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Reithrodontomys albilabris Merriam, 1901 Type locality. “ Cerro San Felipe, Oaxaca, Mexico (altitude 10,000 ft.)”. Synonym. Reithrodontomys microdon albilabris Merriam, 1901:549. Type locality: see above. Distribution. Oaxacan Highlands. Known range (in addition to type locality) included Cerro Zempoaltepec, Vista Hermosa, Llano de las Flores, Cerro Pelón (Hall 1981), and Ixtepeji (this study), Mexico. Remarks. Reithrodontomys albilabris comprises the specimens representing haplogroup IV, with the exception of the individual CMC 1627. Information on type material and morphological characteristics is available in Merriam (1901) and Howell (1914)., Published as part of Martínez-Borrego, Daily, Arellano, Elizabeth, González-Cózatl, Francisco X, Castro-Arellano, Ivan, León-Paniagua, Livia & Rogers, Duke S, 2022, Molecular systematics of the Reithrodontomys tenuirostris group (Rodentia: Cricetidae) highlighting the Reithrodontomys microdon species complex, pp. 29-44 in Journal of Mammalogy 103 (1) on page 41, DOI: 10.1093/jmammal/gyab133, http://zenodo.org/record/7832553, {"references":["Merriam C. H. 1901. Descriptions of 23 new harvest mice (genus Reithrodontomys). Proceedings of the Washington Academy of Sciences 3: 547 - 558.","Hall E. R. 1981. The mammals of North America. 2 nd ed. Vol. 2. Hoboken, New Jersey: Wiley.","Howell A. H. 1914. Revision of the American harvest mice (Genus Reithrodontomys). North American Fauna 36: 1 - 97."]}

Reithrodontomys microdon Merriam, 1901 Type locality. “ Todos Santos, Guatemala (altitude 10,000 ft.)”. Synonym. Reithrodontomys microdon microdon Merriam, 1901:548. Type locality: see above. Distribution. Highlands of Guatemala (Howell 1914), and the extreme southern portion of Mexico (Hooper 1952). This species is distributed from the highlands of central and southern Chiapas in Mexico to the southwestern region of Guatemala. Remarks. For additional information on type material, cranial measurements, morphological characteristics, habitat, and comparisons with other species of the subgenus Aporodon, see Hooper (1952:170)., Published as part of Martínez-Borrego, Daily, Arellano, Elizabeth, González-Cózatl, Francisco X, Castro-Arellano, Ivan, León-Paniagua, Livia & Rogers, Duke S, 2022, Molecular systematics of the Reithrodontomys tenuirostris group (Rodentia: Cricetidae) highlighting the Reithrodontomys microdon species complex, pp. 29-44 in Journal of Mammalogy 103 (1) on page 41, DOI: 10.1093/jmammal/gyab133, http://zenodo.org/record/7832553, {"references":["Merriam C. H. 1901. Descriptions of 23 new harvest mice (genus Reithrodontomys). Proceedings of the Washington Academy of Sciences 3: 547 - 558.","Howell A. H. 1914. Revision of the American harvest mice (Genus Reithrodontomys). North American Fauna 36: 1 - 97.","Hooper E. T. 1952. A systematic review of harvest mice (Genus Reithrodontomys) of Latin America. Miscellaneous Publications of the Museum of Zoology, University of Michigan 77: 1 - 255."]}

Two cricetids and three arvicolines are added to the Fiene local fauna (Irvingtonian) of north-central Kansas. Cricetids include the harvest mouse, Reithrodontomys moorei and grasshopper mouse, Onychomys sp. Arvicolines include the muskrat, Ondatra annectens, red-backed vole, Myodes gapperi, and bog lemming, Mictomys kansasensis. The latter two; taxa are extralimital and indicate cooler and wetter summers than at present in the area. Likewise, the record of Myodes represents the earliest occurrence of the taxon on the central Plains. The rarity of Onychomys relative to the previously reported abundant microtids in the Fiene local fauna indicates that the transition from a granivorous diet in the Blancan to a primarily insectivorous diet it has today was completed during Irvingtonian II.

The current documented Reithrodontomys fulvescens (Fulvous Harvest Mouse) distribution includes western Mississippi. Here, we report new geographic distribution records in east-central Mississippi. We conducted live-trapping in Kemper County, MS, during the summers of 2011–2015, and captured both Fulvous Harvest Mice and Reithrodontomys humulis (Eastern Harvest Mouse). We compared measurements from captured Fulvous and Eastern Harvest Mice to verify presence of both species. Our results showed 2 separate clusters of measurements, independent of our species assignment in the field, and the clusters were significantly different (P < 0.01). It is unclear whether these new records represent a range expansion or new information about the species' historical distribution.

Copemyodon ecuadorensis was described as a non-sigmodontine extinct cricetid from two rich fossiliferous localities in northern Ecuador. It was hypothesized as being related to both the fossil genus Copemys and the living Peromyscus and, as such, is an example of an independent "copemyine-neotomine" attempt to colonize South America. Here, we re-study the holotype of C. ecuadorensis concluding that it cannot be separated from Reithrodontomys (Cricetidae, Neotominae) at a generic level. Copemyodon constitutes a junior synonym of Reithrodontomys. There are recent populations of Reithrodontomys in Ecuador and most likely it comprises several species. In this context, seems convenient to retain ecuadorensis as a species of Reithrodontomys until an appropriate revision of this genus is performed, although we identify morphological similarities between Reithrodontomys ecuadorensis and the nominal form Reithrodontomys soederstroemi. Fil: Moreno, Pablo. Museo Ecuatoriano de Ciencias Naturales. Instituto Nacional de Biodiversidad; Ecuador Fil: Román, José Luis. Escuela Politécnica Nacional; Ecuador Fil: Brito, Jorge. Museo Ecuatoriano de Ciencias Naturales. Instituto Nacional de Biodiversidad; Ecuador Fil: Pardiñas, Ulises Francisco J.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; Argentina

Eighty-six specimens representing 7 species of rodents from 9 localities in the state Zacatecas were examined for helminths. Only 5 host species were found to harbor at least 1 species: Chaetodipus sp., Dipodomys merriami atronasus, Neotoma mexicana, Otospermophilus variegatus, and Peromyscus sp.; in contrast Mus musculus and Reithrodontomys sp., were not parasitized. Three species of cestodes (Catenotaeniidae gen. sp., Hymenolepis sp., and Raillietina sp.) and 7 nematodes (Gongylonema sp., Heteromyoxyuris longejector, Lamotheoxyuris cf. ackerti, Mastophorus dipodomis, Rauschtineria sp., Pterygodermatites dipodomis, and Trichuris dipodomis) were recorded. The intestine is the most parasitized (7 taxa) and trematodes were not found. The highest species richness was recorded in D. merriami atronasus from Rancho La Barranca (6 taxa), which also had the most sampling effort. H. longejector in Chaetodipus sp. from El Gordillo, showed the greatest mean abundance, and mean intensity values, followed by Rauschtineria sp. in O. variegatus from Morelos-Zacatecas Road. All species are new locality records, 14 new host records, and 2 taxa recorded for the first time in Mexico: Rauschtineria sp. and M. dipodomis. This is the first study of helminth parasites of rodents from Zacatecas.

Terminos Lagoon area is a highly important economic and biological area, and one of the most important fresh water reservoirs in Mesoamerica. This area has been affected by human activities such as the disposal of pollutants, including pesticides that cause damage among wildlife. Our research evaluated the exposition of three wild rodent species Oryzomys couesi, Peromyscus leucopus, and Reithrodontomys gracilis to organochlorine and anticholinergic pesticides in nine localities of Terminos Lagoon. We collected samples of brain, skeletal muscle, and liver to evaluate organochlorine and anticholinergic pesticides exposure. We measure acetylcholinesterase (AChE) activity as anticholinergic pesticide exposure sign. We found significant differences in acetylcholinesterase activity among localities in brain for two species O. couesi and R. gracilis , but not for skeletal muscle tissue. We found 20 organochlorine compounds in rodent´s liver of which only lindane, aldrine and heptachlor were in amounts suggesting a recent exposure. The AChE inhibition is not enough evidence for anticholinergic pesticide exposure. Recent organochlorine pesticides application and exposition was detected, but sources are unknown, probably atmospheric deposition. Rodent exposure to pesticides could affect negatively its population dynamic. This detrimental effects can reach higher trophic levels because predators biomagnifies some of these compounds.

Concerns over climate change and finite fossil fuels have generated interest in biofuels. Switchgrass (Panicum virgatum), a biofuel feedstock, was planted in intensively managed loblolly pine (Pinus taeda) stands to investigate sustainability of this system for producing an alternative energy source. We hypothesized that changes in understory habitat conditions caused by intercropping switchgrass in pine stands would affect rodent population and community dynamics within three years. Therefore, we assessed effects of three treatments (control pine, switchgrass intercropped in pine, and switchgrass monocrop) on rodent population (abundance, survival, and recruitment) and community (diversity, richness, evenness, and community assemblages) measures. We conducted vegetation surveys and live-trapping during 2013–2015 summers in Kemper County, Mississippi, USA. We conducted 6 trapping sessions each summer (n = 14,112 trap nights per year) and captured 1,733 cotton rats (Sigmodon hispidus), 102 Oryzomys palustris, 31 Mus musculus, 28 Reithrodontomys fulvescens, 22 Reithrodontomys humulis, 20 Peromyscus leucopus, 9 Microtus pinetorum, 9 Peromyscus gossypinus, and 2 Neotoma floridana. We found greater cotton rat abundance and lower recruitment in monocrop versus control plots. Rodent diversity was lower in monocrop than control plots. Intercropped plots had intermediate levels of cotton rat abundance and recruitment, and rodent diversity. More dispersal may have occurred in monocrop plots because of high population abundance and limited habitat availability. Cotton rat survival and rodent community assemblage were similar among treatments but differed among years. Although rodents responded negatively to monocrop plots, our results suggested intercropped plots would be an appropriate management practice in pine plantations to produce biofuel feedstocks while maintaining rodent diversity.

