Federal Register/Vol. 63, No. 92/Wednesday, May 13, 1998

Federal Register / Vol. 63, No. 92 / Wednesday, May 13, 1998 / Rules and Regulations 26517 upgrading is appropriate, based on the by appointment, during normal business terms reflect common usage). Krutzsch incremental benefits and costs and applicable hours at the U.S. Fish and Wildlife (1954) also provided a technical statutory criteria, the agency issues an NPRM Service's Colorado Field Office, 755 description of the skull of Preble's, proposing to upgrade the FMVSS to the level which can prove important to its of Country B's std. If upgrading is not Parfet Street, Suite 361, Lakewood, appropriate, NHTSA considers issuing an Colorado. identification. NPRM proposing to add the requirements of FOR FURTHER INFORMATION CONTACT: There is a similarity of appearance Country B's std to the FMVSS as an LeRoy W. Carlson, Field Supervisor, between the Preble's meadow jumping alternative compliance option. The proposal Colorado Field Office, U.S. Fish and mouse and Z. princeps, which also to add the compliance option would set forth Wildlife Service, P.O. Box 25486, occurs in portions of Colorado and the basis for the agency's conclusion that Denver Federal Center, Denver, Wyoming. In general, Z. hudsonius may upgrading the FMVSS is inappropriate. be distinguished from Z. princeps by If NHTSA issues an NPRM, it would request Colorado 80225±0207 (telephone 303/ 275±2370). average external size and cranial size comment on the tentative determination and (Krutzsch 1954, Whitaker 1972). the proposed amendment. SUPPLEMENTARY INFORMATION: 3. Decision whether to issue a final rule. Preble's may be distinguished from Z. Any final decision to make a determination Background princeps by a less pronounced mid- regarding relative benefits and functional The Preble's meadow jumping mouse dorsal band, smaller average total equivalency and to amend the FMVSS will length, and a skull that is small and (Zapus hudsonius preblei) (Preble's) is a be made in accordance with the process in light with a narrower braincase and small rodent in the family Zapodidae the flowchart and applicable law and only smaller molars (Fitzgerald et al. 1994). and is 1 of 12 recognized subspecies of after careful consideration and analysis of the Since coloration of the mid-dorsal band the species Z. hudsonius, the meadow public comments. and total length are not definitive jumping mouse (Krutzsch 1954, Issued on May 6, 1998. characteristics, skull measurements are Whitaker 1972, Hafner 1981). The Ricardo Martinez, most useful for positive identification. family Zapus consists of small to Administrator. Ranges of the Preble's and Z. princeps medium-sized mice with long tails and [FR Doc. 98±12598 Filed 5±12±98; 8:45 am] are not known to overlap in Colorado long feet adapted for jumping. Krutzsch BILLING CODE 4910±59±P but the relationships between respective (1954) provided a revision of the ranges in Wyoming is less clear (Garber taxonomy of the genus Zapus in North 1995, Armstrong 1972). America and recognized three living DEPARTMENT OF THE INTERIOR Krutzsch (1954) commented on the species, Z. hudsonius, Z. trinotatus, and presence of physical habitat barriers and Fish and Wildlife Service Z. princeps. As the most recent revision lack of known intergradation between of Z. hudsonius, this stands as the the Preble's meadow jumping mouse, 50 CFR Part 17 authority for taxonomy. Fitzgerald et al. known only from eastern Colorado and (1994) described Z. hudsonius as RIN 1018±AE06 southeastern Wyoming, and other greyish to yellowish-brown in color identified subspecies of Z. hudsonius Endangered and Threatened Wildlife with an indistinct mid-dorsal band of ranging to the east and north. Among and Plants; Final Rule to List the darker hair and paler sides, large recognized subspecies, Krutzsch found Preble's Meadow Jumping Mouse as a hindlegs and hindfeet, and a sparsely that Preble's most closely resembled Z. Threatened Species haired tail that accounts for more than campestris from northeastern Wyoming, 60 percent of the total length. but summarized differences in AGENCY: Fish and Wildlife Service, In his 1899 revision of North coloration and skull characteristics. Interior. American jumping mice, E. A. Preble Krutzsch concluded that considerable ACTION: Final rule. referred specimens of the meadow differences existed between Preble's and jumping mouse from Colorado and related subspecies. In contrast, Jones SUMMARY: The U.S. Fish and Wildlife southeastern Wyoming to the subspecies (1981) studied specific and intraspecific Service determines the Preble's meadow Z. h. campestris (Preble 1899, cited by relationships within Zapus and jumping mouse (Zapus hudsonius Krutzsch 1954). Krutzsch (1954) recognized no subspecies of Z. preblei) to be a threatened species described and named Z. h. preblei as hudsonius. Jones did, however cite that pursuant to the Endangered Species Act separate from Z. h. campestris, Z. hudsonius populations in Colorado (Act) of 1973, as amended. The Preble's indicating as the holotype