Records of small mammals in the Calakmul Biosphere reserve, Yucatan Peninsula

摘要

During an inventory of mammals of the Calakmul Biosphere Reserve in Campeche, in 1993-1994, several species of small mammals were collected that represent important re- cords for the Yucatfin Peninsula. The Calakmul Biosphere Reserve is located in the south-central yucatan Peninsula, comprising an area of 723,185 ha. It forms part of the Biotic Province of Yucatfin (Barrera, 1962) and it is, together with the Maya Biosphere Reserve and the Montes Azules Biosphere Reserve, one of the most important reservoirs of biodiversity in northern Middle America. Its topography consists of an extensive plain, with elevations no greater than 250 m above sea level. Surface drainage is scarce; because of that, the aguadas (more or less permanent ponds) are the principal sources of water in the area and become extremely important for fauna. Climate of the region is humid-warm with a mean annual temperature range from 24 to 26 deg C. Maximum temperatures at the north of the reserve are higher than those in the south. Precipitation also grades from 1,000 mm annually in the north to 1,300 mm in the south. Principal types of vegetation present in the reserve are variants of tropical semideciduous forest (Rzedowski, 1978). The high (20 to 25 m) forest is characterized by dominant trees such as Manilkara zapota (zapote), Swietenia macrophylla (caoba), Bursera simaruba (chaca), and Astronium graveolens (jobillo). The medium-height (10 to 20 m) forest has Bucida buceras (pukte), Lysiloma latisiliquum, Cecropia obtusifolia (guarumbo), and Ceibapentandra. The low ((10 m) and flooded forest has Haematoxylon campechianum (tinto), Metopium brownei (chechem) and Mimosa bahamensis.