We conducted a survey of rodents and ticks in Brazos County in east-central Texas to learn more about native fauna that may be involved in enzootic transmission of pathogens that can cause tick-borne diseases in this region. Our objectives were to describe the species richness and seasonal activity of rodents, as well as to document their infestation with ticks over time. We captured 5 rodent species over the course of 19 months: Sigmodon hispidus (Hispid Cotton Rat), Reithrodontomys fulvescens (Fulvous Harvest Mouse), Peromyscus leucopus (White-footed Mouse), Peromyscus gossypinus (Cotton Mouse), and Baiomys taylori (Northern Pygmy Mouse). We observed a large increase in Hispid Cotton Rat capture success in the fall of 2013, reflecting a characteristic population boom periodically exhibited by this species. Overall tick-infestation prevalence of rodents was low (2.3%), and was comprised of juvenile ticks of 2 species—Amblyomma maculatum (Gulf Coast Tick) and Ixodes scapularis (Blacklegged Tick)....

Reithrodontomys megalotis and R. montanus, two species of harvest mouse that co-occur at low elevations of the southeastern Rockies and western Great Plains, are notoriously difficult to distinguish both externally and cranially, particularly for juveniles. Three external characteristics and 14 cranial measurements were used in discriminate function analyses (DFA) to detect the most robust measurements for species identification. Using 151 and 66 specimens of R. megalotis and R. montanus, respectively, from Colorado, we constructed DFA models for all specimens combined and segregated into four age classes by tooth wear. Due to substantial overlap in measurements, DFA models could not reliably predict species identity based on external or cranial characteristics alone, whereas models including all characteristics were more reliable. The most reliable DFA models were those for each age class (juvenile, subadult, adult, and old adult) using all external and cranial measurements. With various DFA mod...

222. Cozumel Harvest Mouse Reithrodontomys spectabilis French: Souris-moissonneuse de Cozumel / German: Cozumel-Erntemaus / Spanish: Raton espiguero de Cozumel Other common names: Cozumel Island Harvest Mouse Taxonomy. Reithrodontomys spectabilis |. K. Jones & Lawlor, 1965, 2-5 mi (= 4 km) north of San Miguel, Isla Cozumel, Quintana Roo, Mexico. Reithrodontomys spectabilis 1s in subgenus Aporodon. Monotypic. Distribution. Cozumel I, off Yucatan Peninsula, SE Mexico. Descriptive notes. Head-body 84-89 mm, tail 121-132 mm, hindfoot 20-22 mm; weight 18-21 g. The Cozumel Harvest Mouse is one of the largest species of Reithrodontomys. Dorsum is brownish ocher, and sides are brighter in color. Venter is grayish white, with pinkish buff pectoral spot. Tail is slightly darker above than below, longer than head-body length, and scantily haired. The Cozumel Harvest Mouse is similar to the Slender Harvest Mouse (R. gracilis) and the Mexican Harvest Mouse (R. mexicanus); however,it is much bigger and darker and has more robust skull, and tail exceeds almost 34% of head-body length. Habitat. Dense, secondary vegetation (i.e. vine covered habitat adjacent to a forested area) and mature, deciduous forests. Food and Feeding. No information. Breeding. Juveniles subadults, and lactating females have been caught in August;at the same time, adult scrotal males with testicles of 9-1 mm, 13 mm, and 14 mm in length were collected. Activity patterns. The Cozumel Harvest Mouse is nocturnal and might be arboreal. Movements, Home range and Social organization. No information. Status and Conservation. Classified as Critically Endangered on The IUCN Red List. Bibliography. Engstrom et al. (1989), Hooper (1952a), Jones, J. K. (1982), Jones, J. K. & Lawlor (1965), Jones, J. K. et al. (1974), Tellez-Girén & Sanchez (2014c)., 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 pages 368-369, DOI: 10.5281/zenodo.6707142

219. Slender Harvest Mouse Reithrodontomys gracilis French: Souris-moissonneuse gracile / German: Zierliche Erntemaus / Spanish: Raton espiguero esbelto Taxonomy. Reithrodontomys mexicanus gracilis J. A. Allen & F. M. Chapman, 1897, Chichén-Itza, Yucatan, Mexico. Reithrodontomys gracilis is in subgenus Aporodon. Four subspecies recognized. Subspecies and Distribution. R. g. gracilis J. A. Allen & F. M. Chapman, 1897 — Yucatan Peninsula (SE Mexico, Belize, and N Guatemala). R.g.anthony:Goodwin,1932—CGuatemala,SWHonduras,andmostofElSalvador. R.g.harrisiGoodwin,1945—fromextremeSHondurasStoNWCostaRica. R.g.insularisJ.K.Jones,1964—knownonlyfromIsladelCarmen,CampecheState,SEMexico. R. g. pacificus Goodwin, 1932 — Pacific coastal area of SE Mexico (Chiapas State), S Guatemala, and SW El Salvador. Descriptive notes. Head—body ¢.76-78 mm, tail 87-107 mm, ear 13-16 mm, hindfoot 17-20 mm; weight 10-11 g. The Slender Harvest Mouse is small, with slender, scantily haired, bicolored tail, 97-155% of head-body length. Dorsal pelage is short, cinnamon-pink to shinny ocherous brown, and grizzled in appearance. Venter is white to bright orange-cinnamon. Soles and backs of feet are generally white but can be dusky. Ears are darker than body and sparsely haired. Habitat. Tropical deciduous and pine (Pinus, Pinaceae) forests, perennial forests, thorn forests, xeric forests, and coconut and coffee plantations from sea level to elevations of 1370 m. Food and Feeding. No information. Breeding. Breeding season can extend from the beginning of winter through midautumn. Pregnant females have been captured in the Yucatan and del Carmen Islands in July-August and scrotal males in April, June, and July. In Central America, females with embryos have been collected in March, June, and July. Activity patterns. The Slender Harvest Mouse is presumably nocturnal. Movements, Home range and Social organization. No information. Status and Conservation. Classified as Least Concern on The IUCN Red List. Bibliography. Allen & Chapman (1897b), Anderson & Jones (1960), Burt & Stirton (1961), Goodwin (1932b, 1945, 1946), Hall (1981), Hooper (1952a), Jones (1964), Jones & Genoways (1970), Sanchez (1993), Téllez & Sanchez (2014a), Young & Jones (1984)., 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 368, DOI: 10.5281/zenodo.6707142

227. Costa Rican Harvest Mouse Reithrodontomys cherrii French: Souris-moissonneuse de Cherrie / German: Costa-Rica-Erntemaus / Spanish: Ratén espiguero de Costa Rica Taxonomy. Heperomys (Vesperimus) cherrii J. A. Allen, 1891, San José, Costa Rica. Reithrodontomys cherrii was considered a subspecies of R. mexicanus and elevated to species status in 2005. Reithrodontomys cherrii is in subgenus Aporodon. Monotypic. Distribution. C Costa Rica. Descriptive notes. Head—body 67-85 mm, tail 101-117 mm, ear 14-18 mm, hindfoot 17-20 mm. No specific data are available for body weight. The Costa Rican Harvest Mouse is one of the largest and most brilliantly colored species of Reithrodontomys. Dorsum and sides are bright orange (zinc orange or ocherous orange). Braincase is deep and strongly convex, and toothrow is long. Compared with the Short-nosed Harvest Mouse (R. brevirostris), the Costa Rican Harvest Mouse has a relatively short tail. Habitat. Montane regions of central Costa Rica, including Cordillera Central and Cordillera de Talamanca, at elevations of 913-2134 m. Food and Feeding. No information. Breeding. No information. Activity patterns. No information. Movements, Home range and Social organization. No information. Status and Conservation. Not assessed on The [UCN Red List. Given relatively restricted distribution and lack of biological knowledge, the Costa Rican Harvest Mouse should be carefully monitored. Bibliography. Allen (1891a), Arellano et al. (2005), Gardner & Carleton (2009), Hooper (1952a)., 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 pages 369-370, DOI: 10.5281/zenodo.6707142

218. Darien Harvest Mouse Reithrodontomys darienensis French: Souris-moissonneuse du Darien / German: Darien-Erntemaus / Spanish: Raton espiguero de Darién Taxonomy. Reithrodontomys darienensis Pearson, 1939, upper Rio Tuyra, Santa Cruz de Cana, 2000 ft. (= 610 m), upper Rio Tuyra, Darién, Panama. Reithrodontomys darienensis is in subgenus Aporodon. Monotypic. Distribution. Restricted to E Panama. Descriptive notes. Head-body c.62-65 mm, tail 100-112 mm, ear 14-15 mm, hindfoot 17-19 mm; weight 10 g. The Darien Har vest Mouse is medium-sized. Dorsum is pale brown, with peppered or streaked pattern. Venter varies from white to orangecinnamon. Tail is long compared to that of the Slender Harvest Mouse (R. gracilis). Rastrum and braincase are shorter than in the Slender Harvest Mouse. Habitat. Lowland tropical deciduous forests with dense stands of oaks (Quercus, Fagaceae) interspersed with shrubs and grasses up to elevations of ¢.900 m. Food and Feeding. No information. Breeding. No information. Activity patterns. The Darien Harvest Mouse is presumably nocturnal. Movements, Home range and Social organization. No information. Status and Conservation. Classified as Least Concern on The IUCN Red List. Bibliography. Hall (1981), Hooper (1952a), Pearson (1939)., 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 pages 367-368, DOI: 10.5281/zenodo.6707142

226. Small-toothed Harvest Mouse Reithrodontomys microdon French: Souris-moissonneuse a petites dents / German: Kleinzahn-Erntemaus / Spanish: Raton espiguero de dientes pequenos Taxonomy. Reithrodontomys microdon Merriam, 1901, “Todos Santos, Guatemala (altitude 10,000 ft. [= 3048 m]).” Reithrodontomys microdon is in subgenus Aporodon. Three subspecies recognized. Subspecies and Distribution. R.m.microdonMerriam,1901—fromCChiapasState(SEMexico)StoCGuatemala. R.m.albilabrisMerriam,1901—NCOaxacaState(SMexico). R. m. wagner Hooper, 1950 — from C Michoacan E to México states (C Mexico). Descriptive notes. Head-body c.68-70 mm, tail 101-117 mm, ear 16-19 mm, hindfoot 19-21 mm; weight 20 g. The Small-toothed Harvest Mouse is mediumto large-sized. Dorsal pelage is thick and cinnamon-orange to dark reddish brown. Venter is whitish to bright orangish or pinkish cinnamon. Eyes have distinct black rings. Hindfeet are blackish, sometimes rimmed with white. Tail is unicolored and blackish. Habitat. Hillsides and canyons in pine-fir and pine-oak forests at elevations of 2225— 3050 m. Small-toothed Harvest Mice prefer typical cloud forest, montane grassland and shrubland (zacatonal), or volcanic habitat where undergrowth consists of ferns, mosses, and shrubs. Food and Feeding. The Small-toothed Harvest Mouse feeds on seeds, grains, grasses, and other vegetation. Breeding. No information. Activity patterns. The Small-toothed Harvest Mouse is the most arboreal and specialized species of Reithrodontomys. It is presumably nocturnal. Movements, Home range and Social organization. No information. Status and Conservation. Classified as Least Concern on The IUCN Red List. Because populations of Small-toothed Harvest Mice are supposedly declining, further investigation is needed to accurately assess its conservation status. Bibliography. Hall (1981), Hooper (1950, 1952a), Merriam (1901b), M{idespacher & Gaona (2014), Sanchez (1993)., 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 369, DOI: 10.5281/zenodo.6707142

