New occurrences and biological aspects to four species of rodents (Mammalia: Cricetidae) from Brazil

The most representative group among mammals are rodents for presenting high ratio to the total of species. However, rodents are considered a “taxonomic chaos” and some species such as Blarinomys breviceps, Bibimys labiosus, Akodon lindberghi and Pseudoryzomys simplex are little known. That can be explained because of low occurrence of small terrestrial mammals in wildlife inventories and/or reduced abundance. The objective is to describe the occurrence of these species and analyze these locations presenting descriptive comments about their biological aspects. Therefore, in addition to specimens collected in the field, some scientific collections were visited and reviews in relevant literature were conducted in order to obtain information about the locations and biological aspects. Akodon lindberghi was found in five sites, Bibimys labiosus was found in 15, Blarinomys breviceps in 39 and Pseudoryzomys simplex in 13. Each species has specific information and they are included in two threatened areas, Atlantic Forest and Cerrado. The occurrences are disconnected and related to taxonomic and methodological problems.


Introduction
The group of mammals from Brazil has been recently compiled by Paglia et al. (2012), presenting 701 mammalian species.The most representative group of mammals is the sigmodontine rodents, representing 34.7 % of all diversity compiled.On average, as mentioned by Patterson (2000), scientists described a new genus and eight new species each year.
Despite the representativeness, the group of rodents is considered a "taxonomic chaos".Taxonomic information and natural history are disjoint affairs.Specialists are compelled to gather a lot of books and articles to collect the necessary information to fully understand the group.Recently, some efforts to systematize these information generated unprecedented papers.Among them, we can men-MACHADO F. S.; LIMA I. J.; LOPES A. P. M.; MOURA A. S. de; ABREU T. C. K. de New occurrences and biological aspects to four species of rodents (Mammalia: Cricetidae) from Brazil.Revista Agrogeoambiental, Pouso Alegre, v. 8, n. 2, p. 35-51, Jun. 2016.DOI: http://dx.doi.org/10.18406/2316-1817v8n22016800tion the taxonomic keys (which are vital for understanding biodiversity) in Bonvicino et al. (2008), Weksler and Percequillo (2011) and Patton et al. (2015).Even so, some groups are poorly known . De Vivo (2007) mentions that these problems are a result of the small number of taxonomists, repulse in sacrificing and collecting specimens for scientific collections, preparation of material in wet and dry way in the wrong form, lack of source from material, problems in identification and the method not being appropriate to capture certain groups.
Besides these problems, some species still present low occurrence in small terrestrial mammal wildlife inventories and/or low abundance.These species are considered rare for this paper.The species Blarinomys breviceps and Bibimys labiosus began to be caught more frequently in the late 1990s by increasing the use of pitfall traps (Silva et al., 2003).Akodon lindberghi was commonly mistaken for young animals of the same genus due to its small size (Gonçalves et al., 2005).Finally, Pseudoryzomys simplex has not been typically captured by conventional methods such as tomahawks, Sherman traps and pitfall traps (commonly recorded by owl regurgitation - TALAMONI et al., 2000;PARDIÑAS et al., 2004;TETA et al., 2009;TETA;PARDIÑAS, 2010).
Then, targeting the relevant problematic understanding of that group, the objectives were to show new localities of occurrence of Blarinomys breviceps, Bibimys labiosus, Akodon lindberghi and Pseudoryzomys simplex; describe their geographic distributions and, additionally, present comments on its biological aspects.

Specimen collection and sites of occurrence
Individuals were collected from June 2009 to April 2010 in five sites that comprised two stretches of semi deciduous forest (one at 1,300 m and the other at 1,400 m high), one of natural grassland (at 1,500 m) and two at cloud forests (at 1,550 m) in the "Chapada das Perdizes" (21° 35'S 44°33'W), located between the cities of Minduri and Carrancas (Minas Gerais state, Brazil).At each of these locations, different types of live-traps were installed: Shermann ® , Tomahawk ® and pitfall.Individuals were collected through license of IBAMA -ICMBio (permanent license 18528-2) and deposited at the Coleção de Mamíferos da Universidade Federal de Lavras (CMUFLA).The material consisted of skins, skulls and carcasses preserved on alcohol 70 %.All the proceedings of capture, manipulation, collection and preservation of material followed the protocol of Sikes et al. (2011).
Specimens deposited in scientific collections and data from the literature were used (Tables 1, 2, 3 and 4).The collections visited were: Coleção de Mamíferos da UFLA (CMUFLA), Museu de Zoologia da Unicamp (ZUEC), Laboratório de Diversidade e Conservação de Mamíferos da Universidade de São Paulo (DICOM/USP) and Laboratório de Ecologia e Conservação de Mamíferos da UFLA (LECOM/UFLA).The vegetation type of each location is presented according to the literature or registration in Tombo book /identification card (Livro de Registo/Livro de Tombo in Portuguese).

