Felipe Bortolotto Peters

Geographic distribution and food habits of Leopardus tigrinus and L. geoffroyi (Carnivora, Felidae) at their geographic contact zone in southern Brazil

The objective of this study is to define the geographic distribution of Leopardus tigrinus and L. geoffroyi in one of the few regions of South America where they co-occur, the state of Rio Grande do Sul (RS), in southernmost Brazil. We compiled 133 records for both species and constructed a distribution map, which shows sharp geographic segregation between them. Leopardus tigrinus was found to be associated more with forested ecoregions in the northern part of the state, while L. geoffroyi records were mainly associated with open habitats of the Pampas biome in southern RS. We present data on the diet of these two species that indicate trophic niche separation between them in this region of geographic contact. Our results thus suggest that these species exhibit ecological partitioning with respect to habitat and prey, and that these factors may influence the observed pattern of limited spatial overlap in this region.

Feeding habits of Molina's hog-nosed skunk, Conepatus chinga (Carnivora: Mephitidae) in the extreme south of Brazil

Feeding habits of the Molinas hog-nosed skunk, Conepatus chinga (Molina, 1782) in the extreme south of Brazil. We analyzed 60 stomachs of road-kills of C. chinga in the extreme south of Brazil. The contents revealed 808 prey parts, including invertebrates (frequency of occurrence - FO = 96.7% and relative abundance - RA = 94.7%), vertebrates (FO = 18.3% and RA = 2.8%) and plants (FO = 31.7% and RA = 2.3%). We identified 18 kinds of food, including the invertebrate order Coleoptera which showed the highest FO (86.7%) and RA (75.2%). Other important orders were Orthoptera (FO = 35% and RA = 10.4%) and Araneae (FO = 41.7% and RA = 4%). The combination of occurrence and abundance of the preys consumed allowed classifying C. chinga as an omnivorous with a predominance of insects, especially Coleoptera, consuming other invertebrates, vertebrates and plants in smaller numbers. Behavioral and morphological adaptations of C. chinga favor the predation of insects, which are preys that offer low physical resistance and are available in all terrestrial environments.

Ixodes spp. (Acari: Ixodidae) ticks in Rio Grande do Sul state, Brazil

ABSTRACT Among the 251 described species of ticks from the genus Ixodes, only eight were previously reported in Brazil, Ixodes amarali, Ixodes aragaoi, Ixodes auritulus, Ixodes fuscipes, Ixodes loricatus, Ixodes luciae, Ixodes paranaensis and Ixodes schulzei. Of those species, I. loricatus is considered commonly found, whereas I. auritulus and I. aragaoi were registered just one time in Rio Grande do Sul (RS) state, Southern Brazil. This paper aims to update the Ixodes species occurring in RS through the investigation of the ixodofauna of small rodents. Data from 314 wild rodents were analyzed from nine municipalities of Pampa biome and five from the Atlantic Rainforest in RS. Rodents belonging to the following species were infested by Ixodes spp. ticks: Akodon azarae, Akodon montensis, Akodon paranaensis, Akodon reigi, Calomys laucha, Delomys dorsalis, Deltamys kempi, Holochilus brasiliensis, Oligoryzomys flavescens, Oligoryzomys nigripes, Oxymycterus nasutus, Scapteromys tumidus (Cricetidae) and Cavia aperea (Caviidae). The tick identification was performed based on morphological dichotomous keys, their updates and by molecular techniques. Considering the ticks from the rodents and those collected directly from the environment, 34 specimens of Ixodes spp. were collected. Our results improved to five the list of Ixodes species that occur in RS: I. loricatus, I. auritulus, I. aragaoi, I. fuscipes and I. longiscutatus. Moreover, the finding of I. longiscutatus increases to nine the number of Ixodes species in Brazil. The occurrence of two species of the Ixodes ricinus complex (I. aragaoi and I. fuscipes) highlights the potential impact of Ixodes spp. ticks on public health.

Trophic relationships of sympatric small carnivores in fragmented landscapes of southern Brazil: niche overlap and potential for competition

Abstract Between 2000 and 2010, digestive tracts collected from carnivore carcasses found in southern Brazil were analyzed to determine the frequency and proportion of items constituting the diets of each species. Material was collected and analyzed from 194 animals of 10 species: Cerdocyon thous, Lycalopex gymnocercus (Canidae), Procyon cancrivorus (Procyonidae), Galictis cuja (Mustelidae), Conepatus chinga (Mephitidae), Leopardus colocolo, Leopardus geoffroyi, Leopardus guttulus, Leopardus wiedii, and Puma yagouaroundi (Felidae). Most of these species are sympatric, which makes them potential competitors when sharing, to a greater or lesser degree, the same resources. The food niche breadth was relatively narrow, demonstrating that even generalist species, such as the crab-eating raccoon, used food resources rather unequally. An extensive overlap (>90%) in food niches was found among the cat species, the grison, and the Pampas fox, which had diets based on rodents. Crab-eating raccoons occupied a different food niche, based on aquatic or semiaquatic prey and fruits. Conepatus chinga was unique in exploiting arthropods and insect larvae as basic dietary items.

