Volume 84, Issue 3

In high-density populations, the adults of the Japanese serow ( Capricornis crispus ) defend their home ranges against same-sex intruders, and a male’s territory typically overlaps with those of one to three females. We examined the spatial organization and mating behavior of the species in a low-density population by direct observation and radio-tracking over a 4-year period. The home range size of both males and females was more than 4 times larger than that reported in high-density populations. Adult females had ranges that overlapped little, even though they were never observed in agonistic interaction. In contrast, adult males had ranges that overlapped largely except in their core areas, and appeared to be tolerant on encounters, suggesting they did not defend their whole range as a territory. Although males’ ranges overlapped with multiple female ranges, males were only observed following a single female during the mating season. These findings suggest that males directly defended a female rather than a territory, and that the mating system is monogamous. The Japanese serow’s social organization would therefore vary according to ecological conditions.

Small mammal communities in the Neotropics are composed largely of sigmodontine rodents. However, many questions regarding these communities remain unanswered, especially those pertaining to fine-scale sympatry and habitat selection. To address this, we examined sigmodontine community structure and vegetation in the western margin of the Upper Paraná Atlantic Forest and the southwestern-most extent of the Cerrado (CE) (an extensive South American savanna ecoregion) of Paraguay. Vegetation classifications were derived from satellite imagery combined with maps based on extensive ground-based surveys. The three most abundant species ( Akodon montensis , Hylaeamys megacephalus , and Oligoryzomys nigripes ) were found most often in microsympatry with conspecifics, and were negatively associated with other species. Akodon montensis was associated with high forest (HF), and H. megacephalus with bamboo understory (BU), whereas O. nigripes did not exhibit a habitat preference. The first two species’ distributions within the landscape were found to be driven primarily by habitat selection, and O. nigripes by a behavioral response (avoidance) to the presence of the other two species. Moreover, habitat influences whether or not a particular species associates with, or avoids, conspecifics or other species.

Harvest mouse detectability represents a real issue for surveys, as usual ground-trap monitoring is known to fail to detect this species, especially in summer. The present study proposes to test ground versus aerial live-trapping efficiency for harvest mouse in summer, with a trapping design using paired ground and aerial traps over a 2-year survey in a reedbed. Over 10,720 trap-nights, the harvest mouse represented 85% of the 1078 small mammals captured, and it was the only species among five which was more often trapped above ground (n = 702) than on the ground (n = 213). Capture probability was significantly higher in aerial than in ground traps, with a slightly positive effect of leaf litter and, surprisingly, a negative effect of dense vegetation cover. Following these results, recommendations are made for harvest mouse monitoring.

Some phyllostomid bats modify leaves of certain plant species in order to build tents as daytime roosts. Most tent-roosting members of the Artibeus and Dermanura genus have a widespread geographic distribution; nevertheless, there are few reports regarding roost architecture. This is the first report in Mexico of boat/apical tents built by the pygmy fruit-eating bat Dermanura phaeotis .

The Sumatran striped rabbit ( Nesolagus netscheri Schlegel, 1880) is the least known lagomorph in the world. This paper describes the first record of a young N. netscheri that was offered for sale (the size is approximately 52–56% of the adult), together with an adult, by a social media group in February 2018. The rabbits were reportedly obtained from the Dempo mountain, South Sumatra. Compared to previous descriptions of N. netscheri , the Dempo mountain specimens have longer ears (47–52 mm vs. 34–50 mm), shorter tails (9–15 mm vs. 17 mm) and shorter hindfeet (60–65 mm vs. 67–87 mm). The threats to N. netscheri are revisited and discussed.

During a systematic survey of the small mammals in the relatively unexplored north-western regions of the Tibetan plateau in India, we captured and identified the desert hamster Phodopus roborovskii using molecular phylogenetic methods. We also provide revised distributional estimates for this species using niche modelling (Maxent and 19 bioclimatic variables), taking into account sampling bias. We evaluated suitable habitats for the species, identifying regions in the Trans-Himalayas that may harbour this species. This study improves the knowledge of the desert hamster’s range and is a new record and an addition to the Indian sub-continental mammalian fauna, ~750 km southward extension from its known range.

