Volume 78, Issue 3

We reviewed case studies in female Japanese macaques engaged in social and spatial emigration. In such instances, animals leave their natal group and remain alone or in a small group, transfer to another group, or join extra-group males to establish a new group. Since 1953, at least 34 emigration cases (and at least 78 females) have been reported from eight study sites of five provisioned and three wild populations in Japan. In most cases, female emigration occurred 1) when food conditions warranted the move due to either a decrease in the artificial feeding of provisioned populations or to a seasonal deterioration in the food environment of wild populations and/or 2) when group structure was disturbed via a drastic change in size or the disappearance of adults. In most cases, subordinates were the ones who emigrated. Unlike the case in other primate species, an influx of extra-group males never led to female emigration to avoid infanticide. These suggest that decreases in per capita foraging success within the group and loss of support from kin and group males were probably principle factors motivating emigration by females. In response to environmental deterioration, females emigrate and settle within new location/range within same habitat type.

The white-lipped peccary ( Tayassu pecari ) is a large ungulate species with an extensive distribution across South and Central America. As such, it is a key game species for forest communities throughout its range. It is also considered an “ecosystem engineer”, having a significant impact on forest structure and function. The species has recently been upgraded to “vulnerable” owing to decreasing population trends. Many studies report evidence of strong population fluctuations, but data are lacking from long-term surveys. Our study documents population fluctuations in French Guiana based on both line transect and hunting monitoring in hundreds of sites across the country, over 15 consecutive years. Our results show that white-lipped peccary populations drastically decreased in French Guiana between 2000 and 2010, and that low-density periods have repeatedly occurred during the past decades. White-lipped peccaries were absent from the Nouragues Reserve during 4 years of camera trapping monitoring (2006–2010) and probably from most of the country. However, more recent data suggest that the species is becoming more common again in French Guiana, supporting the hypothesis of cyclic population fluctuations.

Foraging sites are important for the survival of animals. Individuals cue on characteristics of the forest that offer enough food resources and also provide safety. During June and July of 2009 and 2010, we studied northern and southern Amazon red squirrels ( Sciurus igniventris , S. spadiceus ) to determine what forest characteristics were associated with feeding sites. We examined habitat use at three levels: vegetation community where feeding sign was located, site characteristics of the forest immediately surrounding the feeding sign, and the tree exhibiting feeding sign. We measured the site characteristics inside a 10-m radius circular plot, the physical characteristics of the tree exhibiting feeding sign, and the same variables at random locations for comparison. Because there is lack of knowledge about these squirrels, we also conducted focal observations to study their behavior. Squirrels use mainly high and low restinga and selected Astrocaryum and Attalea palm trees that were taller and larger compared with random locations. Squirrels used all vertical strata of the forest, and the main behaviors observed were travel and forage. Behaviors occurred similarly across the day but differed by vertical strata. Although squirrels used vegetation communities different than available and selected for tree characteristics, site characteristics did not appear to be important in contrast with other tree squirrel species.

Introduced brown hares are present across the distribution range of maras, which are endemic to Argentina’s open steppes. Food competition with exotic herbivores could be partially responsible for declines in mara populations. Diets of sympatric hares and maras were compared to detect dietary overlap according to food availability. Diets and availability were estimated using microhistological analysis and point-quadrat transects, over four seasons. Horn’s index estimated dietary overlap, Kruskal-Wallis ANOVA detected significant differences, and permutational multivariate analysis of variance (PerMANOVA) determined the multivariate response to factors. Grasses prevailed among available items and in both diets. Plant cover and richness increased in summer and forbs in spring. High dietary overlap decreased in autumn-winter, when hares ate more forbs and tall shrubs and less low shrubs than maras. Interspecific overlap was higher inside a protected area with higher food diversity, more forbs, and low shrubs. Both herbivores shifted to different foods as availability decreased. When forbs declined, they were less eaten by maras than hares. Broader habitat use allows hares to search for preferred forbs farther away than maras. The more adaptive hare could become a stronger competitor in impacted environments. Better food availability inside than outside the protected area is a feeding advantage for the coexistence of these herbivores.

We examined the changes in the amount of nitrogenous substances in 1497 stomachs of four small forest rodent species [yellow-necked mouse ( Apodemus flavicollis ), wood mouse ( Apodemus sylvaticus ), bank vole ( Clethrionomys glareolus ), and common vole ( Microtus arvalis )] using near-infrared reflectance spectroscopy (NIRS). The amount of nitrogenous substances varied from 9.31% to 65.39% of dry matter. Significant differences were observed between species, with both Apodemus species displaying higher variability and higher mean nitrogenous substance content in the diet compared with M. arvalis . Results for C. glareolus were intermediate for both variability and mean value. In general, concentrations of nitrogenous substances were higher in the diet of juveniles. Differences in diet composition (or ratio of nitrogenous substance) in different biotopes were only demonstrated for C. glareolus. Moreover, C. glareolus diet varied within the same biotope over different years. Clethrionomys glareolus was the only species to display differences in diet between males and females, with males having higher nitrogen concentrations. These findings are in agreement with the C. glareolus broad dietary niche. This study confirmed the suitability of NIRS for determining nitrogenous substance content in the diet of small rodent species.

