Community structure and population dynamics of small mammals in an urban-sylvatic interface area in Rio de Janeiro, Brazil

Abstract

ABSTRACT. The Atlantic Forest is one of the most disturbed Brazilian biomes, with 183 out of 298 species of mammals occurring in the state of Rio de Janeiro. In this study, we aimed to characterize the diversity, community structure, and habitat use of small mammals in the FIOCRUZ Atlantic Forest Campus (CFMA), including areas of Pedra Branca State Park (PBSP, subunit Pau da Fome), state of Rio de Janeiro. We also compared species diversity and composition between two moments 15 years apart (2001 and 2012-2015) and analyzed the population dynamics of the marsupial Didelphis aurita (Wied-Neuwied, 1826). Small mammal captures were made in different habitats: sylvatic-urban interface areas near human dwellings, disturbed forest, and preserved forest areas. Five marsupial species and four rodent species were captured in both periods. There was a reduction in species richness and β diversity between the two periods, indicating that disturbances in the environment over the years may have affected the small mammal community structure. The most altered environment showed the greatest species richness and abundance, while the forest areas showed the smallest values, which may be explained by the loss of mammal species, mainly specialist species in forested areas. We identified three groups of species according to habitat preferences: one related to environments with a higher density of vegetation in upper strata -Marmosa paraguayana (Tate, 1931) and Monodelphis americana (Müller, 1776), another related to a higher density in lower forest strata -Akodon cursor (Winge, 1887), and another with no association with the investigated habitat variables -D. aurita and Oligoryzomys nigripes (Olfers, 1818). The small mammal community structure showed a low level of nestedness in both sampling periods. This study is the first report to evaluate the community structure of small mammals in the sylvatic-urban interface area of Pedra Branca State Park, the largest forest reserve within an urban area in Brazil. The surveys indicate that the small mammal diversity was low in both sampling periods and in both areas, and a species loss in the Pau da Fome locality was observed, despite it is a conservation unit. The greater species abundance and richness in the most disturbed areas suggest an increase of factors favoring the occurrence of synanthropic and opportunistic species.

Trypanosomatid Richness in Wild and Synanthropic Small Mammals from a Biological Station in Rio de Janeiro, Brazil

“…D. aurita was the most abundant small mammal in the samplings from EFMA, probably because capture expeditions occurred during their reproductive period, described to begin in July/August and to finish in March [26]. As a consequence, most of the isolated parasites in this study were derived from this species, which certainly influenced the ecological pattern of the local enzooty.…”

“…For this reason, several initiatives were proposed, aiming to mitigate the effects of human occupation in this environment, such as the implementation of a biological station named Estação Biológica FIOCRUZ Mata Atlântica (EFMA: Fiocruz Atlantic Forest Biological Station). The EFMA is a part of the campus FIOCRUZ Mata Atlântica (CFMA-FIOCRUZ Atlantic Forest Campus), and is currently an environmentally protected area surrounded by low-income communities [25][26][27]. In this area, several scientific research projects have been developed, including the monitoring of fauna [26] and its parasites [17,28].…”

“…The EFMA is a part of the campus FIOCRUZ Mata Atlântica (CFMA-FIOCRUZ Atlantic Forest Campus), and is currently an environmentally protected area surrounded by low-income communities [25][26][27]. In this area, several scientific research projects have been developed, including the monitoring of fauna [26] and its parasites [17,28].…”

Testis structure, duration of spermatogenesis and daily sperm production in four wild cricetid rodent species (A. cursor, A. montensis, N. lasiurus, and O. nigripes)

“…As a consequence, changes have occurred in the natural habitats and species diversity [25], which can favor generalist and opportunistic species to increase their densities and dispersion, as well as increasing the number of agricultural pests and changing the natural prevalence of zoonotic pathogens in wild reservoirs [26][27][28]. Moreover, the wild rodents herein investigated are classified as opportunistic species and reservoirs of zoonotic pathogens [2,[29][30][31][32][33][34]; understanding their reproductive behavior is very useful to develop conservation management strategies. For instance, the evaluation of reproductive organs in different species allows a better comprehension of distinct reproductive strategies and physiological specificities related to each species [35][36][37][38][39][40][41][42].…”

Influência da Temperatura e Umidade Relativa sobre Pequenos Mamíferos em Fitofisionomias de Elevada Altitude no Sudeste Brasileiro

“…E está em consonância com outros trabalhos realizados em ambientes de elevada altitude (Bonvicino et al, 2005;Godoi et al, 2010;Cáceres et al, 2011). A riqueza é considerada como elevada quando comparada com outros trabalhos no sudeste brasileiro (ver Lessa et al 1999;Umetsu & Pardini 2007;Gentile et al 2018) e a diversidade de pequenos mamíferos da Chapada das Perdizes merece atenção do ponto de vista conservacionista pelo registro de espécies consideradas de difícil captura em inventários de pequenos mamíferos (ver Machado et al, 2016).…”