Mammal Assemblages Research Articles

The influence of fine‐scale topography on detection of a mammal assemblage at camera traps in a mountainous landscape

Changes in topography, such as terrain elevation and slope, are an important source of landscape complexity influencing the ecology of animals, particularly in mountainous landscapes. In such landscapes animals navigate changes in elevation and slope in their daily movement. Despite the importance of topographic variation, studies of animal ecology in mountainous landscapes tend not to explicitly consider those effects on species detection. We deployed a broad‐extent, coarse resolution camera‐trapping system across a landscape with considerable complexity and quantified the influence of topographic variables on detection probability conditional on occurrence for multiple mammal species. Specifically, we examined the fine‐scale effects of terrain steepness and topographic position (i.e. ridges, mid‐slopes or valleys) on detection probability for 14 mammal species at camera‐traps. We found that detection probability increased on gently sloping terrain for six species and decreased on the steepest slopes sampled for three of these species and three additional species. Among four other mammal species, detection probability changed according to local topographic position though the directionality of these responses varied among these species. Several species, primarily meso‐carnivores as well as larger‐bodied species, like mule deer and black bears, were more detectable on gentle slopes than flat terrain. This pattern suggests that many species may use moderately steep terrain for the resources or heterogeneity they provide. Topographic position had comparatively less effect on species detection probabilities, suggesting that this variable does not have a strong effect on fine‐scale space use of animal species in mountainous regions. These relationships suggest that researchers should consider local terrain when siting camera traps in mountainous landscapes and analyzing survey data from such landscapes. Studies that compare the detection of mammal species at cameras deployed in close proximity will improve our understanding of fine‐scale topographic effects on mammal movement and detection.

Community structure of medium-large mammals across a tree plantation cycle in natural grasslands of Uruguay

In temperate South America, the conversion of natural grasslands into crops and exotic tree plantations, such as with Eucalyptus sp., has reached outstanding levels, especially in the Río de la Plata Grasslands. The cycle of Eucalyptus plantations for pulp production is a very dynamic phenomenon; however, most of the studies on the impacts on biodiversity have been static and focused on the mature stage of the plantation. We studied the mammal assemblage in a grassland afforestation landscape of Uruguay to address how mammals respond to habitat complexity variation across the plantation cycle and landscape characteristics. We installed 26 camera traps for two years in four different age stages of Eucalyptus plantations and native habitats to assess mammals’ richness, composition, and intensity of habitat use. We registered 16 mammal species, 13 native and three exotics, with a sampling effort of 19,136 camera-nights. Of these species, 11 were found in the Eucalyptus plantations but with significant variability during the production cycle. Only one species was recorded at the beginning (0–2 years) of the cycle and four species at the end (8–10 years). But at intermediate ages (2–4 years), when vegetation complexity resembles a native forest structure, species richness was maximum (11 species) in the plantations and relatively close to forest richness (14 species). Species composition was also determined by habitat structure, but it was further modulated by landscape features, particularly the proximity to native forests and landscape heterogeneity. Our results demonstrated that asynchronous plantations promote spatial heterogeneity that favors mammal diversity in afforested landscapes, but for grassland mammals, additional conservation management measures are needed.

Composition of terrestrial mammal assemblages and their habitat use in unflooded and flooded blackwater forests in the Central Amazon.

Several forest types compose the apparently homogenous forest landscape of the lowland Amazon. The seasonally flooded forests (igapós) of the narrow floodplains of the blackwater rivers of the Amazon basin support their community of animals; however, these animals are required to adapt to survive in this environment. Furthermore, several taxa are an important source of seasonal resources for the animals in the adjacent unflooded forest (terra firme). During the low-water phase, the igapó becomes available to terrestrial species that make use of terra firme and igapó forests. Nonetheless, these lateral movements of terrestrial mammals between hydrologically distinct forest types remain poorly understood. This study tested the hypothesis that the attributes of the assemblages (abundance, richness, evenness, and functional groups) of the terrestrial mammals in both these forest types of the Cuieiras River basin, which is located in the Central Amazon, are distinct and arise from the ecological heterogeneity induced by seasonal floods. After a sampling effort of 10,743 camera trap days over four campaigns, two for the terra firme (6,013 trap days) and two for the igapó forests (4,730 trap days), a total of 31 mammal species (five were considered eventual) were recorded in both forest types. The species richness was similar in the igapó and terra firme forests, and the species abundance and biomass were greater in the terra firme forest, which were probably due to its higher primary productivity; whereas the evenness was increased in the igapós when compared to the terra firme forest. Although both forest types shared 84% of the species, generally a marked difference was observed in the composition of the terrestrial mammal species. These differences were associated with abundances of some specific functional groups, i.e., frugivores/granivores. Within-group variation was explained by balanced variation in abundance and turnover, which the individuals of a given species at one site were substituted by an equivalent number of individuals of a different species at another site. However, the occupancy was similar between both forest types for some groups such as carnivores. These findings indicate that seasonal flooding is a relevant factor in structuring the composition of terrestrial mammal assemblages between terra firme and floodplain forests, even in nutrient-poor habitats such as igapós. The results also highlight the importance of maintaining the mosaic of natural habitats on the scale of the entire landscape, with major drainage basins representing management units that provide sufficiently large areas to support a range of ecological processes (e.g., nutrient transport, lateral movements and the persistence of apex predators).

Wildlife overpass structure size, distribution, effectiveness, and adherence to expert design recommendations.

