Registered users receive a variety of benefits including the ability to customize email alerts, create favorite journals list, and save searches.
Please note that a BioOne web account does not automatically grant access to full-text content. An institutional or society member subscription is required to view non-Open Access content.
Contact helpdesk@bioone.org with any questions.
Knowledge as to the taxonomic status of enigmatic bat species often is hindered by limited availability of specimens. This is particularly true for aerial-hawking bats that are difficult to catch. One such species, “Hypsugo” joffrei, was originally described in Nyctalus due to its long and slender wings, but subsequently transferred to Pipistrellus, and most recently to Hypsugo, on the basis of morphology. Analysis of newly available material, which more than doubles the known specimens of this taxon, demonstrates that it is morphologically and genetically distinct from all other bat genera. We accordingly describe it as belonging to a new, monotypic genus. We provide a detailed description of its external and craniodental traits, measurements, and assessment of genetic relationships, including barcode sequences to facilitate its rapid identification in future. The new genus belongs to a group that includes the recently described Cassistrellus, as well as Tylonycteris, and its closest relative, Philetor. We also describe the echolocation calls emitted by members of the taxon in different situations, which may facilitate finding them in previously unsampled locations. Based on the new data, the species occurs from Nepal to North Vietnam and China, which suggests that it could be more widespread than previously thought.
We conducted a geometric morphometric analysis to investigate the morphological variation of the golden wolf, Canis lupaster, and to clarify the morphological and taxonomic affinities of different taxa of the genera Canis and Lupulella. We suggest that the variation observed within the complex of Canis lupaster may be incompatible with what would be expected for a single species. We hypothesize that the nominal form C. l. soudanicus is a synonym of Lupulella adusta rather than being part of the golden wolf complex. The subspecies C. l. bea has a generalized jackal morphology (i.e., clusters together with L. mesomelas and C. aureus) and C. l. lupaster occupies an intermediate morphospace position, between jackal-like forms and wolf-like forms. These results contrast with previously published molecular analysis in which mitochondrial data failed to identify differences among golden wolf populations, and nuclear evidence points to the existence of groups that are incompatible with those recovered by morphological analysis. Regarding other jackals, our results depict the absence of morphological overlap between L. m. mesomelas and L. m. schmidti and no differences between putative subspecies of L. adusta. We call attention to the need for more integrative approaches to solve the taxonomic questions in various African Canidae.
Surprising social complexity and variability have recently been documented in several mammalian species once believed to be strictly solitary, and variation in resource abundance may drive this variation in sociality. Wagner et al. (Wagner, A. P., S. Creel, L. G. Frank, and S. T. Kalinowski. 2007. Patterns of relatedness and parentage in an asocial, polyandrous striped hyena population. Molecular Ecology 16:4356–4369) reported unusual space-use patterns among female striped hyenas (Hyaena hyaena) in central Kenya, where pairwise relatedness among females increased with the geographic distance separating them. The authors suggested that this pattern, very rare among mammals, might reflect attempts by females to avoid competition with close relatives for scarce resources in areas of range overlap. Here, we compare those data to new data, documenting genetic relatedness and space use in a previously unstudied wild population of striped hyenas in southern Kenya. We tested hypotheses suggesting that resource abundance and population density affect patterns of genetic relatedness and geographic distance in this species. Our results suggest that higher per capita prey density results in relaxed competition for food, and greater social tolerance among female striped hyenas. A hypothesis suggesting lower population density in the southern population was not supported. Relaxed resource competition also may lead to female–female cooperation in the southern population; we documented for the first time behavioral evidence of den sharing by adult female striped hyenas. Our data indicate that different populations of this little-studied species exhibit behavioral plasticity; in this case, markedly different space-use patterns and patterns of spatial relatedness under different ecological conditions.
Adaptation and evolution of terrestrial vertebrates inhabiting islands have been the topic of many studies, particularly those seeking to identify trends or patterns in body size in mammals, albeit not necessarily in shape, in relation to mainland populations. The spiny pocket mouse, Chaetodipus spinatus, is distributed in the Baja California peninsula and its surrounding islands. Insular populations became isolated ∼12,000 due to changes in sea level; these populations' matrilinear (mitochondrial) DNA shows minor interpopulation variation. We tested the hypothesis that adaptation and evolution in these island populations involve variation in both skull size and skull shape (using geometric morphometrics) relative to mainland populations, rather than only in size as previously assumed. A total of 363 specimens from 15 insular and peninsular populations were used in analysis of the skull length and geometric morphometric analyses. Our findings revealed significant differences related to skull size among population. The skull shape analyses showed two significantly different morphotypes: one for all island specimens and one for all mainland samples. Our analyses support the hypothesis that insular populations may not only vary in size relative to mainland populations, but may also show variations in shape, regardless of differing conditions across islands.
