Non-volant small mammals of the Atlantic Plateau of São Paulo: identification, natural history and threats

Author(s)

Natália Fernandes Rossi

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB)
• Defense date: 2011-06-13

Examining board members

Renata Pardini; Ana Paula Carmignotto; João Alves de Oliveira

• Advisor: Renata Pardini

Abstract

Rodents from the families Cricetidae and Echimyidae and Didelphidae marsupials represent the non-volant small mammals from Neotropical forests, a group that encompasses much of the diversity of mammals in Brazil, play important ecological roles in forest regeneration and dynamics, and indicates changes in both landscape and local habitat structure. However, species identification is difficult since taxonomy is mainly based on cranial and chromosomal characters, many species are still being described, and recent lists for many biomes and regions are lacking. Moreover, despite their numerical and ecological importance, there is a lack of information, syntheses and compilations on the diagnosis, natural history, distribution and threats to the species of this group. This dissertation presents a compilation of the current knowledge about the diagnostic characters, distribution, habitat use and responses to human disturbances, diet, use of space, reproduction and threats for the non-volant small mammals from one of the richest regions of the Atlantic Forest, the Atlantic Plateau of São Paulo, where two adjacent areas of endemism meet, and which harbors about 22 and 32% of Cricetidae rodents and Didelphidae marsupials occurring in Brazil. Species diagnosis were based on the comparison and description of the same characteristics for all species, focusing mainly on external characters, which can be analyzed in live animals and some dental and cranial features most relevant to the analyzed groups. The description of ecological characteristics was based on an extensive database collected at 155 sites with an effort of 118.322 traps-night by the projects of the Laboratory of Diversity and Conservation of Mammals, Department of Zoology, Institute of Biosciences, University of São Paulo, and a standardized review of the literature. For each of the 53 species, I present information on: 1- \"Identification\" that includes external body measurements (minimum, maximum and mean), a text on diagnosis that describes the external morphological and cranial characteristics illustrated in figures and plates, and karyotype; 2- \"Distribution\" that describes the geographical distribution followed by information on the occurrence in Brazilian biomes and states, and the distribution and abundance in forests of the Atlantic Plateau of São Paulo; 3- \"Natural History\" where the preference for forests or open areas of agriculture, the response to forest fragmentation and regeneration, the ability to occupy different types of altered habitats, diet, habit, reproduction, use of space and other important information are described; and 4- \"Threats\" that highlights the presence in state, national and international lists of endangered species and presents a consideration of the threats, based on the detailed information obtained in the Atlantic Plateau of São Paulo. (AU)