Unraveling Deep Branches of the Sigmodontinae Tree (Rodentia: Cricetidae) in Eastern South America

Neotropical cricetid rodents of the subfamily Sigmodontinae constitute an incredibly diverse and ubiquitous clade of mammals in South America. In spite of recent advances in sigmodontine systematics, a variable collection of genera from eastern South America with no clear tribal affiliations and well-differentiated morphologies has been pervasive in most classification attempts, being generally listed as Sigmodontinae incertae sedis. Here, we assess the phylogenetic relationships of these incertae sedis genera based on supermatrix and multispecies coalescent analyses of a multilocus molecular dataset (one mitochondrial and five nuclear loci) for 76 genera, calibrated with ten fossil-based node dates. Both analytical approaches provided concordant and unprecedented resolution of suprageneric clades within the large Oryzomyalia clade (constituted by most sigmodontine genera), recovering a natural group constituted by the genera Wiedomys , Wilfredomys , and the Atlantic Forest endemics Juliomys and Phaenomys - here redefined as the Wiedomyini tribe - and a sister-relationship between this group and the tribe Abrotrichini. The enigmatic spiny rodent genus Abrawayaomys was recovered as sister to Akodontini in three of four analyses, but pending higher support. Morphological comparisons performed among the four wiedomyine genera highlighted a number of shared external, cranial, and dental similarities useful to emend the tribe diagnosis, such as the presence of chromo-genetic fields associated with the muzzle, pinnae, and rump, the long and narrow rostrum flanked by shallow and narrow zygomatic notches, and the asymmetrically divided procingulum of M1, among other characters. Molecular dating coupled with fossil evidence suggests Wiedomyini as one of the oldest sigmodontine tribes with a late Miocene autochthonous origin in eastern South America, highlighting the relevance of this region as an ancient cradle of sigmodontine lineages.

Trophic ecology of sympatric small cats in the Brazilian Pampa

Information about resource partitioning among small cat species that live in sympatry in South America is fairly incomplete. Knowledge about feeding habits is essential for understanding the role of these predators in the environment, the impact on prey populations, and potential competition among themselves and with other carnivores. This study aimed to describe and compare the diet of four sympatric small cats in the grasslands of southern Brazil. We analysed the stomach contents of 37 Geoffroy’s cats (Leopardus geoffroyi), 27 margays (Leopardus wiedii), 14 pampas cats (Leopardus colocola), and 20 jaguarundis (Herpailurus yagouaroundi) obtained as road kill in the Brazilian Pampa in southern Brazil. Small mammals were the most representative class consumed by all cats, followed by Aves, Reptilia, and Amphibia. Some items, such as rodents Cavia aperea, Akodon sp., Oligoryzomys sp. and Passeriformes were consumed by all cat species. Niche overlap varied widely, from 10% (margay x jaguarundi) to 92% (jaguarundi x pampas cat). Niche breadth indicated that jaguarundi were the most specialized of the cats (Bsta = 0.24) in this region, with a diet closely associated to C. aperea. Margay consumed more items associated with arboreal behaviour than other cat species, but consumed more terrestrial items than arboreal ones. The pampas cat consumed mostly terrestrial species associated with open fields. Geoffroy’s cat consumed mammals found in a diversity of habitats, indicating high ecological flexibility. Species with more similarity in diet such as jaguarundi and pampas cat probably present temporal segregation in activity. In conclusion, despite their habitat and diet similarities, these four species explore distinct microhabitats by foraging different prey groups, what favor them to live in sympatry.

New records of Cuniculus paca (Rodentia: Cuniculidae) in a temperate grassland dominated landscape of the Pampa region of Brazil and Uruguay

Abstract Cuniculus paca is considered locally threatened in some parts of its range mainly because of hunting pressure and habitat loss. The species is widely distributed in South and Central America. Agouti’s distribution in Brazil is broad, although there is no information on its occurrence in the Northeast region and in the western part of Rio Grande do Sul state. The species presents a marginal distribution in northeastern Uruguay. Here, we describe 16 new records of the species in the Pampa region, including the western part of Rio Grande do Sul state, Brazil and Uruguay, expanding the C. paca known distribution.

Mammalia, Chiroptera, Molossidae, Molossus rufus É. Geoffroy, 1805: Distribution extension

This paper presents seven new records of occurrence of Molossus rufus for the state of Rio Grande do Sul, Brazil, three from the Atlantic Forest Biome and four from the Pampa Biome. The southern limit of the known geographical distribution of this species in Brazil is extended by 159 km.