Oecologia Australis 27(2):106–120, 2023 https://doi.org/10.4257/oeco.2023.2702.01 GARRAFÃO PROJECT: ORIGIN, HISTORY AND MAIN ASPECTS OF THE DEVELOPMENT OF THE LONGEST LONG-TERM STUDY OF ECOLOGY OF SMALL MAMMALS IN BRAZIL Rosana Gentile 1* , Diogo Loretto 2 , Maja Kajin 3 , Simone R. Freitas 4 , Ricardo Finotti 5 , Marcus Vinícius Vieira 2 , Rui Cerqueira 2 1 Fundação Oswaldo Cruz, Instituto Oswaldo Cruz, Laboratório de Biologia e Parasitologia de Mamíferos Silvestres Reservatórios, Av. Brasil 4365, CEP 21040-360, Rio de Janeiro, RJ, Brasil. 2 Universidade Federal do Rio de Janeiro, Instituto de Biologia, Departamento de Ecologia, Laboratório de Vertebrados, Centro de Ciências da Saúde, Av. Carlos Chagas Filho, 373, CEP 21941-902, Rio de Janeiro, RJ, Brasil. 3 University of Oxford, Department of Biology, 11a Mansfeld Road, OX1 3SZ Ox ford, United Kingdom. 4 Universidade Federal do ABC, Centro de Ciências Naturais e Humanas, Avenida dos Estados, 5001, CEP 09210-580, Bloco A, Torre 3, 6° andar, sala 631-3, Santo André, SP, Brasil. 5 Universidade Estácio de Sá, Unidade R9, Rua André Rocha, 838, CEP 22710-560, Taquara, Rio de Janeiro, RJ, Brasil. E-mails: rgentile@ioc.focruz.br (*corresponding author); diogoloretto@gmail.com; majakajin@biology.ox.ac.uk; simonerfreitas.ufabc@gmail.com; fnottiricardo@gmail.com; mvvieira@gmail.com; rui48@gmail.com Abstract: This article introduces the special volume dedicated to one of the longest wildlife monitoring programs ever carried out in Brazil: the long-term study on small mammals developed by the Laboratório de Vertebrados at UFRJ from 1996 to 2019 in Garrafão, municipality of Guapimirim, Rio de Janeiro. The guiding ideas of this study emerged from a previous project developed at the Restinga de Barra de Maricá, RJ, in the 1980s on the ecology of small mammal populations and communities. The main research objectives were related to community structure, population growth and population dynamics, aiming to understand the ecological processes and the mechanisms explaining the fuctuation of population size in several species over time. Initially, models of genetic population structure and population dynamics were tested. Further developments in the project allowed other aspects to be studied, such as diet and nutritional requirements of the animals, population genetics, use of space, habitat, biogeography, taxonomy, and systematics. These approaches, based on relevant ecological questions, have provided advances in knowledge in several areas of biology, especially in population ecology. The study resulted in dozens of articles, book chapters, dissertations and theses and was interrupted by conjuncture factors and abrupt changes in the funding policy for the development of scienti fc research in Brazil. Keywords: habitat selection; litterfall production; marsupials, population biology; rodents. INTRODUCTION This special volume of Oecologia Australis is dedicated to the Garrafão Project, one of the longest and uninterrupted monitoring studies of small mammals ever carried out in Brazil, developed by the Laboratório de Vertebrados (LabVert) at the Universidade Federal do Rio de Janeiro (UFRJ), coordinated by Professor Rui Cerqueira. Considering long-term studies of the