240. Zacatecan Harvest Mouse Reithrodontomys zacatecae French: Souris-moissonneuse du Zacatecas / German: Zacateca-Erntemaus / Spanish: Raton espiguero de Zacatecas Other common names: Zacatecas Harvest Mouse Taxonomy. Reithrodontomys megalotis zacatecae Merriam, 1901, Sierra de Valparaiso, Zacatecus, Mexico. Reithrodontomys zacatecae was originally described as a subspecies of R. megalotis. In 1952, it was proposed that it could represent a valid species, a contention supported by chromosomal studies and DNA sequences. Reithrodontomys zacatecae is in subgenus Reithrodontomys. Monotypic. Distribution. Sierra Madre Occidental from W Chihuahua S to WC Michoacan states (W Mexico). Descriptive notes. Head—body 61-70 mm, tail 67-87 mm, ear 13-18 mm, hindfoot 17-20 mm; weight 9-13 g. Dorsum of the Zacatecan Harvest Mouse is reddish brown, with dark stripe down mid-dorsal line. Pelage is grizzled similar to the Western Harvest Mouse (R. megalotis) but more intense. Venteris paler than dorsum. Habitat. Open grasslands in pine-oak forests at elevations of 1828-2590 m. The Zacatecan Harvest Mouse occurs at higher elevations than the Western Harvest Mouse, although they are often parapatric. Food and Feeding. Probably similar to the Western Harvest Mouse. Breeding. No information, but the Zacatecan Harvest Mouse is probably similar to the Western Harvest Mouse. Activity patterns. Probably similar to the Western Harvest Mouse. Movements, Home range and Social organization. Probably similar to the Western Harvest Mouse. Status and Conservation. Classified as Least Concern on The IUCN Red List. Bibliography. Anderson (1972), Baker & Greer (1962), Bell et al. (2001), Hood et al. (1984), Hooper (1952a), Matson & Baker (1986), Merriam (1901b), Sanchez (2014e)., 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 373, DOI: 10.5281/zenodo.6707142

221. Nicaraguan Harvest Mouse Reithrodontomys paradoxus French: Souris-moissonneuse du Nicaragua / German: Nicaragua-Erntemaus / Spanish: Raton espiguero de Nicaragua Taxonomy. Reithrodontomys paradoxus J. K. Jones & Genoways, 1970, 3 mi (= 5 km) NNW Diriamba, ¢. 660 m, Carazo Dept., Nicaragua. Reithrodontomys paradoxus is in subgenus Aporodon. Monotypic. Distribution. Known only from isolated records in SW Nicaragua and WC Costa Rica. Descriptive notes. Head-body 71-72, tail 96-101 mm, ear 13 mm, hindfoot 18 mm; for two individuals from the type locality. No specific data are available for body weight. The Nicaraguan Harvest Mouse is small; dorsum is buffy brown, infused with ocherous hairs; sides are ocherous; and venter is white. Hindfoot has characteristic wedgeshaped dusky area that extends to bases of toes. Tail is long relative to head-body length. Skull resembles that of the Short-nosed Harvest Mouse (R. brevirostris), but it is longer and less inflated. Habitat. Foothills in south-western Nicaragua and west-central Costa Rica. Food and Feeding. No information. Breeding. No information. Activity patterns. The Nicaraguan Harvest Mouse is presumably nocturnal. Movements, Home range and Social organization. No information. Status and Conservation. Classified as Data Deficient on The IUCN Red List. Bibliography. Hooper (1952a), Jones & Baldassarre (1982), Jones & Genoways (1970)., 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 368, DOI: 10.5281/zenodo.6707142

238. Salt-marsh Harvest Mouse Reithrodontomys raviventris French: Souris-moissonneuse a ventre gris / German: Salzsumpf-Ernttemaus / Spanish: Raton espiguero de marisma Taxonomy. Reithrodontomys raviventris Dixon, 1908, “Redwood City, San Mateo County, Calif[ornia].,” USA. Reithrodontomys raviventris is in subgenus Reithrodontomys. Two subspecies recognized. Subspecies and Distribution. R.r.raviventrisDixon,1908—SportionofSanFranciscoBay,California(USA). R. r. halicoetes Dixon, 1909 — N portion of San Francisco Bay, California (USA). Descriptive notes. Head—body 62-80 mm, tail 56-95 mm, hindfoot 20-22 mm; weight 8-15 g. Dorsum of the Saltmarsh Harvest Mouse has a mix of long,thick, blackish and cinnamon hairs. Tawny lateralstrip is present. Venter is white to cinnamon. Ears are blackish, with tuft of ocherous hair at bases. Tail is about as long as head-body and indistinctly bicolored. Habitat. Salt and brackish marshes dominated by grasses and species of Salicornia (Amaranthaceae). Food and Feeding. The Salt-marsh Harvest Mouse reportedly eats glasswort (Salicornia) and tule (Schoenoplectus, Cyperaceae). Breeding. Reproductive activity is thought to occur in March-November. Average litter sizes are 3-7-3-9 young. Activity patterns. No information. Movements, Home range and Social organization. No information. Status and Conservation. Classified as Endangered on The IUCN Red List. Bibliography. Dixon (1908, 1909), Fisler (1965), Hooper (1952a), Shellhammer et al. (1982)., 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 372, DOI: 10.5281/zenodo.6707142

231. Fulvous Harvest Mouse Reithrodontomys fulvescens French: Souris-moissonneuse fauve / German: Gelbliche Erntemaus / Spanish: Raton espiguero leonado Taxonomy. Reithrodontomys mexicanus fulvescensJ. A. Allen, 1894, Oposura, 2000 ft (= 610 m), Sonora, Mexico. Reithrodontomys fulvescens is in subgenus Reithrodontomys. Seventeen subspecies recognized. Subspecies and Distribution. R. f fulvescens J. A. Allen, 1894 — SE Arnizona (SW USA) and NE Sonora State (NW Mexico). R.f.amoenusElliot,1905—knownonlyfromthetypelocalityinReforma,Oaxaca(SMexico). R.f.awrantiusJ.A.Allen,1895—fromSEKansasandSWMissouriSintoTexas,Louisiana,andMississippi(USA). R.f.canusBenson,1939—SWTexas(USA)andNCMexico. R.f.chiapensisA.H.Howell,1914—fromChiapasState(SEMexico)SEtoHonduras. R.f.difficilisMerriam,1901—WCVeracruz,EHidalgo,andPueblastates(ECMexico). R.f.griseoflavusMerriam,1901—CMexico. R.f.helvolusMerriam,1901—EGuerreroandOaxacastates(SMexico). R.f.infernatisHooper,1950—SedgeofPueblaandNOaxacastates(SMexico). R.f.intermediusJ.A.Allen,1895—STexas(USA)andNEMexico. R.f.laceyi].A.Allen,1896—CTexas(SUSA). R. f. menidionalis S. Anderson &J. K. Jones, 1960 — W Nicaragua. R.f.mustelinusA.H.Howell,1914—fromSMichoacanSEtoSOaxaca(SMexico). R.f.nelsoniA.H.Howell,1914—ColimaandWedgeofJalisco(WMexico). R.f.tenuis].A.Allen,1899—SSonoraandChihuahuaStoNayaritstates(WMexico). R.f.toltecusMerriam,1901—portionsofQuerétaro,Hidalgo,México,andMichoacanstates(ECMexico). R. f. tropicalis Davis, 1944 — from S Tamaulipas S to C Veracruz states (E Mexico). Descriptive notes. Head—body 62-84 mm,tail 72-116 mm, ear 11-17 mm, hindfoot 16-22 mm; weight 8-12 g. The Fulvous Harvest Mouse is small, with relatively long tail. Dorsum has a mix of reddish brown and black hairs, producing grizzled or salt-andpepper appearance. Venter is pale to whitish. Pelage along sides is often ocherous. Tail is generally paler underneath and dark above. Rostrum is robust, and braincase is elongated. Habitat. Moderately dry forested areas of pine (Pinus, Pinaceae) and oak (Quercus, Fagaceae) or mesquite (Prosopis, Fabaceae), deciduous forests, thorn scrublands, grasslands, xeric shrublands, and less commonly tropical forests from sea level to elevations of ¢.2600 m. Generally, Fulvous Harvest Mice occupy ecotones of grasslands and rocky outcrops with patches of scrub or wooded areas that provide protection. Food and Feeding. The Fulvous Harvest Mouse is omnivorous. During rainy season, diets can be almost 90% invertebrates, but during remainder of the year, seeds are the most significant parts of diets. Breeding. Fulvous Harvest Mice can reproduce throughout the year. Gestation is ¢.22 days, and generally at least two litters are produced annually. Litters have 2-8 young (average three). They construct spherical nests of grass, placed several inches below soil surface. Young are altricial at birth and are weaned at c.15 days old. Activity patterns. The Fulvous Harvest Mouse is semi-arboreal and thoughtto be strictly nocturnal. Movements, Home range and Social organization. In central Mexico, average density of the Fulvous Harvest Mouse is 0-6 ind/ha. Status and Conservation. Classified as Least Concern on The IUCN Red List. Bibliography. Allen (1894b, 1895a, 1896, 1899a), Anderson & Jones (1960), Benson (1939), Cameron et al. (1979), Ceballos & Miranda (2000), Chavez (1993), Davis, W.B. (1944), Elliot (1905), Hall (1981), Hooper (1950, 1952a), Howell (1914), Kincaid (1975), Merriam (1901b), Packard (1968), Petersen (1978), Sanchez (1993), Sanchez & Oliva (2014a), Spencer & Cameron (1982), Svihla (1930)., 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 pages 370-371, DOI: 10.5281/zenodo.6707142