The Serra do Mar Atlantic forest (Brazil) shelters about 15 different species of caviomorph rodents and thus represents a unique opportunity to explore resource partitioning. We studied 12 species with distinct diets using dental microwear texture analysis (DMTA). Our results revealed differences (complexity, textural fill volume, and heterogeneity of complexity) among species with different dietary preferences, and among taxa sharing the same primary dietary components but not those with similar secondary dietary preferences (heterogeneity of complexity). We found three main dietary tendencies characterized by distinct physical properties: consumers of young leaves had low complexity; bamboo specialists, fruit and seed eaters, and omnivorous species, had intermediate values for complexity; grass, leaf, and aquatic vegetation consumers, had highly complex dental microwear texture. Dietary preferences and body mass explained a major part of the resource partitioning that presumably enables coexistence among these rodent species. DMTA was useful in assessing what foods contributed to resource partitioning in caviomorphs. Our database for extant caviomorph rodents is a prerequisite for interpretation of dental microwear texture of extinct caviomorph taxa, and thus for reconstructing their diets and better understanding the resource partitioning in paleocommunities and its role in the successful evolutionary history of this rodent group.
Tail morphology and function vary considerably across mammals. While studies of the mammalian tail have paid increasing attention to the caudal vertebrae, the chevron bones, ventrally positioned elements that articulate with the caudal vertebrae of most species and that serve to protect blood vessels and provide attachment sites for tail flexor musculature, have largely been ignored. Here, morphological variation in chevron bones is documented systematically among mammals possessing different tail locomotor functions, including prehensility, terrestrial propulsion (use for pentapedal locomotion), and postural prop, during which chevron bones are presumably under different mechanical stresses or serve different mechanical roles. Several chevron bone morphotypes were identified along the tail, varying both within and between tail regions. While some morphotypes were present across many or all clades surveyed, other morphotypes were clade-specific. Chevron bone dorsoventral height was examined at key vertebral levels among closely related species with different tail locomotor functions to assess whether variation followed any functional patterns. Dorsoventral height of chevron bones differed between prehensile- and nonprehensile-tailed, prop-tailed and nonprop-tailed, and pentapedal and nonpentapedal mammals. However, small sample sizes precluded rigorous statistical analyses. Distinctions were also qualified among species (not grouped by tail locomotor function), and the utility of metrics for quantifying specific aspects of chevron bone anatomy is discussed. This study offers information about the functional morphology of mammalian tails and has implications for reconstructing tail function in the fossil record.
KEYWORDS: Chiroptera, big crested mastiff bat, duty cycle, echolocation calls, frequency, MaxEnt, Molossidae, social calls, species distribution modeling, vocalizations
The big crested mastiff bat, Promops centralis, occurs in Central and South America, but knowledge of its ecology is limited due to its open space hunting strategy, making captures extremely challenging. Notwithstanding, members of the species produce echolocation calls that are easy to identify. After recording calls of P. centralis 1,500 km away from its known range in Brazil, we hypothesized that the distribution range of this species was probably greatly underestimated. To improve the accuracy of P. centralis' real distribution, we employed acoustic surveys throughout parts of Brazil, conducted after a bibliographic review to gather additional records, and used MaxEnt to model the species' potential distribution. We have found that P. centralis has a much wider distribution in South America than previously thought, adding more than 3.8 million km2 to its former known area. We also describe an unusual vocalization pattern of P. centralis, with individuals emitting at least three very distinct but highly variable calls. This study shows that bioacoustic surveys and species distribution models can complement traditional methodologies in studying species that are difficult to capture, such as P. centralis, potentially contributing to more effective conservation and management plans.
