John O. Matson

Patterns of phenotypic and genetic variation in three species of endemic Mesoamerican Peromyscus (Rodentia: Cricetidae)

Abstract Three species of Mexican deer mice of the Peromyscus mexicanus species group (P. grandis, P. guatemalensis, and P. zarhynchus) were characterized morphologically and genetically to test hypothesized concepts of species limits. We investigated if previously proposed phenetic relationships among these 3 taxa were supported by morphometric and genetic data. Analyses of nongeographic and geographic variation for individuals from 36 localities in Guatemala and southeastern Mexico were conducted to assay morphologic and geographic boundaries. In addition, 35 mitochondrial cytochrome-b gene sequences were analyzed using maximum-parsimony and Bayesian inference methods to determine relationships among the 3 taxa. This study based on comparisons to type specimens provided support for the presence of 3 morphologically and genetically distinct units. Our analyses suggest that P. grandis and P. guatemalensis are more closely related to each other than either is to P. zarhynchus, rejecting existing hypotheses that suggest that P. zarhynchus and P. grandis are phenetically more similar. The results of this study depict relationships among other members of the P. mexicanus group and patterns of speciation and biogeography and allow identification of regionally important phylogeographic units in Mesoamerica.

COYOTES (CANIS LATRANS) IN GUATEMALA

Abstract Records of coyotes (Canis latrans) from Guatemala are based mostly on observational records. We review existing literature for coyotes in Guatemala and report the first specimen from this country.

The taxonomic status of Long-tailed shrews (Mammalia: genus Sorex ) from Nuclear Central America

We examined 256 specimens of long-tailed shrews (Sorex) from 53 localities throughout the highlands of Nuclear Central America. We evaluate the efficacy of using three qualitative characteristics to identify populations of Sorex from Nuclear Central America: 1) the presence or the absence of a postmandibular foramen and canal; 2) relative size of U3 compared to U4; and, 3) the presence or absence of a pigmented ridge on the lingual side of each unicuspid tooth. In our data, the first character is invariable for the specimens we examined. Two species groups can be recognized based on the presence (S. salvini species group) or the absence of a postmandibular foramen and canal (S. veraepacis species group). The other two characteristics were useful, but not diagnostic. Based upon Principal Component Analysis we recognize nine species of Sorex in Nuclear Central America. Five species belong to the S. salvini species group: S. cristobalensis, S. salvini, S. sclateri, S. stizodon, and a new species from Honduras. Four species belong to the S. veraepacis species group: S. chiapensis, S. ibarrai, S. veraepacis, and a new species from western Guatemala. We also present evidence that the type locality (Cobán, Alta Verapaz, Guatemala) for S. veraepacis is not correct.

Small Mammals from Three Mountain Ranges in Nuclear Central America

ABSTRACT Small mammal ecology and natural history are poorly known in Nuclear Central America. In an effort to gain information on small mammals (insectivorans, marsupials, and rodents), we sampled three cloud forest habitats in mountain ranges in Honduras (Cerro Celaque and Sierra de Agalta) and Guatemala (Sierra de las Minas). Small mammals were collected using removal trapping. A total of 789 specimens representing 23 species of small mammal was recorded from seven trapping sites. Trapping effort varied among sites, with a total of 18,117 total trap nights recorded. We describe the habitat at each trapping site, and report on species diversity, relative abundance, sex ratios, reproductive activity, and other natural history information on the mammals collected. In general, cloud forests in the three mountain ranges contained different communities of small mammals. We recorded only three species, Heteromys desmarestianus Gray, 1862, Peromyscus oaxacensis Merriam, 1898, and Scotinomys teguina (Alston, 1877), on all three mountain ranges.

Range Expansion of the Western Gray Squirrel (Sciurus griseus) in Northeastern California

ABSTRACT. We report the first records of the western gray squirrel (Sciurus griseus) from Modoc County and eastern Lassen County in northeastern California. Specimens from Modoc County represent the first records of the species from the Great Basin geographic province. We conclude that these records represent a range expansion based upon previous fieldwork that did not report the species in the region.