217. Short-nosed Harvest Mouse Reithrodontomys brevirostris French: Souris-moissonneuse a nez court / German: Kurznasen-Erntemaus / Spanish: Ratén espiguero de hocico corto Taxonomy. Reithrodontomys brevirostris Goodwin, 1943, canyons above Villa Quesada, 5000 ft. (= 1524 m), Alajuela Province, Costa Rica. Reithrodontomys mexicanus potrerograndei is recognized as a subjective junior synonym of R. brevirostris. Reithrodontomys brevirostris is in subgenus Aporodon. Two subspecies recognized. Subspecies and Distribution. R.b.brevirostrisGoodwin,1943—knownonlyfromtwodisjunctareasintheCordilleraCentralofNC&SECostaRica. R. b. nicaraguae]. K. Jones & Genoways, 1970 — known only from the type locality and surrounding regions of the Cordillera Dariense in NC Nicaragua. Descriptive notes. Head-body 62-69 mm, tail 97-114 mm, ear 14-16 mm, hindfoot 16-19 mm; weight 11-16 g. The Short-nosed Harvest Mouse is small to medium-sized, with dense, long, and lax pelage characteristic of some species in subgenus Aporodon. Dorsum is dark, with ocherous color along sides; venter is lighter. Hindfoot has characteristic wedge-shaped dusky area that extends to bases of toes. Tail is long relative to head-body length. Skull is small, and rostrum is short and narrow. Habitat. Cloud forest areas of the Cordillera Central in central Costa Rica and Cordillera Dariensis in north-central Nicaragua. In both areas, Short-nosed Harvest Mice were collected in areas cleared for cultivation of coffee plants, near bases of broadleafed native trees. They also were collected in deep rocky canyons. Food and Feeding. No information. Breeding. Reproductively active males were collected in June-July, and pregnantfemales were captured in June. Activity patterns. The Short-nosed Harvest Mouse is presumably nocturnal. Movements, Home range and Social organization. No information. Status and Conservation. Classified as Least Concern on The IUCN Red Lust. Bibliography. Gardner & Carleton (2009), Goodwin (1943, 1946), Hooper (1952a), Jones & Baldassarre (1982), Jones & Genoways (1970)., 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 367, DOI: 10.5281/zenodo.6707142

235. Eastern Harvest Mouse Reithrodontomys humulis French: Souris-moissonneuse de I'Est / German: Ostliche Erntemaus / Spanish: Raton espiguero oriental Taxonomy. Mus humulis Audubon & Bachman, 1841, vicinity of Charleston, Charleston County, South Carolina, USA. Reithrodontomys humulis is in subgenus Reithrodontomys. Three subspecies recognized. Subspecies and Distribution. R.h.humulisAudubon&Bachman,1841—fromextremeNEArkansas,Mississippi,andSELouisianaEtoCVirginiaandStoSCFlorida(SEUSA). R.h.merriamiJ.A.Allen,1895—EOklahoma,ETexas,WArkansas,andW&SCLouisiana(SUSA). R. h. virginianus A. H. Howell, 1940 — SW Maryland and E Virginia (E USA). Descriptive notes. Head-body 62-68 mm, tail 45-60 mm, ear 8-9 mm, hindfoot 15-17 mm; weight 7-12 g. The Eastern Harvest Mouse is among the smallest species of Reithrodontomys. Dorsum is brownish to dark brown, sometimes faintly washed with gray, and has dark mid-dorsal stripe. Sides are paler than dorsum and usually have lateral line stripe. Venter is ash-colored, with cinnamon or pinkish infusion. Tail is slender and sparsely haired. Ears are fuscous or fuscous black, and feet are grayish white. Habitat. Wooded or grassland habitats with dense understory, old fields, abandoned fields, and croplands. Food and Feeding. The Eastern Harvest Mouse eats seeds, green vegetation, and insects. Breeding. The Eastern Harvest Mouse has reproductive peaks in spring and autumn. Gestation is c.21 days, and litters have 1-8 young. Activity patterns. The Eastern Harvest Mouse is presumably nocturnal. Movements, Home range and Social organization. Mean home ranges are 905-1 m? for males and 1094-5 m* for females. Eastern Harvest Mice are not thought to be territorial. Status and Conservation. Classified as Least Concern on The IUCN Red List. Bibliography. Allen (1895a), Audubon & Bachman (1841), Cawthorn & Rose (1989), Dunaway (1968), Hooper (1952a), Howell (1914, 1940), Packard (1968), Stalling (1997)., 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 pages 371-372, DOI: 10.5281/zenodo.6707142

237. Plains Harvest Mouse Reithrodontomys montanus French: Souris-moissonneuse des plateaux / German: Steppen-Erntemaus / Spanish: Raton espiguero de llanura Taxonomy. Reithrodon montanus Baird, 1855, “vicinity of the Rocky Mountains,lat. 38°.” Restricted byJ. A. Allen in 1895 to “near the upper end of the San Luis Valley in Colorado,” USA. Reithrodontomys montanus is in subgenus Reithrodontomys. Three subspecies recognized. Subspecies and Distribution. R.m.montanusBaird,1855—SCColorado,SEArizona,WC&SNewMexico,andSWTexas(USA),andNESonora,Chihuahua,andextremeNCDurangostates(NMexico). R.m.albescensCary,1903—SEMontana,SWNorthDakota,EWyoming,W&SSouthDakota,mostofNebraska,EColorado,WKansas,extremeNENewMexico,andextremeNW&NCOklahoma(USA). R. m. griseus Bailey, 1905 — SE Nebraska, E Kansas, Oklahoma, extreme SW Missouri, extreme NW Arkansas, and Texas (USA). Descriptive notes. Head-body 55-65 mm, tail 54-65 mm, ear 13-17 mm, hindfoot 15-17 mm; weight 7-9 g. The Plains Harvest Mouse is one of the smallest species of Reithrodontomys. Dorsum is pale grayish brown, sprinkled with fulvous and black hairs. It has prominent dark mid-dorsal stripe. Venter is white. Tail is either equalto or shorter than head-body length, which is diagnostic; tail has pronounced black stripe bordered by white hairs. Habitat. Grasslands, especially in areas dominated by meadows with abundant blue gramma (Bouteloua gracilis, Poaceae) and other species of perennial grasses, riparian areas, and abandoned crop fields at elevations of 1200-1920 m (most records are near lower elevation). Food and Feeding. Plains Harvest Mice are insectivorous and herbivorous. They reportedly eat grasshoppers, grass, seeds, and fruits of cacti. Breeding. The Plains Harvest Mouse has an average of four offspring per litter (range 1-9). Gestation is 21 days. Young are altricial at birth. Oval-shaped nests (110 x 80 mm) lined with grasses and soft leaves are constructed between shrubs, under fallen logs, or between rocks. Activity patterns. The Plains Harvest Mouse is nocturnal and terrestrial. Movements, Home range and Social organization. Home ranges in Texas range between 0-23 ind/ha and 0-84 ind/ha. Densities are 1-5 ind/ha. Status and Conservation. Classified as Least Concern on The IUCN Red Lust. Bibliography. Allen (1895a), Anderson (1972), Bailey (1905), Baird (1855b), Brown (1946), Cary (1903), Davis (1974), Hall (1981), Hooper (1952a), Maxwell & Brown (1968), Moulton et al. (1981), Téllez & Sanchez (2014b), Waggoner (1975), Wilkins (1986)., 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 372, DOI: 10.5281/zenodo.6707142

223. Talamancan Harvest Mouse Reithrodontomys creper French: Souris-moissonneuse du Chiriqui / German: Talamanca-Erntemaus / Spanish: Raton espiguero de Talamanca Other common names: Chiriqui Harvest Mouse Taxonomy. Reithrodontomys creper Bangs, 1902, Volcan de Chiriqui, 11,000 ft. (= 3353 m), Chiriqui Province, Panama. Reithrodontomys creper is in subgenus Aporodon. Monotypic. Distribution. NC Costa Rica to WC Panama. Descriptive notes. Head-body 89-93 mm, tail 119-145 mm, ear 13-17 mm, hindfoot 22-25 mm. No specific data are available for body weight. The Talamancan Harvest Mouse is the largest species of Reithrodontomys. Dorsum is brownish orange, infused with black guard hairs; sides are tawny; and venter is pinkish cinnamon. Compared to the Narrow-nosed Harvest Mouse (R. tenuirostris), the Talamancan Harvest Mouse has larger skull and more robust rostrum. Habitat. Wet forested areas with grasses and fallen logs and bases of rock cliffs generally above elevations of 2290 m. The Talamancan Harvest Mouse is found throughout high-elevation regions of south-central Costa Rica and west-central Panama, especially at various volcanoes and throughout the Cordillera de Talamanca. Food and Feeding. No information. Breeding. No information. Activity patterns. The Talamancan Harvest Mouse is presumably nocturnal. Movements, Home range and Social organization. No information. Status and Conservation. Classified as Least Concern on The IUCN Red List. Bibliography. Bangs (1902), Hall (1981), Hooper (1952a)., 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 369, DOI: 10.5281/zenodo.6707142

229. Musser’s Harvest Mouse Reithrodontomys musseri French: Souris-moissonneuse de Musser / German: MusserErntemaus / Spanish: Ratén espiguero de Musser Taxonomy. Reithrodontomys musseri Gardner & Carleton, 2009, Cerro Asuncion, ca. 11,100 ft (= 3383 m), Cartago, Costa Rica; ca. 09°34°05"N, 83°44’12”W (coordinates define a place along the east side of the Panamerican Highway, just 0-4 km WNW of the peak of Cerro La Asuncion). The name musseri was assigned to a specimen formerly identified as R. rodriguezi. Reithrodontomys musseri is in subgenus Aporodon. Monotypic. Distribution. Restricted to the type locality in the Cordillera de Talamanca, C Costa Rica. Descriptive notes. Head—body 62 mm, tail 99 mm, ear 14 mm, hindfoot 19 mm. No specific data are available for body weight. Musser’s Harvest Mouse is among the smallest species of Reithrodontomys. Dorsal pelageis dark (sepia or fuscous) and slightly woolly, fading to paler and brighter color (buffy brown to ocherous) along sides. Venter is whitish pale buff, with gray basal appearance. Tail is longer than head-body length. Dentition is extremely small and delicate. Habitat. Only known from wet, cloud forest at type locality at an elevation of 3383 m. Food and Feeding. No information. Breeding. No information. Activity patterns. No information. Movements, Home range and Social organization. No information. Status and Conservation. Not assessed on The IUCN Red List. Given that Musser’s Harvest Mouse is known from only a single specimen,it could be highly endangered. Bibliography. Gardner & Carleton (2009), Hooper (1952a)., 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 370, DOI: 10.5281/zenodo.6707142