Habitat degradation leads to homogenization of biological communities, often due to the dominance of generalist species over specialists. Yet data as to how life history attributes of specialists vary with such perturbations remain sparse. We compared long-term population dynamics of a specialist trawling bat, the large-footed myotis (Myotis macropus), between two forested catchments. One forest stream was nutrient-enriched from dairy farming in its headwaters and a portion of its surrounding catchment was harvested for timber during the study, while the other was located in primarily undisturbed forest. We caught and banded bats annually at their roosts over 14 years and banded 529 individuals with a 45% recapture rate. The maximum time to recapture was nine years and there was no evidence for transiency in our populations. Mark-recapture analyses allowed for investigation of the dependence of survival on time, sex, and age at marking. Our study spanned extreme El Niño and La Niña weather events, but we found little variation in survival, although recruitment was lower during drought. Mean minimum winter temperature (positive) and rainfall (positive) had weak influences on survival. Survival of adults (∼0.70) and population size of adult females was similar between the two sites, suggesting that neither timber harvesting with retained riparian buffers nor eutrophication from farming influenced survival. Survival of adult males and females was similar, but survival of juveniles was less than half that of adults, probably due to a combination of mortality and dispersal. Survival was three times lower immediately after one of the timber bridges used as a roost fully collapsed. Specializing on aquatic habitats buffered M. macropus from most extreme weather, but there was also evidence for possible mortality and recovery after an intense rainfall and flooding event immediately prior to the study. More frequent intense rainfall predicted with global warming may reduce the species' resilience over time.
Investigating landscape-level movement patterns of migratory animals can be challenging, but this is a major component of some animal's life history and behavior. In particular, bat migration has been difficult to characterize, yet recent research on bat migratory ecology has made major advances. It has been largely accepted that rivers and other linear landscape features may be important migratory corridors for bats during both long- and short-distance migrations. We assessed the migratory behavior of multiple temperate bat species along the Missouri River, a major river corridor in North Dakota, during March through October of 2016–2017. Bat detectors with paired microphones were deployed and oriented parallel to the riverbank. This configuration permitted detection of directional passes of bats, approximately 10–20 m above the microphones and 40 m into the river, which were used as an estimate of migratory behavior. We found the effects of season and species explained less than 2% of the variation of directional passes, indicating an absence of season-specific movement patterns along the studied river corridor. Although our study only assessed a portion of a major river corridor, the results suggest that migratory movements of bats along rivers may not be as straightforward as once thought, highlighting the need for future studies investigating the fine-scaled movement patterns of bats during migration.
Flycatching is relatively uncommon in insectivorous bats, yet members of the family Rhinolophidae constitute over one-half of the documented flycatching species. The Formosan woolly horseshoe bat, Rhinolophus formosae, is among the largest in size and relies primarily on flycatching for foraging. We assessed perch use of flycatching R. formosae in relation to vegetation structure in tropical monsoon forests in southern Taiwan. We located bats using acoustic detectors in forest interior and edge-open forest sites, and measured perch features, dispersion of the nearest trees, and vegetation structure within a 5-m radius of each perch. The same measurements were applied to randomly selected perches in both habitats where bats were not detected. We found no seasonal effects or differences between used and random perches in perch features, dispersion of neighboring trees, or vegetation structure surrounding the perches. Perches used at edge-open forest sites were farther from the perch tree trunk and neighboring trees, and surrounded by larger trees than in forest interiors. In contrast, perches in forest interiors were surrounded by higher shrub and reef layers and greater canopy, shrub, and reef layer cover, than those at edge-open forests. Overall, perches in forest interiors were in more cluttered settings, containing higher vegetation obstacles than edge-open habitats. In both habitats, vegetation obstacles generally increased in a curvilinear manner when moving horizontally and downward from the perch. However, in forest interiors perches used by bats had significantly lower vegetation obstacles horizontally and downwardly and were less cluttered than randomly selected perches. Overall, our results indicate that R. formosae in forest interiors selectively used perches associated with more open space that allows for more maneuverable sally flights and a longer detection range suitable for its exceptionally low constant frequency calls to explore less cluttered environments.