Mammary number determines the nursing ability of a female and is an important factor in the evolution of litter size. We studied the variation in the number of nipples and the mean litter size in the fat dormouse Glis glis from northern Iran. Iranian dormice have on average more nipples (mean, 12.57±1.024) than their counterparts from northern Italy (11.25±0.85) and Slovenia (10.22±0.50). Different nipples are responsible for the variation in mammary numbers between populations: inguinal nipples vary in Slovenia, and abdominal nipples vary in Italy and Iran. We estimated the litter size in the Iranian fat dormouse to be equal to 7.85±0.89, which is evidently more than that reported in populations from northern Moravia (mean, 5.0) and Slovenia (mean, 5.8). The fact that fat dormice from Iran display higher mammary number and have more litters than their conspecifics from Europe conforms to the prediction of Gilbert’s empirical “one-half rule.” Owing to its highly specialized reproductive profile, the fat dormouse can adjust its fitness only by an increase of litter size, which in turn makes greater use of available nipples. We suggest that a greater nipple count may be selectively advantageous in the evolutionary perspective and that the Iranian population displays the most derived mammary number in the species.

A near-threatened species, the maned wolf’s ( Chrysocyon brachyurus ) range extends from central Brazil, northern and eastern Bolivia, and southeastern Peru to the southeast of the Gran Chaco ecoregion and adjacent scrubland in Argentina. Rural domestic dogs under ownership may pose threats to maned wolves as reservoir hosts of multiple pathogens. A serologic survey of rural domestic dogs and maned wolves was conducted to document exposure to canine pathogens in southeastern Santiago del Estero, Argentina, with a parallel questionnaire of knowledge, attitudes, and perception of local villagers in relation to maned wolves. The three maned wolves examined had evidence of exposure to canine adenovirus, canine distemper virus, canine parvovirus, Leptospira interrogans spp., and Dirofilaria immitis . Dogs had very high seroprevalence for Neospora caninum and canine coronavirus (67%), canine adenovirus (59%), D. immitis (58%), canine distemper virus (57%), Toxoplasma gondii (33%), and L. interrogans spp. (20%). Antibodies for canine parvovirus, Brucella canis and Trypanosoma cruzi were rare or absent. Multiple logistic regression analysis showed that dog seroprevalence was not significantly associated with age, sex, and function for any of the pathogens investigated. The frequency distribution of seroreactivity to specific pathogens per dog was highly aggregated. Villagers considered that illegal trade, hunting, vehicular collisions, and interactions with dogs were the most serious local threats for maned wolves. The multiple threats faced by the maned wolf populations in southeastern Santiago del Estero suggest that their populations are unlikely to remain viable unless specific protection measures are taken.

The margay ( Leopardus wiedii ) is a small felid currently facing critical population declines in many regions throughout its Central–South American range. This species is thought to be the most arboreal of the New World felids, which has led to concern that it may be especially sensitive to deforestation and habitat destruction. Due to the margay’s elusive nature, little is known about its ecology and natural history. In the present study, a camera trap survey was used to investigate whether margay abundance and activity patterns are correlated to vegetational structure in a mid-elevation forest in the eastern Andes of Ecuador. Structural habitat variables were measured at each camera station to assess whether these factors were predictive of margay camera “trap” success. The data show that canopy cover, average distance to nearest trees, and distance to forest edge were significant predictors of margay trap success, although compositional analysis indicated that the highest margay presence was in areas of 51–75% canopy cover rather than the very densest locations. These results highlight the importance of curbing habitat destruction and deforestation as part of efforts to reverse the margay’s declining population trend and protect its habitat.

Patterns of geographic variation in cranial characters of the American black bear ( Ursus americanus ) were examined for 11 localities in the western US and Canada. Forty-four dimensions were recorded from skulls of 290 (149 males, 141 females) adult (≥4.5 years old) animals using digital calipers. Results showed that males are generally larger than females and the degree of sexual-size dimorphism for characters among localities is relatively consistent. Most averages (84.1%) of mean values across characters varied from 7.0% to 18.0%. The majority (90.9%) of character ranges (difference between highest and lowest value for a trait at each locality) of mean values for sexual dimorphism varied from 5.0% to 14.0%. Overall, there was no significant statistical difference in the degree of sexual dimorphism across localities in 43 of 44 characters. Measurements for males were significantly correlated with those of females for 38 of 44 characters. Results indicated that the level of sexual-size dimorphism remained relatively low and constant across localities. No statistically significant relationship existed between degree of sexual-size dimorphism and selected environmental variables. Although overall causes for levels of sexual differences in morphological features of black bears remain uncertain, bioenergetics appears to be a determining factor associated with sexual-size dimorphism in black bears.