228. Chiriquian Harvest Mouse Reithrodontomys garichensis French: Souris-moissonneuse du Gariché / German: Chiriquia-Erntemaus / Spanish: Raton espiguero de Chiriqui Taxonomy. Reithrodontomys mexicanus garichensis Enders & Pearson, 1940, Rio Gariché, 5 mi (= 8 km) SW El Volcan Post Office, 3200 ft (= 975 m), Chiriqui Province, Panama. Reithrodontomys garichensis was considered a subspecies of R. mexicanus. Reithrodontomys garichensis is in subgenus Aporodon. Monotypic. Distribution. Cordillera de Talamanca of C & SE Costa Rica and W Panama. Descriptive notes. Head-body 75-79 mm, tail 110-120 mm, ear 13-16 mm, hindfoot 20-21 mm. No specific data are available for body weight. The Chiriquian Harvest Mouse is similar in size to the Costa Rican Harvest Mouse (R. cherrii) but with darker and duller dorsal pelage. Tail is longer, and hindfoot lacks bright white edge observed in the Costa Rican Harvest Mouse. Compared with the Costa Rican Harvest Mouse, the Chiriquian Harvest Mouse has a narrower, elongated rostrum. Habitat. Wet montane forests at elevations of 975-3350 m. Food and Feeding. No information. Breeding. No information. Activity patterns. The Chiriquian Harvest Mouse is presumably nocturnal. Movements, Home range and Social organization. No information. Status and Conservation. Not assessed on The IUCN Red List. Given the relatively restricted distribution and lack of biological knowledge, the Chiriquian Harvest Mouse should be carefully monitored. Bibliography. Arellano et al. (2005), Enders & Pearson (1940), Gardner & Carleton (2009), Hooper (1952a)., 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 370, DOI: 10.5281/zenodo.6707142

230. Baker’s Harvest Mouse Reithrodontomys bakeri French: Souris-moissonneuse de Baker / German: BakerErntemaus / Spanish: Raton espiguero de Baker Other common names: Baker's Small-toothed Harvest Mouse Taxonomy. Reithrodontomys bakeri Bradley et al., 2004, 4 mi (= 6- 4 km) SSW Filo de Caballo, Guerrero, Mexico. Populations now assigned to this species previously were recognized as R. microdon wagneri, but assessment of morphological and genetic characteristics showed that populations in Guerrero, Mexico, represented a new endemic species. Reithrodontomys bakeri is in subgenus Aporodon. Monotypic. Distribution. Endemic to Sierra Madre del Sur in C Guerrero State (S Mexico). Descriptive notes. Head-body 71-78 mm, tail 94-107 mm, ear 17-19 mm, hindfoot 17-19 mm; weight 20 g. Baker’s Harvest Mouse is a medium to large-sized species of Reithrodontomys. Dorsal pelage is brown to blackish at tips; however, sides and underlying pelage are tawny to orangish, giving an overall orangish appearance. Ventral pelage is white at tips and dark at bases. Feet have black stripe extending from ankles to toes. Tail is uniform gray, scantily haired at base, and more heavily haired at tip. Morphologically, Baker’s Harvest Mouse differs from the Small-toothed Harvest Mouse (R. microdon) by having slightly larger ears, longer and broader rostrum (distally), longer palate, longer molar toothrow, broader zygomatic plate, and greater breadth of mesopterygoid fossa. Habitat. Pine (Pinus, Pinaceae) and oak (Quercus, Fagaceae) habitats associated with cloud forests at elevations greater than 2150 m. Baker’s Harvest Mouse is endemic to montane regions of central Guerrero. It is currently known only from Filo de Caballo and Omiltemi, although it may occupy other montane regions in the same area. Food and Feeding. Baker’s Harvest Mouse probably eats seeds, fruits, and leaves. Breeding. No information. Activity patterns. No information. Movements, Home range and Social organization. No information. Status and Conservation. Classified as Endangered on The IUCN Red List. Baker’s Harvest Mouse has a restricted distribution, and its forest habitats are decreasing. Bibliography. Bradley, Edwards et al. (2004), Ceballos & Bradley (2014)., 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 370, DOI: 10.5281/zenodo.6707142

220. Mexican Harvest Mouse Reithrodontomys mexicanus French: Souris-moissonneuse du Mexigue / German: Mexiko-Erntemaus / Spanish: Raton espiguero de México Taxonomy. Reithrodon mexicanus Saussure, 1860, “les montagnes [= mountains] de la province de Véra-Cruz,” Mexico. Fixed by E. T. Hooper in 1952 “at Mirador, Veracuz,” Mexico. Reithrodontomys mexicanus cherrii and R. m. garichensis are now recognized as distinct species. Furthermore, R. m. potrerograndei is recognized as subjective synonym of R. brevirostris. Reithrodontomys mexicanus 1s in subgenus Aporodon. Based on molecular and morphological evidence, E. Arellano in 2015 concluded that South American subspecies are aligned with R. dariensis, not R. mexicanus, a hypothesis that makes biogeographic sense. Ten subspecies recognized. Subspecies and Distribution. R.m.mexicanusSaussure,1860—fromSTamaulipasStoOaxacastates(E&SMexico). R.m.eremicusHershkovitz,1941—ValledelChota(NEcuador). R.m.howelliGoodwin,1932—fromCChiapasState(SMexico)SEthroughGuatemalatoHonduras. R.m.lucifronsA.H.Howell,1932—SWHondurasandNWNicaragua. R.m.miller].A.Allen,1912—WColombiaandNWEcuador. R.m.ocotepequensisGoodwin,1937—WHonduras. R.m.orinusHooper,1949—SGuatemalaandElSalvador. R.m.ripariusHooper,1955—fromSWMichoacanSEtoOaxacastates(SMexico). R.m.scansorHooper,1950—SEOaxacaandNWChiapasstates(SEMexico). R. m. soederstroem: Thomas, 1898 — N Ecuador. Descriptive notes. Head-body 60-80 mm, tail 90-115 mm, ear 12-18 mm, hindfoot 17-21 mm; weight 19 g. The Mexican Harvest Mouse is a relatively large species of Reithrodontomys. Dorsum varies from tawny or yellow-brown to orange-brown and ocherous, but wide variation in pelage color occurs among subspecies. Venter varies from creamy white to light cinnamon or cinnamon orange. Tail is uniformly dark above and below. Habitat. Pine (Pinus, Pinaceae) and oak (Quercus, Fagaceae), cloud, and tropical deciduous forests at elevations of 90-1800 m. In arid areas, Mexican Harvest Mice occur in riparian habitats, especially where fig (Fiscus, Moraceae) and other trees are found. Local distribution may be limited by availabilities of shrubby cover, grasses, and other elements of herbaceous stratum. In Chiapas, Mexican Harvest Mice have been captured on flowering coral tree (Erythrina sp., Fabaceae) trees. Food and Feeding. No information. Breeding. Breeding season occurs in June-August. Litters have 3-5 young. Activity patterns. The Mexican Harvest Mouse is nocturnal and arboreal. Movements, Home range and Social organization. No information. Status and Conservation. Classified as Least Concern on The IUCN Red List. Bibliography. Arellano (2015), Arellano et al. (2005), Brito & Batallas (2014), Chavez (2012), Gardner & Carleton (2009), Goodwin (1932b, 1937 1969), Hall (1981), Hooper (1949, 1950, 1952a, 1955), Howell (1932), Jones & Genoways (1970), Moreno & Roman (2013), Sanchez (1993), Sanchez & Oliva (2014b), de Saussure (1860)., 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 368, DOI: 10.5281/zenodo.6707142

239. Sumichrast’s Harvest Mouse Reithrodontomys sumichrasti French: Souris-moissonneuse de Sumichrast / German: Sumichrast-Erntemaus / Spanish: Raton espiguero de Sumichrast Taxonomy. Reithrodon sumichrasti Saussure, 1861, “Mexicana tellus.” Restricted by E. T. Hooper in 1952 to Mirador, Veracruz. Reithrodontomys sumichrasti is in subgenus Reithrodontomys. Seven subspecies recognized. Subspecies and Distribution. R.s.sumichrastiSaussure,1861—fromQuerétaroStoOaxacastates(SCMexico). R.s.australis].A.Allen,1895—CordilleradeTalamancaofCostaRica. R.s.dorsalisMerriam,1901—ChiapasState(SEMexico)andGuatemala. R.s.luteolusA.H.Howell,1914—CGuerreroandWOaxacastates(SMexico). R.s.modestusThomas,1907—SWHonduras,extremeNElSalvador,andNWNicaragua. R. s. nerterus Merriam, 1901 — from S Jalisco E to W México states (WC Mexico). R. s. vulcanius Bangs, 1902 — known only from the type locality and surrounding areas in W Panama. Descriptive notes. Head-body 75-88 mm, tail 81-113 mm, ear 12-18 mm, hindfoot 18-21 mm; weight 12-16 g. Sumichrast’s Harvest Mouse is medium-sized. Dorsum ranges from cinnamon and orange to darker gray, depending on subspecies and level of banding on hairs. Venter is lighter and ranges from cinnamon to brown or buffy pink to cinnamon-pink. Tail is long and brown or dark brown on top and lighter underneath. Hindfeet vary from white, cinnamon, and pink to cinnamon-pink. Dark line on dorsum is characteristic of subspecies dorsalis. Habitat. Subtropical and temperate regions with grasslands, shrubby vegetation, pineoak forests, cloud forests, subtropical forests with abundant ferns and mosses, maize fields, and sugar cane and mango plantations at elevations of 800-3200 m. Sumichrast’s Harvest Mouse is typically most common in cold and wet pine-oak forests and riparian habitats. Food and Feeding. No information. Breeding. A pregnant Sumichrast’s Harvest Mouse was captured in April. Activity patterns. Sumichrast’s Harvest Mouse is presumably nocturnal. Movements, Home range and Social organization. No information. Status and Conservation. Classified as Least Concern The IUCN Red Lust. Bibliography. Allen (1895a), Baker & Phillips (1965), Baker & Womochel (1966), Bangs (1901), Burt (1961), Goodwin (1969), Hall (1981), Hall & Dalquest (1963), Heaney & Birney (1977), Hooper (1952a, 1961), Howell (1914), Merriam (1901b), Ponce-Ulloa & Llorente (1993), Ramirez-Pulido, Quijano et al. (2014), de Saussure (1861), Smith & Jones (1967), Thomas (1907b)., 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 pages 372-373, DOI: 10.5281/zenodo.6707142