Cave bats have an intimate association with their roosts. Size, structural heterogeneity, and microclimatic conditions are traits of caves known to affect the structure of these assemblages. The effects of the natural and anthropogenic landscape factors around caves on the structure of these assemblages are poorly known, especially in areas with large cave clusters. We assessed the effects of cave size and surrounding landscape attributes on the richness and species composition of cave-roosting bats in 13 caves distributed in two landscapes with large cave clusters in Caatinga dry forests, Brazil. In a 1-km buffer around caves, we obtained 13 internal cave and external landscape variables. Candidate univariate models using generalized linear models were constructed and the Akaike information criterion was used for model selection. The cave size model explained richness and variance in the species composition; larger caves tended to have greater richness and assemblage composition varied depending on the cave size, hence affecting the occurrence of certain species, some of conservation concern (Natalus macrourus, Furipterus horrens). The cave connectivity model affected only the richness; caves located in denser cave clusters had higher richness likely attributed to movement of bats among caves by a more diverse array of species. Both environmental and anthropic variables affected species composition, but differently depending of the landscape context of cave location (protected versus nonprotected area). The extent these landscape variables affected the species composition was due to species-specific responses, and observed in the mean colony sizes of the species shared between the cave systems. All the landscape variables that we tested affected the structuring process of cave-roosting bats assemblages, and evidences that variables found in disturbed karstic landscapes also affect the structure of the assemblage (e.g., large colonies of vampire bats). However, the ubiquitous effect of cave size on both richness and species composition reinforces the critical importance of the roost in the life of these flying mammals.
Fire has shaped much of the Australian landscape, and alterations to natural or historical fire regimes are implicated in the decline of many native mammal species. Time since fire (TSF) is a common metric used to understand vegetation and faunal responses to fire but is unlikely to capture the complexity of successional changes following fire. The New Holland mouse (Pseudomys novaehollandiae), a threatened and declining rodent species native to southeastern Australia, traditionally is considered an early post-fire successional species. Here, we use a 48-year dataset to test whether this posited association with early TSF is upheld, and whether the species' occurrence and abundance are governed by TSF. We find support for a minimal influence of TSF on the species' occurrence, and that while abundance of P. novaehollandiae is explained partly by TSF, considerable uncertainty and variation among fire events and locations limit the usefulness of TSF in informing conservation management strategies. We suggest that it is not helpful to consider the species as early successional and that fire planning for P. novaehollandiae conservation is best considered at a local scale. In addition, we provide guidelines for maximizing individual survival and persistence during and after planned burns.
Animal movement is predicted to be nomadic in areas with low temporal predictability of environmental conditions, but it remains unclear whether the costs of nomadic movement outweigh the benefits received. To examine the spring movement strategy of Mongolian gazelles (Procapra gutturosa) in Mongolia, where predictability of vegetation conditions is relatively low, we identified the type of each movement, evaluated the preferred vegetation conditions for gazelles, and quantified the benefit achieved through each spring movement. The surveyed gazelles continuously preferred areas with intermediate normalized difference vegetation index (NDVI) values from May to July, and spatial and temporal shifts of the distribution of preferred areas explain the long-distance movements of many gazelles in spring. Three movement types, sedentary, linear, and nomadic movement, were identified. The period when benefit varied most greatly among individuals differed between the linear and nomadic movement types. During the spring movement period, the variance of benefit was larger for the nomadic movement type, whereas during the summer it was larger for the linear movement type, suggesting the existence of different movement strategies in the Mongolian gazelle. Linear long-distance movements over a short period in the linear movement type suggest the so-called jumper strategy, whereas other movement patterns might represent the searcher strategy. Benefit loss through movements of individuals in both strategies indicate low interannual predictability of vegetation conditions in the study area, and it would explain the co-existence of multiple movement types or strategies used by Mongolian gazelles in spring.
Vigilance is an important antipredation technique that can be affected by many factors, such as body size and group size. Small animals are more vulnerable than large ones, so the former are expected to behave more vigilantly than the latter. This effect of body size on vigilance may occur inter- or intraspecifically. We studied the vigilance behavior of two sympatric wild ungulates, Tibetan antelopes (Pantholops hodgsonii) and Tibetan gazelles (Procapra picticaudata). Tibetan antelopes, with a body size of 33 kg are much larger than Tibetan gazelles, with a body size of approximately 14 kg. Tibetan antelopes are sexually and body-size dimorphic; that is, males are much heavier than females. Alternately, Tibetan gazelles are sexually dimorphic but the sexes do not differ in weight. Tibetan gazelles scanned their environment more frequently than Tibetan antelopes did. Small female Tibetan antelopes scanned their environment more frequently than males did, whereas male Tibetan gazelles scanned their environment more frequently than females did. Group size did not affect the vigilance of Tibetan gazelle, but its negative effect on the vigilance of male Tibetan antelopes was marginally significant. In female Tibetan antelopes, vigilance in large groups was high probably because of scramble competition and social monitoring. Our results suggested that body mass and group size play an important role in shaping the vigilance of these two rare Tibetan ungulates.
