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302. Southern White-ankled Deermouse Peromyscus pectoralis French: Péromyscus a chevilles blanches / German: Stdliche WeiRRfessel-Hirschmaus / Spanish: Raton ciervo de tobillo blanco meridional Other common names: Encinal Mouse Taxonomy. Peromyscus attwateri pectoralis Osgood, 1904, Jalpan, Querétaro, Mexico. Peromyscus pectoralis is in the true: species group. Recent taxonomic revisions elevated subspecies laceianus to species status (P. laceranus) and led to the recognition of an additional subspecies (P. p. zimmermani). Three subspecies recognized. Subspecies and Distribution. P.p.pectoralisOsgood,1904—fromNCChihuahuaStoNJalisco,CGuanajuato,Querétaro,andWHidalgo,Mexico. P.p.collinusHooper,1952—fromNCTamaulipasStoEHidalgo,Mexico. P.p. zimmermani Bradley et al., 2015 — from N Coahuila S to extreme NE Jalisco and extreme NW Guanajuato, Mexico. Descriptive notes. Head—body ¢.94-99 mm, tail 81-127 mm, ear 22-26 mm, hindfoot 19-23 mm; weight 15-19 g. The Southern White-ankled Deermouse is medium-sized, with dorsum of pale ocherous buff overlaid with dusky hairs to darker brown. Venter is creamy white, and some individuals have buff pectoral spot. Hindfeet are white, with white extending above ankles. Tail generally is longer than head-body length, slightly bicolored, and scantily haired; however, it is more uniformly colored in subspecies collinus. The Southern White-ankled Deermouse is similar to the Brush Deermouse (P. boylir), but it is smaller and has white ankles. Habitat. Semiarid regions in chaparral, pinyon-oak forest, xeric shrub, and grasslands but also tropical habitats at elevations of 100-2500 m. The Southern White-ankled Deermouse prefers rocky habitats and hillsides. Food and Feeding. The Southern White-ankled Deermouse eats seeds, nuts, juniper berries, acorns, hackberries, cacti, prickly pear fruits, and sometimes insects. Breeding. The Southern White-ankled Deermouse might breed year-round. Gestation is probably c.23 days, and litters have 2-7 young. Activity patterns. The Southern White-ankled Deermouse is nocturnal. Movements, Home range and Social organization. No information. Status and Conservation. Classified as Least Concern on The IUCN Red Last. Bibliography. Bradley, Durish et al. (2007), Bradley, Schmidly et al. (2015), Musser & Carleton (2005), Oliva (2014), Schmidly (1974b)., Published as part of Don E. Wilson, Russell A. Mittermeier & Thomas E. Lacher, Jr, 2017, Cricetidae, pp. 204-535 in Handbook of the Mammals of the World – Volume 7 Rodents II, Barcelona :Lynx Edicions on page 394, DOI: 10.5281/zenodo.6707142

The white-ankled mouse (Peromyscus pectoralis) was previously known only from Carls- bad Caverns National Park and nearby areas in extreme southeastern New Mexico. I discovered 15 new localities for P. pectoralis, which extend its distribution 225 km north-northwest. This new distribution does not represent a recent northward expansion of P. pectoralis in New Mexico but reflects the lack of mammalian surveys in the region and misidentification of museum specimens from past surveys. At present, the distribution of P. pectoralis in New Mexico includes the Guada- lupe Mountains and lowland habitats between the Sacramento Mountains and Pecos River. R ESUMEN Previamente, el raton de tobillo blanco (Peromyscus pectoralis )s olo se conocia en el Parque Nacional de las Cavernas de Carlsbad y localidades adyacentes en el extremo sureste de Nuevo Mexico. Descubri ´ 15 localidades nuevas para P. pectoralis que extienden su distribucion 225 km hacia el nor-noreste. Esta nueva distribucion no representa una expansion reciente de P. pectoralis en Nuevo Mexico sino que refleja la falta de muestreos de mamiferos en la region y la mala identificacion de especimenes en museos de muestreos anteriores. Hoy en dia, la distribucion de P. pectoralis en Nuevo Mexico incluye las Guadalupe Mountains y los habitats de tierras bajas entre las Sacramento Mountains y el Pecos River.

Trypanosoma cruzi, the causative agent of Chagas' disease, is an important public health and veterinary pathogen. Although human cases are rare in the United States, infections in wildlife, and in some areas domestic dogs, are common. In 2008 and 2010, we investigated T. cruzi prevalence in possible vertebrate reservoirs in southern Texas, with an emphasis on southern plains woodrats (Neotoma micropus). Infection status was determined using a combination of culture isolation, polymerase chain reaction (PCR), and serologic testing. Based on PCR and/or culture, T. cruzi was detected in 35 of 104 (34%) woodrats, 3 of 4 (75%) striped skunks (Mephitis mephitis), 12 of 20 (60%) raccoons (Procyon lotor), and 5 of 28 (18%) other rodents including a hispid cotton rat (Sigmodon hispidus), rock squirrel (Otospermophilus variegatus), black rat (Rattus rattus), and two house mice (Mus musculus). Additionally, another Trypanosoma species was detected in 41 woodrats, of which 27 were co-infected with T. cruzi. Genetic characterization of T. cruzi revealed that raccoon, rock squirrel, and cotton rat isolates were genotype TcIV, while woodrats and skunks were infected with TcI and TcIV. Based on the Chagas Stat-Pak assay, antibodies were detected in 27 woodrats (26%), 13 raccoons (65%), 4 skunks (100%), and 5 other rodents (18%) (two white-ankled mice [Peromyscus pectoralis laceianus], two house mice, and a rock squirrel). Seroprevalence based on indirect immunofluorescence antibody testing was higher for both woodrats (37%) and raccoons (90%), compared with the Chagas Stat-Pak. This is the first report of T. cruzi in a hispid cotton rat, black rat, rock squirrel, and white-ankled mouse. These data indicate that based on culture and PCR testing, the prevalence of T. cruzi in woodrats is comparable with other common reservoirs (i.e., raccoons and opossums) in the United States. However, unlike raccoons and opossums, which tend to be infected with a particular genotype, southern plains woodrats were infected with TcI and TcIV at near equal frequencies.