a specimen and southeastern Wyoming were meadow jumping mouse, a small rodent obtained by E. A. Preble in July 1895 apparently isolated from other in the family Zapodidae, is known to from Loveland, Larimer County, populations. Hafner et al. (1981) occur in seven counties in Colorado and Colorado. All records of Preble's are described an additional subspecies Z. two counties in Wyoming. Historical from southeastern Wyoming and eastern hudsonius luteus present in New records document its former presence in Colorado. The coloration of Preble's was Mexico and Arizona and differentiated additional counties in Colorado and described by Krutzsch (1954) as ``color it from Preble's. This subspecies was Wyoming. The Preble's meadow dull, back from near Clay Color to near previously considered Z. princeps jumping mouse lives primarily in Tawny-Olive with a mixture of black luteus, a subspecies of the western heavily vegetated riparian habitats. hair forming poorly defined dorsal jumping mouse. Recently, Z. h. luteus Habitat loss and degradation caused by band; sides lighter than back from near was found in Las Animas County, agricultural, residential, commercial, Clay Color to near Cinnamon-Buff; Colorado (Riggs et al. 1997), the furthest and industrial development imperil its lateral line distinct and clear north that the subspecies has been continued existence. This action Ochraceous-Buff; belly white, recorded, but over 100 miles south of implements the protection of the Act for sometimes faint wash of clear the confirmed range of Preble's in Preble's meadow jumping mouse. Ochraceous-Buff; tail bicolored, Colorado. DATES: This rule is effective June 12, brownish to light brownish-black above, Results from genetic analysis of mice 1998. grayish-white to yellowish-white from Rocky Flats Environmental ADDRESSES: The complete file for this below'' (capitalized color terms refer to Technology Site (Rocky Flats) in rule is available for public inspection, a scientific standard, while lower case Jefferson County, Colorado, Z. 26518 Federal Register / Vol. 63, No. 92 / Wednesday, May 13, 1998 / Rules and Regulations hudsonius from Minnesota and Indiana, mice from F.E. Warren Air Force Base, and habitat utilization have been and, Z. princeps from Colorado, Laramie County, Wyoming, were documented. Armstrong et al. (1997) provided clear evidence that the Rocky identified as Preble's when they were and Shenk (in litt. 1998) have compiled Flats mice were of the species Z. trapped and later determined to be most summaries of information on Preble's hudsonius. However, the analysis did similar to Z. princeps (Riggs et al. 1997). gleaned from recent studies. Data on the not provide a means of separating Hafner (1998) suggested that the timing of the initial breeding period and subspecies of Z. hudsonius (Bruce discrepancies in species associations time of hibernation of the Preble's Wunder, Colorado State University, found in the analysis by Riggs et al. meadow jumping mouse have been pers. comm. 1996). Under a cost-sharing (1997) could be due to the specific DNA gathered by researchers at Rocky Flats agreement with the U.S. Fish and segment chosen for analysis, or to (PTI Environmental Services 1996a). Wildlife Service, the Colorado Division limited hybridization in areas where the The month of May marks the beginning of Wildlife supported genetic studies of two species' ranges overlap. Riggs et al. of the active period for Preble's, with Preble's trapped in Colorado and (1997), Hafner (1998), Tanya Shenk May 5 the earliest capture date at Rocky Wyoming during the 1996 and 1997 (Colorado Division of Wildlife, in litt. Flats. Breeding probably occurs soon field seasons. Tissue samples from 1998), and David Armstrong (University after emergence. Adults begin presumed Preble's trapped at 23 of Colorado, in litt. 1998) encouraged hibernation in early September, while locations in Colorado and 2 in Wyoming additional genetic and morphological juveniles enter hibernation from mid- were assessed, through mitochondrial investigations to further define September to late October. The latest DNA analysis, and compared to relationships among Zapus in the recorded date of capture of Preble's at reference samples of Z. princeps and to region. Rocky Flats is October 27. Adults reach samples of Z. hudsonius from outside The Preble's meadow jumping mouse approximately 20 percent body fat the known range of Preble's. The has not been studied as extensively as before going into hibernation (Wunder analysis indicated that mice from other subspecies of Z. hudsonius have pers. com. 1997). Albany County, Wyoming (Medicine been studied elsewhere. Preble's is Little information exists on Preble's Bow National Forest) to western Las thought to be similar to other Z. meadow jumping mouse food Animas County, Colorado (San Isabel hudsonius in patterns of diet, behavior, preferences. It has been speculated that National Forest) formed a coherent breeding, and habitat utilization. In Preble's may need an open water source genetic group (Riggs et al.

Load more