An Addition to the Mammalian Fauna of Saskatchewan: The Western Harvest Mouse, Reithrodontomys megalotis

The Western Harvest Mouse (Reithrodontomys megalotis) is rare in Canada, and its distribution is believed to be restricted to south-central British Columbia and southeastern Alberta. Between 2008 and 2010, we identified Western Harvest Mouse hairs in 71 of 1424 scats (5%) of Red Fox (Vulpes vulpes), Coyote (Canis latrans), American Badger (Taxidea taxus), and Long-tailed Weasel (Mustela frenata) collected in southwestern Saskatchewan. The presence of Western Harvest Mouse was confirmed at the same latitude as populations reported in Alberta and British Columbia, in scats collected in or nearby grasslands. This is the first time that the presence of the Western Harvest Mouse has been confirmed in Saskatchewan.

Helmintos y sifonápteros parásitos de cinco especies de roedores en localidades de la Cuenca Oriental, en el centro de México

La Cuenca Oriental se ubica en los estados de Puebla, Tlaxcala y Veracruz, localizada en el Eje Volcánico Transmexicano; hasta la fecha, sólo se han registrado en la localidad dos especies de helmintos (Caballerolecythus ibunami y Lamotheoxyuris ackerti) y tres sifonápteros (Anomiopsyllus perotensis, Stenistomera alpina y Echidnophaga gallinacea). Para el presente trabajo se realizaron dosmuestreos, en junio de 2007 y julio de 2008, los cuales incluyeron cinco localidades de la región, colectándose ocho taxa de helmintos y nueve de pulgas, todos provenientes de Liomys irroratus, Dipodomys phillipsii, Peromyscus difficilis, P. maniculatus y Reithrodontomys megalotis. Se registran nuevos hospederos y localidades para México en siete taxa de helmintos y sólo uno para las pulgas.

Lista actualizada y estado de conservación de los mamíferos del Parque Nacional el Chico, Hidalgo, México. 563-583.

Se presenta la lista actualizada de los mamíferos del Parque Nacional El Chico con base en el trabajo de campo realizado entre los años 2004 y 2006. Se identificaron 30 especies, 13 de ellas se registran por primera vez en el parque: Glaucomys volans, Peromyscus melanotis, Reithrodontomys megalotis, R. sumichrasti, Spilogale gracilis, Cryptotis mexicana, Sorex saussurei, Dermanura azteca, Corynorhinus towsendii, Eptesicus fuscus, Lasiurus cinereus, Myotis californicus y M. velifer. El orden mejor representado, con 10 especies (33.33 %) fue Rodentia, seguido por Carnivora con ocho especies (26.67 %). El 16.67 % de las especies están consideradas en estado de conservación delicado (C. mexicana, S. saussurei, Sciurus oculatus, G. volans y Corynorhinus mexicanus). Localmente las amenazas para la mastofauna son consecuencia de los asentamientos humanos y el turismo descontrolado. El Chico es importante para la conservación y manejo de los mamíferos de Hidalgo, porque en el habita el 23.8 % de la mastofauna estatal, no obstante su reducida extensión territorial (2,739 ha).

Dynamics of Peripheral Populations of Great Basin Pocket Mice, Perognathus parvus, and Western Harvest Mice, Reithrodontomys megalotis, in Southern British Columbia

The Great Basin Pocket Mouse (Perognathus parvus) and Western Harvest Mouse (Reithrodontomys megalotis) are two peripheral species occurring in the southern Okanagan Valley of British Columbia, Canada. Both species are listed as vulnerable to extirpation because of habitat loss, primarily due to conversion of natural habitat to agricultural uses and suburban expansion. Population dynamics of these two species were studied in three habitat types: old field, sagebrush, and pine forest. The Great Basin Pocket Mouse occurred at densities ranging from 12 to 28/ha in sagebrush habitats and at 2-8/ha in old fields and Ponderosa Pine forest. The Western Harvest Mouse occurred at variable densities up to 10/ha in old fields and up to 5/ha in sagebrush habitats. Mean number of lactating females for Great Basin Pocket Mice ranged from 4-8 in sagebrush, 1-5 in old fields and pine forests combined. Mean juvenile survival to adulthood ranged from 3.28 young Great Basin Pocket Mice per pregnant female in sagebrush, 4.67 in old field, and 1.82 in pine forest habitats. Mean juvenile survival to adulthood of Western Harvest Mice ranged from 1.46-1.72 young per female in old field and sagebrush habitats. Conservation of habitat features (high biomass and structural diversity of grasses and forbs) in linear habitats has the potential to maintain populations of Western Harvest Mice. The Great Basin Pocket Mouse needs features of sagebrush and old field habitats that need to be conserved as natural non-linear components in mosaics of natural and anthropogenic habitats. Both species could act as “indicators” of habitat integrity for a wide range of other vertebrate, invertebrate, and plant species in the Okanagan Valley.