Results
The known geographic distribution of A. lindberghi comprises the state of Minas Gerais and Distrito Federal with only five sites of occurrence (Figure 1).The sites are located in Cerrado, Atlantic Forest and the ecotonal zone between both domains.The altitude in which A. lindberghi appeared varied from 550 to 1,500 m.Table 1 contains information about the areas.Source: Created by the authors.Bibimys labiosus is found in the states of Minas Gerais, Rio de Janeiro, São Paulo, Paraná, Santa Catarina and Rio Grande do Sul, reaching a total of 17 sites of occurrence (Figure 2).The localities include the domains of Cerrado, Atlantic Forest and the ecotonal zone between both domains.The occurrence of this species ranged from 650 to 1,550 m high.Table 2 presents information related to the records of B. labiosus.The records of B. breviceps appeared in the states of Bahia, Minas Gerais, Espírito Santo, Rio de Janeiro and São Paulo, with a total of 39 sites of occurrence (Figure 3).The Atlantic domain is predominant in the areas of occurrence, but the species was also found in areas of Cerrado and ecotonal regions between Atlantic and Cerrado.The points of occurrences ranged from four to 1,570 m high.Table 3 contains information related to B. breviceps records.Pseudoryzomys simplex appears in the states of Pernambuco, Bahia, Minas Gerais, São Paulo, Tocantins, Goiás and Distrito Federal meeting a total of 14 sites of occurrence (Figure 5).The predominant domain in which P. simplex appeared was Cerrado.Although, there are records for Atlantic Forest and ecotonal regions between Cerrado and Atlantic Forest.The occurrence ranged from 140 to 1,550 m high.Table 4 contains

