Occasional Papers Museum of Texas Tech University NUMBER 190 1 April 1999 THE NORTHERN ROCK MOUSE, PEROMYSCUS NASUTUS (MAMMALIA: RODENTIA), FROM THE DAVIS MOUNTAINS, TEXAS Robert D. Bradley, David J. Schmidly, and Clyde Jones The northern rock mouse ( Peromyscus nasutus ) has a rather unusual geographic distribution in the Trans-Pecos region of Texas, occurring in several dis¬ junct areas. Schmidly (1977) mapped two places of occurrence of P. nasutus in the Franklin Mountains, El Paso County, three localities in the Guadalupe Moun¬ tains, Culberson County, one site in the Chinati Moun¬ tains, Presidio County, and one locality in the Chisos Mountains, Brewster County, Stangl et al. (1994) ex¬ amined specimens only from the Guadalupe Moun¬ tains. A record for Jeff Davis County was reported by Davis and Schmidly (1994); however, one of us (DJS) has examined that specimen and confirmed that it is a P. boylii and not a P. nasutus. Therefore, the northern rock mouse has been reported to occur only at a total of seven disjunct localities in four counties of the Trans-Pecos region. On 7 November 1998, we obtained two speci¬ mens of P. nasutus (non-pregnant females) on the Mount Livermore Preserve, Davis Mountains, Jeff Davis County, Texas (UTM coordinates 13579953E 3389870N). The mice were trapped among rocks on north-facing slopes of Mount Livermore. The domi¬ nant vegetation was a pine-oak-juniper woodland, with some ferns and mosses and a layer of litter composed mostly of pine needles and oak leaves present among the rocks. This capture site is typical of habitats where P. nasutus has been found elsewhere in the region, however, Stangl et al. (1994) reported two specimens from a rocky area adjacent to a hillside with lechuguilla (Agave lechuguilla ) and sotol (Dasylirion sp.), which they considered as atypical habitat for P. nasutus. Other species of mammals collected in the vicinity on Mount Livermore included the brush mouse (P. boylii) and western harvest mouse (Reithrodontomys megalotis). However, these species were not taken in the moist, rocky areas where P. nasutus was found; this separa¬ tion of ecological niches was discussed by Schmidly (1977) and Davis and Schmidly (1994). We agree with Carleton (1989) with regard to use of the name P , nasutus for the northern rock mouse. This arrangement was accepted by Davis and Schmidly (1994), Jones et al. (1997), and Manning and Jones (1998), however, Stangl et al. (1994) chose to retain the name P. difficilis to refer to this form. The sys¬ tematic relationships of subspecies of P. nasutus in Texas is not clear. The subspecies recognized cur¬ rently are P. n. nasutus (J.A. Allen, 1891) from the 2 OCCASIONAL PAPERS, MUSEUM OF TEXAS TECH UNIVERSITY Guadalupe Mountains of Culberson County, and P. n, penicillatus Mearns, 1896, from Brewster, Presidio, and El Paso counties (Manning and Jones, 1998). Ad¬ ditional analyses are needed in order to determine the subspecific affinities of the northern rock mice from the Davis Mountains in Jeff Davis County, Texas. The specimens of P. nasutus from the Davis Mountains reported above (TTU 78316, 78317), as well as frozen tissues (TK 83756, 83590), and a karyo¬ type of one specimen (TTU 78317), are deposited in the collection of Recent Mammals in the Natural Sci¬ ence Research Laboratory, the Museum of Texas Tech University. Specimens were collected from the Mount Livermore Preserve in accordance with scientific col¬ lecting permits issued by the Texas Parks and Wildlife Department (permit number SPR-0790-189 and SPR- 0393-593). Access and permission to work on the Mount Livermore Preserve were granted by the Na¬ ture Conservancy of Texas (John Karges and Jason Wrinkle). Financial support was provided through a partnership between the nature Conservancy of Texas and Texas Tech University. Collection and prepara¬ tion of specimens was with the assistance of Irene Tiemann, Melinda Clary, Cole Matson, and Justin Bryan. Karyotypic analysis was conducted by Brenda Rodgers and Robert Baker. LITERATURE CITED Carleton, M.D. 1989. Systematics and evolution. Pp. 7-141 in Advances in the study of Peromyscus (Rodentia), G.L. Kirkland, Jr., and J.N. Layne, eds., Texas Tech Univ. Press, Lubbock, iv + 367 pp. Davis, W.B., and D.J. Schmidly, 1994. The mammals of Texas. Texas Parks and Wildlife Department, Austin, x + 338 pp. Jones, C., R.S. Hoffman, D. W. Rice, M.D. Engstrom, R.D. Bra¬ dley, D.J. Schmidly, C.A. Jones, and R.J. Baker. 1997. Revised checklist of North American mammals north of Mexico, 1997, Occas. Papers, Mus., Texas Tech Univ., 173:1-19. Manning, R,W., and C, Jones. 1998. Annotated checklist of Recent land mammals of Texas, 1998. Occas, Papers, Mus., Texas Tech Univ., 182:1-20. Schmidly, D.J. 1977, The mammals of Trans-Pecos Texas including Big Bend National Park and Guadalupe Moun¬ tains National Park. Texas A&M Unv. Press, College Station, xiii + 225 pp. Stangl, F.B., Jr., W.W, Dalquest, and R.R. Hollander. 1994. Evolution of a desert mammalian fauna: A 10,000-year history of mammals from Culberson and Jeff Davis coun¬ ties, Trans-Pecos Texas, Midwestern State Univ. Press, Wichita Falls, Texas, xix + 264 pp. BRADLEY ET AL .—PEROMYSCUS NASUTUS FROM THE DAVIS MOUNTAINS 3 Addresses of authors: ROBERT D. BRADLEY Department of Biological Sciences and Museum of Texas Tech University Lubbock, Texas 79409 e-mail address: izrdb@ttacs.ttu.edu CLYDEJONES Department of Biological Sciences and Museum of Texas Tech University Lubbock, Texas 79409 e-mail address: cjones@packrat.musm.ttu.edu DAVID J.SCHMIDLY Natural Science Research Laboratory 1 Museum of Texas Tech University Lubbock, Texas 79409 e-mail address: schmidly@ttu.edu PUBLICATIONS OF THE MUSEUM OF TEXAS TECH UNIVERSITY It was through the efforts of Horn Professor J Knox Jones, as director of Academic Publications, that Texas Tech University initiated several publications series including the Occasional Papers of the Museum, I his and future editions in the series are a memorial to his dedication to excellence in academic publications. Proles¬ sor Jones enjoyed editing scientific publications and served the scientific community as an editor for the Journal of Mammalogy, Evolution, The Texas Journal of Science, Occasional Papers of the Museum, and Special Publications of the Museum. It is with special fondness that we remember Dr. J Knox Jones. Institutional subscriptions are available through the Museum of Texas Tech University, attn: NSRL Publica¬ tions Secretary, Box 43191, Lubbock, TX 79409-3191. Individuals may also purchase separate numbers of the Occasional Papers directly from the Museum of Texas Tech University. ISSN 0149-175X Museum of Texas Tech University, Lubbock, TX 79409-3191