Rodents often act as keystone species in communities and play important roles in shaping structures and functions of many ecosystems. Understanding the underlying mechanisms of population fluctuation in rodents is therefore of great interest. Using the data from a 25-year field survey carried out in Inner Mongolia, China, we explored the effects of density dependence, local climatic factors, and a large-scale climatic perturbation (El Niño–Southern Oscillation) on the population dynamics of the striped hamster (Cricetulus barabensis), a rodent widely distributed in northern China. We detected a strong negative density-dependent effect on the population dynamics of C. barabensis. Rainfall had a significant positive effect on population change with a 1-year lag. The pregnancy rate of C. barabensis was negatively affected by the annual mean temperature in the current year, but positively associated with the population density in the current year and the annual Southern Oscillation Index in the previous year. Moving-window analyses suggested that, with a window length of 12 years, there was a significant interaction between rainfall and density dependence, with increasing rainfall alleviating the negative effect of density dependence. As C. barabensis often causes agricultural damage and can transmit zoonotic diseases to human beings, our results also have implications for pest and disease control.
Tropical forest marsupials exhibit large interannual variation in population sizes, with direct negative density dependence capturing the essential features of their dynamics. However, the demographic mechanisms underlying population growth rate and driving both survival and reproduction are still unclear. We used a 16-year capture-mark-recapture data set for five tropical forest marsupials to test for seasonal and interannual density dependence in survival and recruitment. Hypotheses regarding the effects of exogenous (rainfall and minimum temperature) factors on survival, recruitment, and reproductive parameters (fecundity, litter size, and proportion of reproductive females) were also tested. Population size negatively affected survival in three of five species. High population sizes in a given year reduced survival rates in the following year, with strong detrimental effects on males. Recruitment and proportion of reproductive females were highly dependent on weather variables, and were not affected by previous population sizes (except for Metachirus nudicaudatus). Fecundity (number of female offspring/female) was related negatively to population size only in the black-eared opossum (Didelphis aurita), while litter size was a relatively conservative parameter, largely independent of external conditions. Our analyses indicate that density-dependent survival is the mechanism that regulates population size of tropical forest marsupials, either through a reduction in survival or an increase in emigration rates. This general regulatory mechanism may be common to other marsupials in the Atlantic Forest and other tropical forests.
Social animals may cooperate to gain resources such as food and territory. However, unavoidable conflicts over limited resources frequently occur between group members. Social rank may effectively decrease conflicts within animal social groups, thereby reducing energy consumption and maintaining group stability. In this study, we tested the two factors most often proposed to influence winning a conflict: body size and prior residence. Our results showed that female Asian particolored bats (Vespertilio sinensis) formed near-linear dominance hierarchies. Forearm length was significantly positively correlated with dominance rank in three replicate experiments. In addition, prior residents had significantly higher dominance ranks than intruders of similar body size. These results suggested that both body size and prior residence might affect dominance ranks in female Asian particolored bats.
White-nose syndrome (WNS) has caused large declines in bat populations across eastern North America, making information on demographics of affected species critical to determining their risk for extinction. We used Cormack–Jolly–Seber models to estimate apparent survival rates of hibernating tricolored bats (Perimyotis subflavus) for 5 years in four small abandoned mines in the Ouachita Mountains of Arkansas, located within the WNS endemic area of the United States. Populations in individual mines varied greatly in survival rates, with one mine displaying annual survival rates as high as 0.706 and another as low as 0.101. Differences in survival among bats in different mines could not definitively be attributed to WNS, but may have varied based on a combination of WNS, disturbance, mine climate, and other unknown factors. Further, some hibernacula may have served as temporary winter shelter for young transient males. Sites housing small colonies of hibernating bats may result in high survival rates despite WNS, and protecting these smaller sites may be important for overall species perseverance.
