Ricardo Tadeu Santori

Mammals of Serra da Bocaina National Park, state of Rio de Janeiro, southeastern Brazil

Here we present a commented list of mammals registered in the Serra da Bocaina National Park. Three field trips (February, 2010, and May and July, 2011) were accomplished along the RJ-165 highway in the Municipality of Paraty, State of Rio de Janeiro, Brazil. Forty-eight species belonging to nine orders were recorded. The local mammal fauna could be considered diverse and rich, with some species regarded as biological indicators of habitat quality. Endangered and rare rodent species like Blarinomys breviceps , Juliomys rimofrons , and Thaptomys nigrita were captured. Road and hunting impacts on mammals are discussed.

Comparative gross morphology of the digestive tract in ten Didelphidae marsupial species

Natural diets of Didelphidae species vary in the amounts of invertebrates, fruits and small vertebrates eaten. We investigated the digestive morphology of ten species of didelphid marsupials varying in food habits. The purpose was to describe and to compare the shape and relative size of the digestive tract portions among species studied and relate them to food habits. The form of the gastrointestinal tract in this family is simple, with a unilocular stomach, small intestine, large intestine and caecum. Caluromys philander was the species with highest association between digestive tract measurements and its frugivorous habits. However, although its caecum is morphologically distinct from the other species, the relative length is small when compared to the more faunivorous Metachirus nudicaudatus. Stomach length of Philander frenata is related to a more carnivorous diet, while large intestine length of Didelphis aurita is related to its omnivore diet. The digestive tract measurements of the other species appear to be related with a variable degree of morphological differentiation from a generalized form related to omnivory toward a more carnivorous diet. Great caecum relative size distinguished Metachirus nudicaudatus from the most other species and its relationship with diet is not well understood.

Locomotion in Aquatic, Terrestrial, and Arboreal Habitat of Thick-Tailed Opossum, Lutreolina crassicaudata (Desmarest, 1804)

Abstract The reasons Lutreolina crassicaudata is always captured in close proximity to water are not clear. We investigated locomotory behavior and performance in swimming, running, climbing, and jumping of L. crassicaudata. One adult male was videotaped in the laboratory while swimming, walking on the ground and on a horizontal tube 1.2 m from the ground, climbing a tree trunk angled 45°, and jumping gaps between supports. The locomotor cycles in these different activities were described by speed, stride length, stroke or stride frequency, time of power and recovery phases or stance and swing phases, and by displacement of points on the animal. L. crassicaudata employed a quadruped paddling gait in swimming. Swimming speed was similar to that of terrestrial didelphids, but stroke frequency and buoyancy ability were more similar to those of the water opossum. Different gaits were used for locomotion in each habitat type and we conclude that L. crassicaudata cannot be considered a specialized species for aquatic locomotion.

Water Absorption of the Fur and Swimming Behavior of Semiaquatic and Terrestrial Oryzomine Rodents

Abstract Locomotion in land and water requires different adaptations, hence semiaquatic mammals must deal with conflicting demands of the 2 environments. Semiaquatic rodents of the tribe Oryzomyini are considered semiaquatic mostly based on habitat use and morphology, but locomotory specializations were not yet determined for most species of the group. We compared water absorption of the fur and swimming behavior between 2 species of oryzomyine water rats (Nectomys) and 2 terrestrial species of Cerradomys. We used adult rodents captured in the wild but acclimated to laboratory conditions. Water absorption rate was determined by the relative increase in body mass after a 5-min swimming session. Animals were videotaped swimming in an aquarium to determine gaits, body posture, maneuverability, and speed. Water absorption rate was significantly lower in semiaquatic species, with no significant difference between sexes. Bipedal paddling was the more frequently used gait by all 4 species, but semiaquatic species were faster and maintained a more hydrodynamic body posture, with a short gliding phase during the gait cycle. Only semiaquatic species were capable of floating effortlessly, and used the swimming bound, a gait similar to the half bound of terrestrial locomotion. Submerged swimming was the fastest swimming gait, used by 1 terrestrial and 1 semiaquatic species. The better performance during bipedal swimming of semiaquatic water rats was related to the improved buoyancy provided by reduced water absorption of the fur, which seemed to represent an important adaptation to move in the water without compromising locomotion on land.