This study aims to describe landscape evolution in two contiguous ecoregions with different land use intensity, to assess changes in small mammal assemblages. Rodent remains in pellet samples from barn owls were used to estimate the attributes of rodent assemblages. Two major biomes were considered in this study, a mosaic of wetlands (Delta and Paraná Islands ecoregion) and a mosaic of grasslands and cultivated fields (Pampa ecoregion). Environmental characterization was based on the analysis of satellite images and weather data. Fourteen rodent species in 28 sampling sites were identified, totaling 7645 prey items. Linear combinations of variables that characterized the landscape explained 66.6% of variation in the composition of rodent assemblages. A positive linear relationship between rodent diversity and the number of different patches was found in the Pampa. Our results suggest that landscape disturbances caused by agricultural intensification favor the increase of generalist and competitively subordinated species. In turn, changes in rodent diversity at the Paraná Delta were negatively associated with the percentage of water-covered area and the number of patches. The hydrological regime of this ecoregion acts as a filter for species establishment, restricting the richness of the rodent assemblages.

Talpine moles are reported to nest at the same site for periods longer than their known longevity. The present study verifies experimentally in situ that during such long-term nesting, the inhabitants of the nest change, with the new inhabitant constructing its own nest if the existing nest has been removed. The principal methods involved removal of both the nest and inhabiting mole from the nesting site, the site that had been located by observing the fruiting of the mushroom species Hebeloma radicosum . This treatment was followed by observation of refruiting of the mushroom at the same site; refruiting indicated renesting by another mole. Verification was made at three sites in the cool temperate forests of central Japan where three talpine species live. At two of the sites, the inhabiting Euroscaptor mizura mole was replaced by another E. mizura mole. At the third site, a Mogera wogura mole was replaced by a Mogera imaizumii mole. The causes and circumstances for such persistent nesting are discussed, with emphasis on habitat-cleaning symbiosis.

We carried out a pilot study about the influence of the domestic goat Capra hircus on the feeding ecology of the Iberian ibex Capra pyrenaica in the Peneda-Gerês National Park (PGNP, Portugal). We mapped the grazing areas of domestic goat flocks and determined their stocking rates in two mountains of PGNP, Gerês and Amarela, and we investigated the diets of both ungulates using fecal microhistology in an area where they partially overlapped during spring and summer. Diet composition, ligneous diversity, and ligneous trophic niche were compared seasonally. Although differences in ligneous components were observed, results revealed a considerable diet overlap mainly due to graminoids consumption, especially during autumn and spring. This suggests that direct or indirect foraging competition between the goat species should not be discarded if they spatially concur. Results also emphasized distinct summer feeding strategies of C. pyrenaica in the area, and the influence of cattle ( Bos taurus ) and horses ( Equus caballus ) were hypothesized. We recommend removing feral goats from the mountain environment and monitoring grazing areas of domestic flocks. Estimates of ecological carrying capacity and future diet studies should include cattle, horses, and improvement of herb identification.

The likelihood of interspecific interactions between wild primates is particularly high for species with overlapping territories. The sharing of the same or similar ecological niches can result in competition for space or resources, which can lead to agonistic encounters such as predator-prey interactions. Here, we report the observation of an abduction and potential case of predation of an infant howler monkey ( Alouatta guariba clamitans ) by an adult male capuchin monkey ( Sapajus nigritus ) in Minas Gerais, Brazil. Evidence of capuchin monkeys’ predation of other smaller sympatric primate species has already been reported, as well as description of agonistic interactions between capuchin and howler monkeys, but none as drastic as the case described here. Although we were not able to collect evidence after the abduction, we discuss the events leading up to it and present arguments in favour of the case of interspecific predation or infanticide.

The broad-clawed shrew Cryptotis griseoventris Jackson, 1933, is poorly known ecologically and behaviorally because distributional records are relatively scarce. Here, we provide new records based on 11 specimens deposited in mammal collections, more than 50 years since the last confirmed record. Historical records and specimens are reexamined and discussed. We suggest that C. griseoventris occurs in a small area (<5000 km 2 ) above 2100 m dominated by pine oak and cloud forests in Los Altos de Chiapas, Mexico, and is likely endangered due to habitat deforestation. We also describe the humerus, a useful structure to delimit species and reconstruct phylogenetic relationships within the genus Cryptotis . The morphology of their humerus corroborates its taxonomic relatedness with the Cryptotis goldmani species group and yields a more comprehensive knowledge of the ecology and evolution within this group.

Dental microwear has been shown to reflect diet in a broad variety of fossil mammals. Recent studies have suggested that differences in microwear texture attributes between samples may also reflect environmental abrasive loads. Here, we examine dental microwear textures on the incisors of shrews, both to evaluate this idea and to expand the extant baseline to include Soricidae. Specimens were chosen to sample a broad range of environments, semi-desert to rainforest. Species examined were all largely insectivorous, but some are reported to supplement their diets with vertebrate tissues and others with plant matter. Results indicate subtle but significant differences between samples grouped by both diet independent of environment and environment independent of diet. Subtle diet differences were more evident in microwear texture variation considered by habitat (i.e., grassland). These results suggest that while environment does not swamp the diet signal in shrew incisor microwear, studies can benefit from control of habitat type.