We traced the three-dimensional movements of Peromyscus pectoralis in the absence of potential competitors by the fluorescent-pigment technique. P. pectoralis left 89.5% of pigment trails on ground, 9.5% on cliffs, and 1.0% in shrubs and trees. The infrequent use of trees by P. pectoralis in the absence of Peromyscus attwateri , a syntopic species in portions of the distribution of P. pectoralis , provides evidence that the pattern of habitat use by P. pectoralis is related to inherent selection rather than competitive interactions.

Peromyscus pectoralis Osgood, 1904. Proc. Biol. Soc. Washington, 17:59. TYPE LOCALITY: Mexico, Queretaro, Jalpan. DISTRIBUTION: SE New Mexico and C Texas, USA, south to N Jalisco and Hidalgo, Mexico. SYNONYMS: collinus, eremicoides, laceianus. COMMENTS: Revised by Schmidly (1972), who recognized three subspecies which correspond to patterns of genetic differentiation (Kilpatrick and Zimmerman, 1976). Consanguinity of included populations nevertheless suspect (see Avise et al., 1974a). See Schmidly (1974b, Mammalian Species, 49). P. boylii species group., Published as part of Guy G. Musser & Michael D. Carleton, 1993, Order Rodentia - Family Muridae, pp. 501-755 in Mammal Species of the World (2 nd Edition), Washington and London :Smithsonian Institution Press on page 735, DOI: 10.5281/zenodo.7353098, {"references":["Schmidly, D. J. 1972. Geographic variation in the white-ankled mouse, Peromyscus pectoralis. Southwestern Naturalist, 17: 113 - 138.","Kilpatrick, C. W., and E. G. Zimmerman. 1976. Biochemical variation and systematics of Peromyscus pectoralis. Journal of Mammalogy, 57: 506 - 522.","Avise, J. C., M. H. Smith, and R. K. Selander. 1974 a. Biochemical polymorphism and systematics in the genus Peromyscus. VI. The boylii species group. Journal of Mammalogy, 55: 751 - 763.","Schmidly, D. J. 1974 b. Peromyscus pectoralis. Mammalian Species, 49: 1 - 3."]}

Habitat discrimination between sympatric populations of Peromyscus attwateri and P. pectoralis was examined through live trapping, observations of escape cover, and fluorescent tracking. Discriminant-function analysis of live-trapping data defined the position of each species along a habitat gradient ranging from sloping limestone ledges with leaf litter under a live oak ( Quercus fusiformis ) canopy to more open grassy areas with scattered rocks and young mesquite ( Prosopis glandulosa ). P. attwateri was a generalist using the full range of available microhabitats. P. pectoralis specialized on areas of limestone ledges and leaf litter, and its microhabitat niche was included entirely within that of P. attwateri . Results of analysis of escape cover and fluorescent tracking for P. pectoralis confirmed the association of this species with limestone ledges. Both discriminant-function analysis and fluorescent tracking indicated that immature P. pectoralis used marginal habitats in addition to limestone ledges, therefore had a broader microhabitat niche than adults. Observation of escape cover and tracking revealed that on the study site, P. attwateri is at least semiarboreal and travels primarily in trees.

The genetic structure of 21 populations of P. pectoralis has been analyzed through electrophoretically demonstrable variation in proteins encoded by 17 to 21 structural loci. A wide range in levels of heterozygosity, 0.0 to 0.178, with a mean of 0.05, and levels of genetic similarity, 0.691 to 0.991, with a mean of 0.829, were exhibited among populations of P. pectoralis . This variation in levels of heterozygosity and genetic similarity is thought to be the result of colonization and, hence, genetic contribution from populations from three Pleistocene refugia with differentiated gene pools. With the removal of the primary isolation barriers, gene exchange between populations derived from different refugia have produced populations with high levels of heterozygosity. Because individual populations of P. pectoralis have received their genetic makeup from one to three different gene pools, they exhibit lower levels of genetic similarity than observed among most conspecific populations of this genus.

Horizontal starch gel electrophoresis revealed five hemoglobin phenotypes in natural populations of the encinal mouse, Peromyscus pectoralis, from northeastern Mexico. Populations of the encinal mouse from Texas, Oklahoma, and northwestern and north central Mexico were monomorphic for multiple-band phenotypes. Analysis of the hemoglobin polymorphism indicates that two loci control this variation.

Two species of Euschoengastia described are: E. fronterizae, new species, from Sierra Fronteriza Range, 40 km SE Boquillas del Carmen, Coahuila, Mexico, off Peromyscus difficilis and, E. chisosensis, new species, from Pine Can- yon, Big Bend National Park, Brewster County, Texas, off Peromyscus pectoralis. 1Studies upon which this paper is based were supported by the United States Public Health Service Research Grant AI03407, to California State University, Long Beach, Richard B. Loomis, Principal Investigator.

(5000 ft). The bregmatic bone, located at the anterior fontanelle at the junction of the coronal and sagittal sutures, is kite shaped, and is 2.3 mm long and 1.6 mm wide (Fig. 1). I would like to thank Dr. E. Lendell Cockrum of the University of Arizona for bringing this specimen to my attention and for his contagious enthusiasm, and Dr. D. I. Rasmussen for critically reading the manuscript.-Loy T. Merkle, Department of Zoology, Arizona State University, Tempe, Arizona 85281.