236. Western Harvest Mouse Reithrodontomys megalotis French: Souris-moissonneuse de |'Ouest / German: Westliche Erntemaus / Spanish: Raton espiguero occidental Other common names: Southern Marsh Harvest Mouse Taxonomy. Reithrodon megalotis Baird, 1858, “between Janos, Sonora [Mexico] and San Luis Springs [New Mexico, USA].” Reithrodontomys megalotis is in subgenus Reithrodontomys. Fifteen subspecies recognized. Subspecies and Distribution. R.m.megalotisBaird,1858—fromextremeSCBritishColumbia(Canada)SthroughtheWthirdoftheUSAtoMichoacanState(CMexico). R.m.alticolusMerriam,1901—EGuerreroandOaxacastates(SCMexico). R.m.amolesA.H.Howell,1914—knownonlyfromthetypelocalityandsurroundingareainSierraGorda,QuerétaroState,CMexico,atanelevationofabout2285m. R.m.arizonensis].A.Allen,1895—knownonlyfromthetypelocalityinChiricahuaMts,SEArizona,USA,atanelevationofabout2440m. R.m.aztecus|].A.Allen,1893—SEUtah,SColorado,SWKansas,NEArizona,N&CNewMexico,NWTexas,andOklahomaPanhandle(USA). R.m.catalinaeElliot,1904—SantaBarbaraI,California(USA). R.m.distichlisvonBloeker,1937—smallregionofWCCalifornia(USA). R.m.dycheiJ.A.Allen,1895—fromSEAlbertaandSWSaskatchewan(Canada)EtoSWWisconsin,WCIndiana,andMissouri,andStoNEColorado,Kansas,andNEArkansas(USA). R.m.hooperiGoodwin,1954—knownonlyfromthetypelocalityandsurroundingareainWCTamaulipasState(NEMexico). R.m.limicolavonBloeker,1932—knownonlyfromthetypelocalityandsurroundingareainSWCalifornia(USA). R.m.longicaudusBaird,1858—SWWashingtonandWCalifornia(USA)andNWBajaCaliforniaState(NWMexico). R.m.peninsulaeElliot,1903—NBajaCaliforniaState(NWMexico). R.m.ravusGoldman,1939—knownonlyfromthetypelocalityandsurroundingareainNUtah(USA). R.m.santacruzaePearson,1951—SantaCruzI,California(USA). R. m. saturatusJ. A. Allen & F. M. Chapman, 1897 — from Coahuila and Nuevo Leon S to México, Morelos, Puebla, and Veracruz states (Mexico). Descriptive notes. Head-body 63-74 mm, tail 55-96 mm, ear 10-16 mm, hindfoot 14-20 mm; weight 8-13 g. The Western Harvest Mouse is small. Dorsum is light brown or grayish to blackish at base, with buffy tips. Venter is dark buff to white, often with buffy pectoral spot. Tail is bicolored and equal to head-body length. Habitat. Widespread in various habitats ranging from pine-oak forests to natural grasslands at elevations 76 m below sea level in Death Valley, California (USA) to 4000 m. In forested areas, Western Harvest Mice are typically found in areas covered with grass, weeds, and shrubs. Food and Feeding. The Western Harvest Mouse is mainly granivorous but occasionally eats plant material and invertebrates. Breeding. Males tend to be polygamous. Offspring are born in spherical nests ¢.12 cm in diameter, constructed with grass and other vegetation. Gestation is c.5 days. Litters have 1-9 young. Young are altricial birth and are weaned after c.25 days. Activity patterns. The Western Harvest Mouse is nocturnal and mainly terrestrial. Movements, Home range and Social organization. Home ranges are large at ¢.3500 m?. Generally, densities are 4-11 ind/ha but in exceptionally good years can increase to 60 ind/ha. In central Mexico, densities of 0-7-15-8 ind/ha have been reported in open areas and fields. Status and Conservation. Classified as Least Concern on The IUCN Red List. Bibliography. Allen (1893, 1895a), Allen & Chapman (1897a), Baird (1858), Bell et al. (2001), von Bloeker (1932, 1937), Ceballos & Galindo (1984), Elliot (1903b, 1904a), Fa et al. (1990), Fisler (1965), Goldman (1939), Goodwin (1954), Gray (1943), Hall (1981), Hood et al. (1984), Hooper (1952a), Howell (1914), Long (1962), Merriam (1901b), Meserve (1976), Pearson (1951b), Sanchez (1993), Sanchez & Oliva (2014c), Webster & Jones (1982), Whitford (1976)., 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 372, DOI: 10.5281/zenodo.6707142

224. Rodriguez's Harvest Mouse Reithrodontomys rodriguezi French: Souris-moissonneuse de Rodriguez / German: Rodriguez-Erntemaus / Spanish: Raton espiguero de Rodriguez Taxonomy. Reithrodontomys rodriguezi Goodwin, 1943, Volcan de Iraza, 9400 ft (= 2865 m), Cartago Province, Costa Rica. Reithrodontomys rodriguezi is in subgenus Aporodon. Monotypic. Distribution. Known only from the type locality and surrounding areas in C Costa Rica. Descriptive notes. Head-body 77-83 mm, tail 116-121 mm, ear 14-15 mm, hindfoot 20-21 mm. No specific data are available for body weight. Rodriguez’s Harvest Mouse is medium-sized. Dorsal pelage 1s long, dense, soft, and cinnamon-buff, darkened with black hairs. Venteris white. Tail is longer than head-body length and uniform in color. Feet are white, with dusky outline to bases of toes. Habitat. Grassland adjacent to a wet forest (two specimens) and on slopes of Barva Volcano. Rodriguez’s Harvest Mice have ben trapped on the ground,in low vegetation in elfin forest, and in the fork of a tree c.3 m aboveground. Food and Feeding. Rodriguez's Harvest Mouse was seen feeding on the nectar of Blakea sp. (Melastomataceae) and may be one of the pollinatorsfor this plant. Breeding. A pregnant female was captured in July. Activity patterns. No information. Movements, Home range and Social organization. No information. Status and Conservation. Classified as Least Concern on The IUCN Red List because its extent of occurrence is probably less than 5000 km?; it should be monitored closely. Bibliography. Goodwin (1943), Hall (1981), Hooper (1952a), Timm et al. (1989)., 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 369, DOI: 10.5281/zenodo.6707142

225. Narrow-nosed Harvest Mouse Reithrodontomys tenuirostris French: Souris-moissonneuse a nez aigu / German: Schmalnasen-Erntemaus / Spanish: Raton espiguero de hocico estrecho Taxonomy. Reithrodontomys tenuirostris Merriam, 1901, “Todos Santos, Guatemala (altitude 10,000 ft. [= 3048 m]).” Reithrodontomys tenuirostris is in subgenus Aporodon. Monotypic. Distribution. Extreme SE Mexico (Chiapas State) and SC Guatemala. Descriptive notes. Head-body 80-124 mm, tail 120-129 mm, ear 15-17 mm, hindfoot 20-25 mm; weight 18-23 g. The Narrow-nosed Harvest Mouse is one of the largest species of Reithrodontomys. Dorsal pelage is long and dense, ranging from rich orange to a more reddish color. Numerous black guard hairs give the Narrow-nosed Harvest Mouse a dark appearance. Venter is pinkish cinnamon. Eyes have black rings, and ears have a blackish shade. Skull is characterized by long narrow nasal bones, in contrast to other species of Reithrodontomys. Habitat. Wet, temperate habitats, such as evergreen cloud forests, generally at elevations of 2800-2910 m. Food and Feeding. No information. Breeding. No information. Activity patterns. The Narrow-nosed Harvest Mouse is presumably nocturnal and might be semi-arboreal or even arboreal. Movements, Home range and Social organization. No information. Status and Conservation. Classified as Vulnerable on The IUCN Red List. Bibliography. Arellano & Rogers (1994), Hall (1981), Hooper (1952a), Merriam (1901b), Sanchez (2014d)., 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 369, DOI: 10.5281/zenodo.6707142

234. Volcano Harvest Mouse Reithrodontomys chrysopsis French: Souris-moissonneuse des volcans / German: Vulkan-Erntemaus / Spanish: Raton espiguero de los volcanes Taxonomy. Reithrodontomys chrysopsis Merriam, 1901, “Mt. Popocatapetl, Mexico.” Reithrodontomys chrysopsis is in subgenus Aporodon. Two subspecies recognized. Subspecies and Distribution. R.c.chrysopsisMerriam,1901—fromSEJaliscoEtoPueblastates(CMexico). R. c. perotensis Merriam, 1901 — WC Veracruz State (EC Mexico). Descriptive notes. Head-body 75-85 mm, tail 90-116 mm, ear 17-21 mm, hindfoot 17-21 mm; weight 14 g. The Volcano Harvest Mouse is medium-sized. Dorsum is black, interspersed with bright yellowish orange to reddish orange hairs;sides are mostly ocherousto buff; and venteris pinkish cinnamon. Ears are large and nearly black, with distinct and blackish rings. Tail is distinctly bicolored, black above and light below. Skull is typified by large, oval braincase. Habitat. Cloud forests at elevations of 1830-4100 m. The Volcano Harvest Mouse is typically found in cold, wet forests of pine-fir, pine-oak, and montane grassland and shrubland (zacatonal), and in areas covered with ferns, mosses, and shrubs. It can also be found along hillsides and canyons within cloud forest habitat. Food and Feeding. The Volcano Harvest Mouse eats seeds, grains, and green parts of grasses and other plants. Breeding. No information. Activity patterns. The Volcano Harvest Mouse is nocturnal and arboreal. Movements, Home range and Social organization. Volcano Harvest Mice construct spherical nests of grasses. Status and Conservation. Classified as Least Concern on The IUCN Red List. Populations of Volcano Harvest Mice are naturally limited to high-elevation habitats, and logging and other human activities might be conservation threats. Bibliography. Ceballos & Galindo (1984), Hooper (1952a), Lira & Gaona (2014), Merriam (1901b)., 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 371, DOI: 10.5281/zenodo.6707142

We measured habitat associations in the rodent fauna at the Lyndon B. Johnson National Grassland in north-central Texas from May to August 2011. We recorded five species: hispid cotton rat (Sigmodon hispidus) was most abundant, followed by deer mouse (Peromyscus maniculatus), hispid pocket mouse (Chaetodipus hispidus), fulvous harvest mouse (Reithrodontomys fulvescens), and white-footed mouse (P. leucopus). Cotton rat density increased with grass cover; this effect was stronger for lower and middle quantiles of the abundance distribution. We found weak habitat correlates for P. maniculatus and R. fulvescens. This report is one of few describing the mammalian fauna of the vanishing Grand Prairie ecoregion.