The genus Castor first appeared in the Palaearctic region during the Late Miocene, while the current species, Castor fiber , is widely accepted to have emerged in the Early Pleistocene. In the Last Glacial Maximum (Late Pleistocene), the beaver disappeared from most of the Western Palaearctic, only surviving in a few relic areas including the south-eastern Alpine Chain as shown by new data. After the subsequent extended repopulation in the warmer phases of the Lateglacial and in the early Holocene, the species once again disappeared locally from several countries, including Italy, between the 17th and the 20th centuries. Direct or indirect persecution by humans seems to be the main cause of beaver extinction in Europe. In Low Medieval Italy, it is more likely that the disappearance of the beaver between the 16th and 17th centuries was due to habitat alteration and human population pressure. Numerous reclamations have been carried out since the late Middle Ages, mostly in the easternmost area of the Po Valley, the last beaver refuge in Italy. Eurasian beaver was common in the northern and widespread in the central part of Italy, but always absent in southern Italy, probably due to unfavourable hydrological conditions of watercourses in the latter.

We studied the enlargement of the upper third molar (M3), with respect to the upper second molar in sigmodontine rodents, the largest subfamily of living cricetids. M3 is enlarged in extant and extinct members of at least six tribes (Andinomyini, Euneomyini, Oryzomyini, Phyllotini, Reithrodontini and Sigmodontini), all of them also sharing hypsodonty, planate crowns and overall dental simplification in the context of Sigmodontinae. Enlargement is expressed in four ways, including simplification or modest complication of occlusal design on a single plane. M3 enlargement in sigmodontines is primarily associated with increasing herbivory rather than strictly with phylogeny, and thus presents a classic example of evolutionary convergence.

This paper presents unique data on the reproductive behavior of the rare giant armadillo ( Priodontes maximus ), including gestation, inter-birth intervals, number of offspring and parental care. It also describes a potential non-parental infanticide. The study used telemetry, camera traps and track observations for over 7 years in a 300-km 2 area in the central Brazilian Pantanal. Females with young were recorded 5 times. Reproductive events did not appear to be seasonal. A 5-month gestation period was estimated. Parental care is long, as the offspring is completely dependent on its mother’s milk until 6–8 months of age. Weaning was estimated to occur at 11–12 months, but the offspring continued to be dependent on its mother’s burrows until 18 months old. Three births were recorded over a 6-year period for one individual. The offspring from the first birth recorded was killed at 4 weeks of age in a potential infanticide, but 7 months after the first birth, a second offspring was born. A third birth was recorded 3 years after the second birth. Results from this study suggest that the population growth rate of giant armadillos is very low and the species can therefore easily be locally extirpated.

Pigmentation polymorphism occurs in many mammals but is considered rare in natural populations. Here, we report the first record of pigmentation polymorphism in a Neotropical squirrel, Guerlinguetus ingrami , at a private reserve in southern Brazil. The number of records for leucistic squirrels was approximately half that for brown squirrels. We also tested the differences in activity patterns between the leucistic and the brown squirrels. Both phenotypes were diurnal, but there was temporal segregation between the two. Further studies are needed to elucidate the occurrence of leucism in G. ingrami , and the possible ecological and behavioral outcomes.

Akodon oenos , a nominal form with type locality in northern Mendoza province, Argentina, has an intricate taxonomic history. Recently, it was considered a junior synonym of Akodon spegazzinii on the basis of morphological similarities of one individual captured in southern Mendoza with specimens belonging to the type series of A. oenos , plus the genetic similarity of that single specimen with representatives of A. spegazzinii . We compared specimens of the Akodon boliviensis species group recently captured in Mendoza with the type series of A. oenos and series of A. spegazzinii from northwestern Argentina. We conducted an analysis of molecular markers (cytochrome- b gene) and quantitative morphological studies (comparisons of skull measurements). Our results showed that: (1) all sequenced specimens of the A. boliviensis group from Mendoza form a monophyletic clade closely related to A. spegazzinii ; (2) contrary to previous hypothesis, specimens of Akodon from Mendoza are morphologically distinctive in size and shape of the skull, from A. spegazzinii ; and (3) within the A. boliviensis species group, specimens from Mendoza are distinctive. We argue that the synonymy of A. oenos under A. spegazzinii must await further studies, including molecular markers other than mitochondrial and samples of DNA sequences from topotypical specimens of A. oenos .