Foraging by animals is hypothesized to be state-dependent, that is, varying with physiological condition of individuals. State often is defined by energy reserves, but state also can reflect differences in nutritional requirements (e.g., for reproduction, lactation, growth, etc.). Testing hypotheses about state-dependent foraging in ungulates is difficult because fine-scale data needed to evaluate these hypotheses generally are lacking. To evaluate whether foraging by caribou (Rangifer tarandus) was state-dependent, we compared bite and intake rates, travel rates, dietary quality, forage selection, daily foraging time, and foraging strategies of caribou with three levels of nutritional requirements (lactating adults, nonlactating adults, subadults 1–2 years old). Only daily foraging times and daily nutrient intakes differed among nutritional classes of caribou. Lactating caribou foraged longer per day than nonlactating caribou—a difference that was greatest at the highest rates of intake, but which persisted even when intake was below requirements. Further, at sites where caribou achieved high rates of intake, caribou in each nutritional class continued foraging even after satisfying daily nutritional requirements, which was consistent with a foraging strategy to maximize energy intake. Foraging time by caribou was partially state-dependent, highlighting the importance of accounting for physiological state in studies of animal behavior. Fine-scale foraging behaviors may influence larger-scale behavioral strategies, with potential implications for conservation and management.
In polygynous mammals, females are expected to bias maternal investment in favor of male calves. The mother should invest more in males to enhance their reproductive success in adulthood, or the males require greater investment as they are bigger and stronger than females. In this study, we used nursing duration to compare the difference in the amount of maternal investment provided by females. We compared differences according to sex of the offspring and the influence of calves' identification by sniffing, using captive giraffes (Giraffa camelopardalis) as a model. Since a high intensity of allonursing (nursing of a nonfilial calf) was reported in giraffes, we also focused on the difference between filial and nonfilial calves. We observed 22 nursing females and 47 suckling calves in four zoological gardens in the Czech Republic from 2007 to 2011. Nursing duration was longer for male calves than for female calves and for calves sniffed by the nursing female regardless whether the calves were filial or nonfilial. We conclude that male calves are more demanding for the amount of investment received and they are more successful in this effort than female calves. Since females provided investment in the same way to filial and nonfilial calves, selection for higher demand for investment by male than by female offspring should be important for their future development. Our results also demonstrate the importance of sniffing for the identification of the suckling calf by the female.
We assessed the effects of cub age, litter size, and sex, on body mass (BM), absolute and relative growth rates (AGR, RGR), opening of ears and eyes, and deciduous teeth eruption from 129 cubs of American black bears (Ursus americanus) born at Virginia Tech's Black Bear Research Center. Specific ages, related to maternal food consumption, and litter size, best described BM, AGR, RGR, and ear and eye development. Overall, newborns weighed ∼0.44 kg at birth and increased ∼9-fold by ∼14 weeks. Twins were greater in BM than single cubs and triplets. Single and triplet cubs had higher AGR and RGR than twins after mothers resumed food consumption post-hibernation. Newborns displayed RGR > 3.5% that decreased until den emergence (RGR < 3.5% after emergence). RGR differed among litter sizes, particularly after den emergence. Ear and eye opening occurred concurrently at ∼44 days of age, while teeth erupted ∼10 days later. Single cubs experienced delayed development of these organs compared to other litter sizes. Postnatal developmental differences between black bears and other carnivores likely stem from strategies allowing black bears to minimize energy expenditure during the gestational period when hibernating.
Animals that depend on water sources in dry environments must balance their water demands with predation risk. In settings of water scarcity, predators may strategically exploit prey's dependence on water; prey may adjust their use of water sources either spatially or temporally to avoid overlapping with predators. To examine the spatiotemporal dynamics of predators and prey at water sources, we studied the use of semipermanent waterholes in the dry season by red-fronted lemurs (Eulemur rufifrons), a primate species that exhibits flexible circadian activity patterns and inhabits a dry deciduous forest in western Madagascar. We hypothesized that lemurs avoid predators in their spatiotemporal use of waterholes. We analyzed the patterns of camera trap activations at waterholes by red-fronted lemurs and their two main predators: fossa (Cryptoprocta ferox) and Madagascar harrier hawks (Polyboroides radiatus). We found that red-fronted lemurs were unlikely to use waterholes at times of day when predators were commonly present, and that the distributions of times of waterhole use differed between red-fronted lemurs and each of their predator species. Red-fronted lemurs frequently used waterholes that were also used by predators within the same week in part because the predators used a variable set of water resources. In this system, predators did not appear to exploit waterholes for the high density of red-fronted lemurs attracted to them, but instead likely used waterholes primarily to meet their own water demands. Our findings suggest that when predators and prey share water sources, prey may adjust their behavior to reduce their risk of overlap with predators, including through avoidance of indirect cues of predation, such as waterholes at particular times of day.