Discussion
Information related to Akodon lindberghi on the literature is scarce; hence, the species is classified as vulnerable on Cerrado by IUCN (MARINHO-FILHO et al., 2008).Our record (Minduri/Carrancas towns) adds information about this species occurrence.Figure 1 evidences the considerable gap in the points and this may be caused mainly by problems with the correct identification of animals from the genus Akodon in the field, as well as lack of material collection and appropriate proceedings in identifying specimens, non-karyotyping for example.Indeed, Vivo (2007) pointed out that those proceedings are doubtful because they do not have control material to make the identification, which prevents the comprehension of part of its biology.
Furthermore, Gonçalves et al. (2005) mention the need for a taxonomic revision of A. lindberghi and Akodon mystax.Both species belong to the group of small Akodon and what differentiates one from the other is qualitatively the presence or absence of masseteric tubercle.If a species is a synonym of the other, the number of locality can triple (see occurrence to both species in Gonçalves et al., 2005).
The type locality of A. lindberghi is the Parque Nacional de Brasília inserted in the biome Cerrado, but the species also were found in areas of Atlantic Forest and the ecotone Atlantic Forest/Cerrado, corroborating Queirolo and Granzinolli (2009) and Paglia et al. (2012).
Although B. labiosus is not classified in any threaten degree, its population are fragmented and tend to decrease (PARDIÑAS et al., 2008a), chiefly due to the current situation of biomes preservation in which it occurs, Cerrado (PARDIÑAS et al., 2008a) andAtlantic Forest (PAGLIA et al., 2012).Rovida (2010) asserted that this species is endemic of Cerrado; Paglia et al. (2012) mentioned the occurrence of this species exclusively to Atlantic Forest.However, records from CMUFLA show its occurrence in an ecotonal region between Cerrado and Atlantic Forest.Therefore, more studies related to biology and zoogeographies of those species are necessary.
In addition, the specimen in LECOM/UFLA was captured within the urban area of Lavras, near a forest called "Cerradinho" that is highly modified for various research activities conducted by UFLA.Thus, and as exposed by Lessa et al. (1999), it is believed that B. labiosus requires low demands from the environment.
Blarinomys breviceps is not classified in any threaten degree.However, its populations are fragmented and tend to decrease (PARDIÑAS et al., 2008b).This species presents wide distribution (PAGLIA et al., 2012), including the Atlantic domain (predominant in the occurrence areas), Cerrado (SILVA et al., 2003) and ecotonal regions between these two domains.This species is associated to both montane regions and forests of low elevation (SILVA et al., 2003;PARDINI, 2004).All of the specimens from CMUFLA, for example, were captured in pitfalls, at approximately 1,550 m in cloudy forests.The species is considered rare, but the scarcity of records may be explained by the potential low population density (PEREIRA et al., 2008) and also by sampling aspects.Indeed, Umetsu et al. (2006) pointed out that small pitfalls (35 L capacity) may be efficient on capturing more individuals of Blarinomys, but that is a recently used technique to capture small mammals.
Pseudoryzomys simplex suggests a lack of knowledge about its biology (TALAMONI et al., 2000;BONVICINO et al., 2002;PARDIÑAS et al., 2004) despite the fact that studies involving important information about this species are being developed.In effect, reports about this species are rare due to problems on identification in field, lack of samples and methodological issues.However, new records have extended the occurrence of the species up to 2,000 km from the nearest previous records (PARDIÑAS et al., 2004).Reports of occurrence of P. simplex have been increasing due to the great amount of carcass found in owl regurgitation (mainly Tyto alba) (TALAMONI et al., 2000;PARDIÑAS et al., 2004;TETA et al., 2009;TETA and PARDIÑAS, 2010).Most of those records are concentrated near the region of Rio Paraná, region considered the east limit of this species (PAR-DIÑAS et al., 2004).Bonvicino et al. (2002) commented that P. simplex is a rare species of Cerrado, being restricted to humid environments, wet grasslands vegetation and low altitudes, facts corroborated by Voss and Myers (1991) and Pardiñas et al. (2004).However, the specimen of P. simplex from CMUFLA was captured in cloud forest at 1,550 m high and 50 m from a stream, what excludes the possibility of this species being restricted to low altitude habitat.rios faunísticos de pequenos mamíferos terrestres e/ou reduzida abundância.O objetivo é descrever os locais de ocorrência dessas espécies e, posteriormente, analisar essas localidades apresentando comentários descritivos sobre seus aspectos biológicos.Para isso, além de coletas de espécimes em campo, algumas coleções científicas foram visitadas, pesquisas em bibliografia especializada foram realizadas com o intuito de obter informações sobre as localidades e aspectos biológicos.Akodon lindberghi foi encontrada em cinco locais, Bibimys labiosus foi encontrada em 15, Blarinomys breviceps em 39 e Pseudoryzomys simplex em 13.Cada espécie apresenta características específicas e elas estão incluídas em dois domínios ameaçados, Mata Atlântica e Cerrado.As ocorrências são disjuntas e relacionadas a problemas taxonômicos e metodológicos.Palavras-chave: Novos relatórios.Rodentia.Sigmodontinae.Área de ocorrência.

Figure 1 .
Figure 1.Geographic distribution for A. lindberghi.The numbers refer to the localities on Table 1.Record 5 represents the type locality, Parque Nacional de Brasília, Distrito Federal.Source: Created by the authors

Figure 3 .
Figure 3. Geographic distribution for B. breviceps in Brazil.The numbers refer to the localities on Table 3. Point 8 represents the type-locality Lagoa Santa, MG.Source: Created by the authors information related to P. simplex records.Recently, Patton et al. (2015) increase the number of records out of Brazil.The records include records at northeastern Argentina, western Paraguay, eastern Bolivia and the Pampas del Heath in extreme southeastern Peru.To Brazil, other records include the states of Amapá and Amazonas (see map of distribution to P. simplex in Patton et al. 2015).

Figure 4 .
Figure 4. Geographic distribution for P. simplex in Brazil.The numbers refer to the localities on Table 4. Point 14 represents the type-locality Lagoa Santa, MG.Source: Created by the authors

Table 1 .
Akodon lindberghi records in Brazil.The number of each report corresponds to the localities representation on Figure1.

Table 2 .
B. labiosus records in Brazil.The number of each report corresponds to the localities representation on Figure 2.
Source: Created by the authors Figure 2. Geographic distribution for B. labiosus in Brazil.Numbers refer to the localities on Table 2. Source: Created by the authors

Table 3 .
B. breviceps records in Brazil.The number on each report corresponds to the localities representation on Figure 3.

Table 4 .
P. simplex records in Brazil.The number on each report corresponds to the localities representation on Figure4.