Les captures multiples de petits mammiferes (de >1 animal dans un meme piege) amenent souvent a conclure a une activite de formation de couple chez les rongeurs arvicolines et cricetines. Nous analysons les donnees d'une etude de piegeage de 2 ans afin de determiner si les especes, les souris des moissons fauves (Reithrodontomys fulvescens J.A. Allen, 1894) et(ou) les souris pygmees du Nord (Baiomys taylori (Thomas, 1887)), se deplacent en paires accouplees des deux sexes. Une majorite significative des evenements de captures multiples (MCE) chez R. fulvescens comprenait les deux sexes, alors que la composition des sexes des paires chez B. taylori ne differait pas d'une composition aleatoire. La probabilite des captures multiples est en relation positive significative avec l'abondance, mais non avec le rapport des sexes chez les deux especes. Les captures multiples de B. taylori sont plus nombreuses en hiver, ce qui peut indiquer que les animaux peuvent s'associer afin de se blottir l'un contre l'autre pour se rechauffer. Les masses des individus captures seuls et en groupe ne different pas significativement chez les deux especes, ce qui indique l'absence de biais dans les pieges. Une seule paire de sexes differents prise en couple (R. fulvescens) a ete capturee de nouveau en couple et plusieurs animaux des deux sexes et des deux especes ont ete captures en compagnie de plusieurs autres individus. Nous concluons que les R. fulvescens se deplacent en compagnie de partenaires pour des periodes variables; en revanche, nous ne trouvons aucune indication que les captures multiples de B. taylori soient reliees au comportement reproducteur.

Species co-occurrence is an important ecological research area. Mark-and-recapture studies of mammals allow identification of coexisting species, a necessary step in determining mechanisms enabling habitat sharing. Using data from five 1-ha grids in January 2004 in tropical dry deciduous forest of coastal Colima, Mexico, we detected significantly more interspecific overlap than expected between seven species pairs. Oryzomys couesi shared more stations than expected with Sigmodon mascotensis, Baiomys musculus and Peromyscus perfulvus. Baiomys musculus was associated positively with S. mascotensis and Reithrodontomys fulvescens. Heteromys pictus shared fewer stations than expected with O. couesi and S. mascotensis. For species collectively, there was non-random community structuring, with two grids displaying more species aggregation than expected. While two grids had non-random co-occurrence patterns, three grids did not differ from random, which differs from that reported for mammalian taxa on average. Other small-mammal studies have documented species segregation, while this study detected more positive than negative associations. Similarities in preference and habitat use (or diet) are likely explanations for interspecific overlap patterns at stations and co-occurrence patterns among grids. Simultaneously evaluating associations of species pairs and all species on a grid collectively is novel methodology as applied to mammals, adding to understanding of species co-occurrence.

Livestock grazing and fire influence the composition of desert grassland communities, including their rodent populations. However, there have been few studies of the interactions between grazing and wildfire in arid grasslands of the southwestern United States. We trapped rodents and measured vegetation on grazed versus ungrazed plots before (2001) and following (2002–2007) an intense 15,000 ha wildfire in southeastern Arizona. The fire reduced grass canopy on grazed plots for 2 y and on ungrazed plots for 3 y. Some rodents in the family Cricetidae (genera Baiomys, Reithrodontomys and Sigmodon) were more abundant on ungrazed plots before the fire. Cricetidae as a whole declined following the fire and did not return to preburn levels until the sixth postfire year (2007). Nine of ten cricetid species contributed to this general pattern. By contrast, the abundant species of Heteromyidae (Chaetodipus hispidus, C. baileyi, Perognathus flavus) increased following the fire, especially on ungrazed plots....

Cysticercus fasciolaris is the larval stage of the cestode Taenia taeniaeformis, whose definitive hosts are mainly cats. This larval stage uses a wide variety of small rodents, and occasionally birds and humans, as intermediate hosts. In the Yucatan, there are no reports of the presence of this cestode in animal populations. The aim of this study was to evaluate the occurrence of C. fasciolaris in rodent populations from the Cuxtal ecological reserve, Yucatan, Mexico. Trapping of rodents was conducted from October 2009 to April 2010 in 40 households in Molas, in which Sherman traps were placed both inside and outside backyards. Rodents were dissected to inspect the liver for the presence of the worm. To determine risk factors associated with infection, univariate analysis was performed using sex, age, species, trapping site, and season as independent variables. Variables with a P value Mus musculus was the most abundant (78%), followed by Rattus rattus (13%) and the wild species Peromyscus yucatanicus, Ototylomys phyllotis,Heteromys gaumeri and Reithrodontomys gracilis (9%). Only 7.5% (n = 31) of M. musculus and R. rattus were infected with C. fasciolaris (demonstrated by the presence of liver cysts) with a prevalence of 9.0% and 3.5%, respectively. Both adults and male mice were 4.33 and 3.46 (OR values) times more likely to have C. fasciolaris than juveniles and females respectively. We can conclude that in the Cuxtal Reserve, Yucatan, Mexico, the prevalence of C. fasciolaris is higher in M. musculus, and that adult males had a higher probability of infection. Wild species, mainly P. yucatanicus, were not found to be infected with the cestode, but its presence in the backyards of households could result in a potential risk of acquiring this infection.

The Cudahy “Fauna” was named by C.W. Hibbard for a fossil assemblage recovered from silty clays beneath the “Pearlette” volcanic ash at the type Cudahy ash pit and other sites in Meade County, Kansas. The “Pearlette” ash comprises several variously dated Yellowstone ashes. The Cudahy (=Lava Creek B) ash is most recently dated at 0.639 ± 0.002 Ma and is an important geochronologic marker in the Great Plains. The term Cudahy Ash Pit local fauna is now used for that of the type locality, although other Cudahy-type (Cudahyan) local faunas have been described. From 1968 to 1971, 30 tons of silty clay and diatomite were collected from below outcrops of Lava Creek B ash at elevations of 988–1058 m (3240–3470 ft) in the High Plains of the Texas Panhandle. Screenwashing yielded about 30 mammal taxa and numerous small amphibians, reptiles, birds, and mollusks. Four local faunas (Woody Draw, Bull Draw, Deadman's Creek, and Mayfield Ranch) are recognized. These faunas, dominated by shrews and microtine (arvicoline) rodents, are compositionally similar to each other and to the Cudahy and Sunbrite ash pit local faunas of Meade County even though the Panhandle sites are 300–340 km (186–211 miles) southwest of the Kansas sites and are 213–280 m (700–920 ft) higher in elevation. The Panhandle faunas contain two new species of Sorex as well as Sorex cf. cinereus, Sorex cudahyensis, Sorex lacustris, Sorex ( Microsorex ) pratensis, Sorex megapalustris, Blarina, Cynomys, Spermophilus, Geomys tobinensis, Thomomys cf. talpoides, Peromyscus cragini, Reithrodontomys moorei, Ondatra annectens, Mictomys meltoni, Microtus llanensis (rare), Microtus paroperarius, and Microtus meadensis. The large sample size of the latter two taxa permits statistical comparisons of teeth with those from Kansas. The Texas faunas further substantiate the Cudahyan as a subage of the Irvingtonian between the older Sappan and younger Sheridanian subages and equivalent to Irvingtonian II based on microtine (arvicoline) rodents. Local habitats consisted of ponds or playas with marshy areas suitable for shrews, muskrats, and bog lemmings. Moist grassy meadows nearby would have been inhabited by voles, mice, and some of the shrews; the less abundant gophers, ground squirrels, and prairie dog would have preferred drier, grassy uplands with well-drained soils. Several mammals (e.g. bog lemming) show affinities with extant boreal species that range through Canada and the northern United States The collective evidence suggests that the Texas Panhandle enjoyed cooler summers with more effective rainfall during Cudahy time.

We compared diversity and abundance of small mammals at colonies of black-tailed prairie dogs (Cynomys ludovicianus) and paired non-colony sites. Of colonies of black-tailed prairie dogs in our study area, .80% were on slopes of playa lakes; thus, we used sites of colonies and non- colonies that were on slopes of playa lakes. We trapped small mammals on 29 pairs of sites. Overall abundance did not differ between types of sites, but some taxa exhibited associations with colonies (Onychomys leucogaster) or non-colonies (Chaetodipus hispidus, Reithrodontomys, Sigmodon hispidus). Diversity and evenness of small mammals did not differ between colonies and non-colonies in 2002, but were higher on non-colonies in 2003. Although we may not have detected some rare or infrequently occurring species, our data reveal differences in diversity and evenness of more common species among the types of sites. Prairie dogs are touted as a keystone species with their colonies associated with a greater faunal diversity than adjacent lands. Our findings contradict several studies reporting greater diversity and abundance of small mammals at colonies of prairie dogs. We suggest that additional research across a wider landscape and incorporating landscape variables beyond the immediate trapping plot may further elucidate interspecific associations between black-tailed prairie dogs and species of small rodents.