Although several mammals impregnate their fur with environmental odors, a phenomenon termed scent anointing or rubbing, the functional relevance of this behavior often is unclear. One theory is that scent anointing could be a form of scent matching with environmental odors to signal competitiveness and home range occupation. In this study we presented giant pandas with a range of odors to determine whether scent matching could provide a functional explanation for scent anointing in this species. We found that only a musk-based perfume elicited significantly more scent-anointing and scent-marking behavior than control. Males were also significantly more likely to scent-anoint and scent-mark than females. A preference for anointing, but not scent marking, when presented with peppermint (an insecticide) also was revealed. Our results suggest that giant pandas differentially scent-anoint with foreign odors to signal home range occupation, and possibly to repel ectoparasites. We also highlight how chemical signaling of resource-holding potential is likely to play an important role in determining competitive interactions between adult male giant pandas.
Mark A. Ditmer, Amanda M. McGraw, Louis Cornicelli, James D. Forester, Peter J. Mahoney, Ron A. Moen, Seth P. Stapleton, Véronique St-Louis, Kimberly VanderWaal, Michelle Carstensen
Anthropogenic habitat change and moderating climatic conditions have enabled the northward geographic expansion of white-tailed deer, Odocoileus virginianus, and of the parasitic nematode (meningeal worm) it carries, Parelaphostrongylus tenuis. This expansion can have consequences in dead-end host species for other ungulates because meningeal worm reduces health, causes morbidity or direct mortality, and has been attributed to population declines. In northeastern Minnesota, which marks the southern extent of the bioclimatic range for moose (Alces alces), the moose population has declined more than 50% in the last decade, with studies detecting P. tenuis in 25–45% of necropsied animals. We assessed the factors that most commonly are associated with meningeal worm infection by linking moose movement ecology with known P. tenuis infection status from necropsy. We outfitted moose with GPS collars to assess their space use and cause-specific mortality. Upon death of the subject animal, we performed a necropsy to determine the cause of death and document meningeal worm infection. We then created statistical models to assess the relationship between meningeal worm infection and exposure to hypothesized factors of infection risk based on the space use of each moose by season. Predictors included land cover types, deer space use and density, environmental conditions, and demographics of individual moose (age and sex). Moose with autumn home ranges that included more upland shrub/conifer, and individuals with high proportions of wet environments, regardless of season, had increased infection risk. In contrast, the strongest relationships we found showed that high proportions of mixed and conifer forest within spring home ranges resulted in reduced risk of infection. The spring models showed the strongest relationships between exposure and infection, potentially due to moose foraging on ground vegetation during spring. By incorporating movement of moose into disease ecology, we were able to take a top-down approach to test hypothesized components of infection risk with actual spatial and temporal exposure of individual necropsied moose. The probability of infection for moose was not influenced by deer density, although deer densities did not vary greatly within the study area (2–4 deer/km2), highlighting the importance of also considering both moose space use and environmental conditions in understanding infection risk. We suggest management strategies that use a combination of deer and land management prescriptions designed to limit contact rates in susceptible populations.
The combination of morphometrics, phylogenetic comparative methods, and open data sets has renewed interest in relating morphology to adaptation and ecological opportunities. Focusing on the Caviomorpha, a well-studied mammalian group, we evaluated patterns in research and data sharing in studies relating form and function. Caviomorpha encompasses a radiation of rodents that is diverse both taxonomically and ecologically. We reviewed 41 publications investigating ecomorphology in this group. We recorded the type of data used in each study and whether these data were made available, and we re-digitized all provided data. We tracked two major lines of information: collections material examined and trait data for morphological and ecological traits. Collectively, the studies considered 63% of extant caviomorph species; all extant families and genera were represented. We found that species-level trait data rarely were provided. Specimen-level data were even less common. Morphological and ecological data were too heterogeneous and sparse to aggregate into a single data set, so we created relational tables with the data. Additionally, we concatenated all specimen lists into a single data set and standardized all relevant data for phylogenetic hypotheses and gene sequence accessions to facilitate future morphometric and phylogenetic comparative research. This work highlights the importance and ongoing use of scientific collections, and it allows for the integration of specimen information with species trait data.
This article is only available to subscribers. It is not available for individual sale.
Access to the requested content is limited to institutions that have
purchased or subscribe to this BioOne eBook Collection. You are receiving
this notice because your organization may not have this eBook access.*
*Shibboleth/Open Athens users-please
sign in
to access your institution's subscriptions.
Additional information about institution subscriptions can be foundhere