Breeding of Philander frenata (Didelphimorphia, Didelphidae) in captivity

Data on the reproductive biology and laboratory management of Philander frenata are presented here. Sensory contact before pairing increased breeding success and reduced aggression between pairs. Gestation period was 13–14 days, with a post-lactation oestrous. Births occurred only between August and February. Mean litter size at birth and at weaning was 5.5 (SD=2.4) and 4.0 (SD=1.9), respectively. Sex ratio at birth was statistically biased toward males. The timing of weaning was established at between 70 and 80 days old, with the young weighing from 24 g to 49 g.

Notes on Food Habits of Armadillos (Cingulata, Dasypodidae) and Anteaters (Pilosa, Myrmecophagidae) at Serra Da Capivara National Park (PiauÍ State, Brazil)

Abstract This is one of the few studies on food habits of armadillos and anteaters in the Caatinga, Brazil. Our aim was to describe food items found in fecal and stomach samples of six species (Dasypus novemcinctus, D. septemcinctus, Euphractus sexcinctus, Myrmecophaga tridactyla, Tamandua tetradactyla, Tolypeutes tricinctus) at the Serra da Capivara National Park, Piauí State, Brazil. For most species, invertebrates — especially Isoptera and Hymenoptera — were the main food source. Seeds were found in samples of most species studied, including M. tridactyla and T. tetradactyla.

Diet of Tonatia bidens (Chiroptera, Phyllostomidae) in an Atlantic Forest area, southeastern Brazil: first evidence for frugivory

Abstract The greater round-eared bat Tonatia bidens has a varied diet, consuming mostly insects, although it also feeds on small terrestrial vertebrates, such as rodents and birds. In 2008–2009, we expanded the knowledge of this species’ feeding ecology by analyzing the diet of a T. bidens population in an Atlantic Forest fragment in southeastern Brazil. Food remains found in day shelters and feeding roosts included insects, birds, mammals and fruits. Insects, Lepidoptera, Blattodea, Coleoptera and Orthoptera, were the main component of the diet. There was a preferential consumption of the soft parts of insects and vertebrates, possibly because these parts are more easily digested and are the most nutritious. This first evidence of fruit consumption is also discussed. This analysis indicates that T. bidens has a more general diet than previously reported.

Aquatic locomotion of the terrestrial opossum Didelphis aurita (Didelphimorphia, Didelphidae) using undulatory swimming mode

Abstract This note reports the first record of undulatory swimming mode by the black-eared opossum Didelphis aurita. The record was made in a stream running through the Atlantic Rain Forest in Southern Brazil. After the individual was released, it dove into the stream to escape, swimming using undulation of its trunk and tail. In general, terrestrial mammals use similar gaits to walk and swim. The lateral undulation of the trunk and tail observed during the diving of D. aurita was similar to that seen in quadruped diagonal gaits in terrestrial habitats, but swimming without use of fore and hind limbs is a behavior unique to aquatic locomotion, increasing the locomotor repertoire of this species.

An additional record for the rare Black-Shouldered Opossum Caluromysiops irrupta Sanborn, 1951 (Didelphimorphia: Didelphidae) in Northwestern Brazil

Caluromysiops irrupta Sanborn, 1951 is a poorly known didelphid marsupial species, currently known from nine localities in south-central and western Amazonia. Only two records of C. irrupta were known from Brazil. Here we report the third record, in Rondonia state, northwestern Brazil. The specimen was sighted in a well-preserved forest area, in the Parque Estadual Guajara Mirim, Guajara Mirim, Rondonia. Although this record does not represent a distribution extension, it represents an additional record for a very poorly known species.