A new species of the rodent genus Reithrodontomys (Cricetidae: Neotominae) is described from Cerro Asuncion in the western Cordillera de Talamanca, Costa Rica. The long tail, elongate rostrum, bulbous braincase, and complex molars of the new species associate it with members of the subgenus Aporodon, tenuirostris species group. In its diminutive size and aspects of cranial shape, the new species (Reithrodontomys musseri, sp. nov.) most closely resembles R. microdon, a form known from highlands in Guatemala and Chiapas, Mexico. In the course of differentially diagnosing the new species, we necessarily reviewed the Costa Rican and Panamanian subspecies of R. mexicanus based on morphological comparisons, study of paratypes and vouchers used in recent molecular studies, and morphometric analyses. We recognize Reithrodontomys cherrii (Allen, 1891) and R. garichensis Enders and Pearson, 1940, as valid species, and allocate R. mexicanus potrerograndei Goodwin, 1945, as a subjective synonym of R. breviro...

Aim We analysed the distributional patterns of six terrestrial vertebrate taxa from the Oaxacan Highlands (Sierra Mazateca, Nudo de Zempoaltepetl and Sierra de Juarez) through a cladistic biogeographical approach, in order to test their naturalness as a biotic unit. Location The Oaxacan Highlands, Mexico. Methods The cladistic biogeographical analysis was based on the area cladograms of the Pseudoeurycea bellii species group (Amphibia: Plethodontidae), the genus Chlorospingus (Aves: Thraupidae), the genera Microtus, Reithrodontomys and Habromys, and the Peromyscus aztecus species group (Mammalia: Rodentia). We obtained paralogy-free subtrees, from which the components were coded in a data matrix for parsimony analysis. The data matrix was analysed with Nona through

We compared small mammals in Gulf cordgrass (Spartina spartinae) to coastal-prairie and low-marsh, Spartina alterniflora communities, and we considered the effect of standing-crop biomass and nutrient concentration in plants in the Gulf cordgrass community on dynamics of populations of small mammals. We predicted lower species richness and density of small mammals and shorter residence time in Gulf cordgrass because of little vertical habitat structure, sparse ground cover, and low abundance of dicots, plants that contain nutrients necessary for reproduction by hispid cotton rats (Sigmodon hispidus). Richness in Gulf cordgrass (seven species of rodents) was similar to coastal prairie (six species plus three non-native rodents) with S. hispidus and fulvous harvest mice (Reithrodontomys fulvescens) numerically dominant in both communities. Density of S. hispidus was higher in Gulf cordgrass likely reflecting high standing-crop biomass; however, lack of ground cover contributed to low residence time...

1. Roads may affect wildlife populations through habitat loss and disturbances, as they create an abrupt linear edge, increasing the proportion of edge exposed to a different habitat. Three types of edge effects have been recognized: abiotic, direct biotic, and indirect biotic. 2. We explored the direct biotic edge effects of 3- to 4-m wide roads, and also a previously unrecognized type of edge effect: social. We live-trapped two threatened endemic rodents from Cozumel Island (Oryzomys couesi cozumelae and Reithrodontomys spectabilis) in 16 plots delimited by roads on two sides, to compare edge effects between two adjacent edges (corners), single-edge and interior forest, on life history and social variables. 3. No significant edge effects were observed on the life-history variables, with the exception of differences in body condition between males and females of O. c. cozumelae near edges. Both species showed significant and contrasting effects on their social variables. 4. O. c. cozumelae was distributed according to its age and sex: the proportion of adults and males was higher in interior than near edges, while juveniles and females were more abundant near edges. More nonreproductive females were present in corners than in single-edge and interior, while the opposite distribution was observed for nonreproductive males. 5. The distribution of R. spectabilis was related to its age and reproductive condition, but not to its sex. The proportion of adults was significantly higher in corners, while juveniles were only caught in single-edge and interior quadrants. The proportion of reproductive individuals was higher in edge than interior quadrants, while reproductive females were only present in edge quadrants. 6. We found significant differences between the quadrants with the greatest edge exposure in comparison with other quadrants. The social edge effects we identified complement the typology of edge effects recognized in ecological literature. Our study provides insight into the effects that sharp road edges have on biological and social characteristics of small mammal populations, highlighting how such effects vary among species. Our findings have important conservation implications for these threatened species, but are also applicable in a broader context wherever there are abrupt edges caused by linear landscape features.

The northern pygmy mouse (Baiomys taylori), fulvous harvest mouse (Reithrodontomys fulvescens), and Merriam's pocket mouse (Perognathus merriami) are new to the diet of the western burrowing owl (Athene cunicularia hypugaea). All three species were identified from remains in regurgitated pellets collected from roost sites of burrowing owls in southern Texas over a period of 4 winters. Together, northern pygmy mice and fulvous harvest mice represented 58% of mammals identified in 182 pellets regurgitated by western burrowing owls. Merriam's pocket mouse accounted for only 4% of identified mammalian prey. Frequency of occurrence in pellets was 16% for northern pygmy mice, 11% for fulvous harvest mice, and 3% for Merriam's pocket mice. The primary reason for absence of these species in previous studies of foods of western burrowing owls is that most were conducted in latitudes north of these southern-distributed species of mammals.

Maternal nutrition during pregnancy and postnatal offspring nutrition may influence offspring traits. We investigated the effects of maternal and postweaning offspring dietary nitrogen on immune function and hematology in two species of rodent: the hispid cotton rat (Sigmodon hispidus), a primarily herbivorous rodent, and the fulvous harvest mouse (Reithrodontomys fulvescens), an omnivore. These two species responded differently to the same levels of treatment, with cotton rats primarily influenced by maternal diet and harvest mice by postweaning offspring diet. Cotton rats born to mothers on high-nitrogen diets had lower values of mean corpuscle volume and hemoglobin and greater concentrations of serum immunoglobulins. Spleen size, cell-mediated immune response, and the number of splenocytes and thymic platelets were lower in cotton rats born to mothers on low- and high-nitrogen diets. High-nitrogen offspring diet increased kidney and liver mass in cotton rats. Harvest mice had increased kidney mass on high-nitrogen maternal diets; however, changes in offspring diet after weaning reduced hematological parameters in individuals fed low-nitrogen diets. Body length was also affected, with harvest mice born to mothers fed low- and high-nitrogen diets having shorter lengths. Splenocyte cellular activity was greater in offspring born to mothers on high-nitrogen diets in both species.

Peromyscine mice of the cricetid subfamily Neotominae comprise the most common and speciose assemblage of North American rodents. The composition and phylogenetic relationships within this group have been addressed using multiple character systems but remain unresolved, particularly the branching pattern of deeply rooted lineages. The relationships and status of several taxa formerly included within Peromyscus also are controversial. We present a new phylogenetic hypothesis based on combined mitochondrial and nuclear sequences using cytochrome b, interphotoreceptor retinoid-binding protein, and growth hormone receptor gene sequences, and include all major peromyscine lineages. Bayesian and parsimony approaches recover a congruent, well-resolved phylogeny, wherein Peromyscus forms a monophyletic assemblage only if a number of putative genera are included within it. Onychomys rather than Reithrodontomys is the sister taxon to Peromyscus (within which are included Habromys, Osgoodomys, Megadontomys, Podomys, and Neotomodon). Reithrodontomys in turn is the sister taxon to Isthmomys, and these 2 genera are the nearest outlier to Onychomys plus an expanded concept of Peromyscus, consistent with the recent recognition of this entire group as the tribe Reithrodontomyini. The Baiomyini, Ochrotomyini, and Neotoma (Neotomini) appear as successive outgroups to this clade. Based on these results, we present a systematic review of higher-level relationships among peromyscine rodents.

We recorded 12 species of parasitic or phoretic arthropods from 112 live-trapped oldfield mice (Peromyscus polionotus) in southeastern Georgia, U.S.A.: 1 species of sucking louse (Hoplopleura hesperomydis), 1 flea (Peromyscopsylla scotti*), 1 bot (Cuterebra fontinella*), 2 ticks (Dermacentor variabilis and Ixodes scapularis), 3 mesostigmatid mites (Androlaelaps fahrenholzi, Haemogamasus liponyssoides,* and Haemogamasus longitarsus*), 2 fur mites (Glycyphagus hypudaei, Radfordia subuliger*), and 2 chiggers (Euschoengastia peromysci* and Leptotrombidium peromysci*) including the first records (asterisked names) for 7 species from this host. We recorded 4 species of arthropods, all of them mites, from 1 eastern harvest mouse (Reithrodontomys humulis): A. fahrenholzi, R. subuliger, E. peromysci,* and L. peromysci,* including 2 new records (asterisked) from this host. We also recorded 6 species of mites from 5 southern short-tailed shrews (Blarina carolinensis): the mesostigmatids Echinonyssus blarina...

We collected owl pellets from 4 counties to examine the distribution of prairie voles (Microtus ochrogaster) and other small mammals in the Texas Panhandle. We identified 797 individuals of 15 genera and species of small mammals from 207 owl pellets. Overall, the 5 most abundant small mammals, Peromyscus (331 individuals), Reithrodontomys (182 individuals), Cryptotis parva (74 individuals), Sigmodon hispidus, and M. ochrogaster (60 individuals), comprised 89% of all individuals identified. This study extends the known range of M. ochrogaster 24 km south and 13 km east of the previous record in Carson County, Texas, and provides new county records of M. ochrogaster in Armstrong and Ochiltree counties. Additionally, we identified C. parva in samples from Ochiltree and Carson counties and Notiosorex crawfordi in samples from Armstrong County, both of which represent new county records. Our results, along with other recent work on M. ochrogaster, suggest that this species is more widespread in the no...

We examined 590 specimens of Reithrodontomys from 95 localities in the state of Mexico. Four species of the subgenus Reithrodontomys and 1 of the subgenus Aporodon were identified. The former subgenus included R. chrysopsis, R. sumichrasti, R. megalotis, and R. fulvescens, which has 2 subspecies—R. f. toltecus and R. f. mustelinus—in the state. The representative of the subgenus Aporodon is R. microdon wagneri, which is recorded for the first time in the state. We give information on taxonomy, morphometrics, reproduction, habitat characteristics, and related fauna. A discriminant analysis correctly classified 100% of specimens from the 6 taxa with 5 canonical variates, and accounted for 96.1% of the variance with the first 3 canonical variates.