longicaudus was the only Mesa (Fig. 1). Black Mesa is a large plateau microtine known from the Chuska Mountains (maximum elevation 2,490 m) dominated by pin- (Bailey, 1931[=1932]). Furthermore, although yon-juniper woodland and big sagebrush (Arte- M. longicaudus previously was known from misia tridentata) shrubland, but north-facing slopes Wheatfields Creek (Cockrum, 1960[=1961]) near and protected areas support ponderosa pine and the new locality for M. mogollonensis reported Douglas fir (Pseudotsuga menziesii). The Mogo- here, M. longicaudus was no: collected along with llon vole has been collected on the mesa from specimens of M. mogollonenszs from Wheatfields elevations as low as 1,884 m (see Appendix). Lake in 1992. 178 The Southwestern ~\'aturalist vol. 38, no. 2

We thank the curators who allowed us to ex- Cricetidae) in New Mexico. Nemouria: Occas. Pa- amine specimens. Helpful information was pro- pers Delaware Mus. Nat. Hist., 28:l-8. vided by D. Belitsky, J. F. Cully, Jr., B. J. JUDD,S. R. 1980. Observations of the chromosome Hayward, R. B. Spicer, and C. S. Thaeler, Jr. variation in Microtus mexicanus (Rodentia: Micro- Special thanks to J. P. Hubbard who provided tinae). Mamm. Chromosome Newsl., 21:llO-113. MODI,W. S. 1987. Phylogenetic analyses of chro- extensive comments and suggestions on a previous mosomal banding patterns among the nearctic .4rvi- version of this manuscript and D. W. Moore who colidae (Mammalia: Rodentia). Syst. Zool., 36:109- helped with some of the field work and provided 136. helpful suggestions. Finally, we thank F. W. Da- vis, W. L. Gannon, J. B. M. Miyashiro, R. E. Palma, and J.A. Salazar for providing comments on a previous version of this manuscript. Portions Specimens were examined from the following col- of this research were partially funded (to JKF) lections: University of Arizona (UA); New Mexico State University (NMSU); Museum of Southwestern by grants from the University of New Mexico Biology, University of New Mexico (MSB); Western Student Research Allocations Committee, De- New Mexico University (WNMU); New Mexico Mu- partment of Biology Graduate Research Alloca- seum of Natural History (NMMNH). tions Committee, University of New Mexico, and ARIZONA: Apache Co.; Black Mesa, 0.3 mi. W, Sigma Xi. 0.2 mi. N Black Mesa Pass on Rd from Rough Rock to Black Mesa, 7,200 ft. (1, MSB); 0.5 mi. N, 2.6 mi. W Fluted Rock, 7,820 ft., 35 53'35", 109 18'03" (1, NMMNH); Navajo Nation, Chuska Mountains, BAILEY,V. 1931(=1932). Mammals of New Mexico. Wheatfields Lake dam, 14.4 mi. S, 6.8 mi. E Lukachu- N. Amer. Fauna, 53:l-412. kai, 2,225 m (4, MSB). Mohave Co.; Music Mtn., COCKRUM,E. L. 1960(=1961). The Recent mam- T28N, R16W, SE % Sec. 36 (1, UA); Music Mt., mals of Arizona: their taxonomy and distribution. T28N, R16W, NW '/4 Sec. 30 (1, UA). Navajo Co.; Univ. Arizona Press, Tucson. Black Mesa, Yellow Water Canyon, 4.25 mi. W, 8.7 FINDLEY,J. S., AND C. J. JONES. 1962. Distribution mi. S of Kayenta, 7,100 ft. (23, MSB); Black Mesa, and variation of voles of the genus Microtus in New Peabody Coal Co. lease, N-7 reclaimed area, 10.5 mi. Mexico and adjacent areas. J. Mamm., 43:154- S, 10.0 mi. W of Kayenta, El. 6,800 ft. (2, MSB); 166. Black Mesa, Peabody lease, Moenkopi Wash, 6,180 FINDLEY,J. S., A. H. HARRIS,D. E. WILSON,AND C. ft. (2, MSB); Black Mesa, Peabody Coal Co. lease, JONES. 1975. Mammals of New Mexico. Univ. J-7(1B) RCA (1, MSB); Black Mesa, Peabody Coal New Mexico Press, Albuquerque. Co. Lease, J-16(2) RCA (1, MSB); Black Mesa, Pea- FINLEY,R. B., JR., J.R. CHOATE,AND D. F. HOFFMEI- body Coal Co. lease, Pond J-l6L (1, MSB); Black STER. 1986. Distributions and habitats of voles Mesa, Peabody Coal Co. Lease, Pond N-14G (3, MSB); in southeastern Colorado and northeastern New Black Mesa, Peabody Coal Co. lease, Pond J-28C (6, Mexico. J. Mamm., 31:263-266. MSB); Black Mesa, Peabody Coal Co. lease, Pond FREY,J. K. 1989. Morphologic variation in the Mex- J-28B (7, MSB); Black Mesa, Peabody Coal Co. lease, ican vole (Microtus mexicanus). Unpubl. M.S. the- N-2 RCA, 250 m W of Rd. N-2RA (AKA N-2-12), sis, Emporia State Univ., Emporia, Kansas. 6,570 ft. (2, MSB). HALL,E. R. 1981. The mammals of North America. NEW MEXICO: Grant Co.; 5 mi. N Pinos Altos Second ed. John Wiley and Sons, New York, 11: on NM HW 15, T16S, R13W, Sec. 9, 7,225 ft. (1, 601-1181 + 90 unnumbered. WNMU); 11.5 mi. NE Pinos Altos, Lake Roberts (2, HOFFMEISTER,D. F. 1986. Mammals of Arizona. WNMU); upper end Lake Roberts (1, WNMU); 3.4 Univ. Arizona Press and Arizona Game Fish Dept., mi. N, 0.2 mi. E Pinos Altos (1, NMSU). Lincoln Co.; Tucson. Gallinas Mtn. (2, MSB); Jicarilla Mountains, 0.9 mi. HUBBARD,J. P., C. S. THAELER,JR., AND C. G. SE Jicarilla, T5S, R12E, E 'h Sec. 23 (17, MSB). SCHMITT. 1983. Notes on voles (Microtus, Family