Small mammals of the Estação Ecológica de Bananal, southeastern Atlantic Forest, Brazil, with description of a new species of Brucepattersonius (Rodentia, Sigmodontinae)

Abstract

The Atlantic Forest harbors an impressive diversity of nonvolant small mammals. Despite having been the target of many ecological and taxonomical studies in the last decades, this group is still poorly known in several aspects – basic information on intrapopulational morphologic variation and proper diagnoses are lacking for many species, even for common taxa. This is related to the fact that large series of specimens from a single locality are extremely rare in scientific collections. A consistent sampling effort was conducted at Estação Ecológica de Bananal, northeastern São Paulo State, throughout seven field expeditions between 2003 and 2011, under the coordination of the Museu de Zoologia da Universidade de São Paulo, resulting in extensive series of nonvolant small mammals. We studied in detail the external and cranio-dental morphology of this sample (575 specimens), that we assigned to 31 known species besides one new species to science. Most species belong to order Rodentia (26 species) from the families Cricetidae (22 species) and Echimyidae (four species); the remaining (six species) are marsupials from the order Didelphimorphia, family Didelphidae. This is one of the most diverse assemblages ever recorded in this biome, and includes some of the rarest endemic rodents of the Atlantic Forest, such as Abrawayaomys ruschii, Blarinomys breviceps, Drymoreomys albimaculatus, Phaenomys ferrugineus, Phyllomys kerri and Rhagomys rufescens. This outstanding richness can be explained by the extensive sampling effort performed for a long period of time. Also, the capture success of the third expedition (8.25%) is among the highest rates obtained in the Atlantic Forest and the extensive use of pitfall traps was fundamental for trapping this high number of species. Herein, we provide an annotated list of nonvolant small mammals occurring at Estação Ecológica de Bananal, with comprehensive analyses of morphological variation and detailed diagnoses that will allow their proper identification, and will provide a sound basis for a better comprehension of the geographic variation of these taxa across the biome. We also present a formal description for a new species of Brucepattersonius from the mountain ranges along the Paraíba do Sul valley. For five species of sigmodontine rodents, we investigate the levels of ontogenetic and sexual variation, and while the first is accentuate in all analyzed species the second does not contribute significantly to intrapopulation variation.

Insectivory leads to functional convergence in a group of Neotropical rodents

“…The Akodontini tribe, the second most diverse tribe of Sigmodontinae, is characterized by a successful radiation in South America (D’Elía & Pardiñas, 2015; Maestri et al., 2017; Reig, 1972, 1987). In addition to being one of the tribes with the greatest taxonomic diversity (88 species; de Abreu‐Júnior & Percequillo, 2019; Pardiñas et al., 2017; Peçanha et al., 2019), akodontines are also particularly diverse in adaptive types (D’Elía & Pardiñas, 2015; Hershkovitz, 1966; Reig, 1972, 1987), including specialized fossorial genera ( Blarinomys ), the largest living sigmodontines ( Kunsia , Gyldenstolpia and Scapteromys , reaching up to approximately 650 g; D’Elía & Pardiñas, 2015), and more generalist cursorial rodents ( Akodon and Necromys genera; D’Elía & Pardiñas, 2015). Akodontini also includes nearly 70% of the insectivorous rodents in South America (D’Elía & Pardiñas, 2015; Reig, 1972, 1987; Maestri et al., 2017).…”

Ficha de Brucepattersonius nebulosus

“…Análises moleculares sugeriram que B. griserufescens compreendia, na verdade, dois táxons distintos (Dias, 2016). Com um espécime coletado na Estação Ecológica do Bananal-SP, foi possível compará-lo, com análises genéticas e morfológicas, com outros espécimes depositados em museus e concluiu-se que parte destes animais trata-se, na verdade, de uma espécie distinta, batizada de Brucepattersonius nebulosus, em referência a seu habitat, florestas nebulares (Abreu-Júnior & Percequillo, 2019).…”

“…Espécie de tamanho médio, apresentando em média, comprimento de cabeça e corpo de 99,4 mm, comprimento de cauda de 97,91 mm e peso médio de 25,55 g; distingue-se das outras espécies do gênero por uma combinação de aspectos morfológicos, como: pelagem dorsal marrom-escuro, pelagem ventral amarelo-acinzentado ligeiramente esbranquiçado, cauda geralmente menor que o comprimento de cabeça e corpo e uniformemente marrom-escuro, crânio com rostro estreito, forame incisivo longo e ponte palatina curta (Abreu-Júnior & Percequillo, 2019).…”

Atlas Craniano Mamíferos da Mata Atlântica e lista de espécies

“…To complement the atlas, we present here an updated checklist of the mammals occurring in the Atlantic Forest (according to the definition employed throughout this publication) and added species that might be found marginal to this domain, plus the exotic and introduced mammals. We used the Annotated Checklist of Brazilian Mammals (Paglia et al, 2012), the Checklist of Brazilian bats, with comments on original records (Nogueira et al, 2014), Mamíferos da Mata Atlântica (Graipel et al, 2017) and Lista de mamíferos do Brasil (Abreu Júnior et al, 2020a) as a foundation, and added the recent records (Guerra & Costa, 2019;Abreu Júnior et al, 2020b;Cláudio et al, 2020;Vela-Ulian et al 2021), and species recently validated (Ruedas et al, 2017;Nascimento & Feijó, 2017;Voss et al, 2019;Basantes et al, 2020) or described (Gurgel-Filho et al, 2015;Christoff et al, 2016;Gregorin et al, 2016;Pardiñas et al, 2016;Quintela et al, 2017;Machado et al, 2018;Abreu Júnior & Percequillo, 2019;Peçanha et al, 2019). A few species listed by Paglia et al (2012), Nogueira et al (2014 and/or Graipel et al (2017) were not included herein because we considered them as subspecies (see Feijó et al, 2018) or junior synonyms (see Patton et al, 2015;Pavan & Voss, 2016;Voss et al, 2019;.…”