It is now well evidenced that wildlife crossing structures paired with exclusion fencing reduce wildlife vehicles collisions while facilitating wildlife connectivity across roadways. Managing animal mortality and subpopulation connectivity is crucial to successful species and landscape stewardship. Highway mitigation projects are large economic investments that remain on the landscape for many decades. Governments and planning agents thus strive to balance cost and benefit to build cost-effective structures with the greatest positive impact on local wildlife and motorists. Ideal dimensions of overpasses and underpasses vary by species, but scientists generally suggest that overpasses for large mammals should be approximately 50 m wide. Optimal width also depends on structure length, with longer structures requiring additional width. Accordingly, experts have suggested a width to length ratio of 0.8. We sought to assess how these recommendations manifested in practice-where agencies use this information to design and build structures while also balancing cost and logistical challenges-and the degree to which built structures conform to current recommendations. We identified 120 wildlife overpasses across the world that were constructed to reduce the negative impacts of roads. Using a novel measurement technique, we analyzed the dimensions of these 120 overpasses located in North America, Europe, Asia, and Oceania. The average width of the wildlife overpasses was 34 m. Most wildlife overpasses located in North America and Europe did not meet their respective dimensional expert guidelines. We investigate reasons explaining the non-compliance and provide recommendations for future overpass designs. Building on previous evidence showing that wider overpasses have increased crossing rates, we examined crossing rates for multiple large mammal species across 12 overpasses located in western North America. We qualitatively observed that wider North American overpasses (40-60 m), in or near compliance with expert guidelines, were associated with a more diverse set of species use and had nearly twice the average crossing rates when compared to non-compliant, narrow North American overpasses. In reviewing various studies from around the world, we conclude that wide overpasses (~50 m) continue to present ecologically sound and cost-effective solutions for decreasing the barrier of roadways, especially when targeting width-sensitive species and large assemblages of mammals. Future studies, however, are encouraged to further explore the specific instances when underpasses and narrower overpasses present more cost-effective ecological solutions, or how these structures can complement wide overpasses in successful wildlife crossing systems.

Solving a ‘puzzle’. The global 4.2 ka Bond Event at El Mirador cave (Sierra de Atapuerca, Burgos, Spain) and the importance of small mammal taphonomy to the interpretation of past environments and their climatic controls

The regional climatic context in which Chalcolithic (MIR5) and Bronze Age (MIR4) levels from El Mirador cave (Sierra de Atapuerca, Burgos, Spain) are framed is affected by the 4.2 ka cal. BP event, a global event defined as a cooling and aridification phase. Previous works based on palaeoenvironmental inferences indicate conflicting results regarding the possible impact of the event on vegetation and small mammals from MIR5. Pollen record illustrates a possible aridification episode that could match with the 4.2 ka cal. BP event, while the signal of this event is not clearly recorded in the small mammal assemblage, which indicates more humid environmental conditions than pollen record. Taphonomic analyses confirmed that the small mammal assemblages from MIR4 and MIR5 are the result of predation, supporting the involvement of European eagle owls ( Bubo bubo) in its formation. This avian raptor shows a marked preference for hunting animals living in the more open and wetter parts of their hunting range. Likewise, spontaneous specialisation on abundant prey species could also be observed under certain environmental conditions. This characteristic behaviour of eagle owls may have provided the contradictory results observed between the small mammal assemblage and palynological evidence. Nonetheless, taphonomic analyses also provided information about climatic conditions and fluctuations along time. The low incidence of manganese coatings and carbonate crusts deposits in small mammal bone remains from MIR5 support the presence of arid conditions during the formation of this level, which agreed with the aridification phase probably related to the 4.2 ka Bond Event inferred by palynological data from MIR5. These results provided a more robust conclusion about the paleoenvironmental contexts during the formation of Chalcolithic and Bronze Age levels at El Mirador cave.

Small mammal taphonomy and palaeoecological Holocene interpretations in the Andean piedmont (southern Mendoza province, Argentina)

ABSTRACT Salamanca cave (southern Mendoza province) is in the Andean piedmont, a transitional area in which small mammal communities may have been affected by climatic pulses. The site yields three archaeological components covering from the early to the late-Holocene with a mid-Holocene occupational and sedimentological hiatus. Taphonomic analyses of the small mammal assemblages indicate that barn owls (Tyto furcata) were the main accumulation agent, ensuring accurate palaeoecological inferences. Taxonomic composition of the site shows the dominance of Eligmodontia sp. followed by Thylamys pallidior, Phyllotis cf. P. vaccarum-pehuenche and Ctenomys sp., all of them indicative of shrubland and bare ground habitats. Palaeoclimatic inferences indicate a trend to warmer temperatures from the lower to the upper component with a slight increase in humidity in the middle component. This humid pulse is also supported by post-depositional taphonomic processes. The taxonomic structure and abundance of small mammals do not show deep changes amongst the three archaeological components, following the general trend observed in other archaeological sites from the Pampean region, southern Mendoza province and the arid and semi-arid zones of north Patagonia, in which changes in the taxonomic composition of small mammal communities are almost absent since Pleistocene–Holocene transition to late Holocene.

Erinaceomorpha and Soricomorpha (Mammalia) of the Miocene Tagay fauna (Olkhon Island, Lake Baikal, Eastern Siberia): A preliminary report

The current paper is a preliminary attempt to describe the eulipotyphlan fauna from the Early/Middle Miocene (MN5) Tagay-1 locality. Our results reveal one hedgehog species, Parvericius cf. P. buk (Erinaceinae), one desman species, Desmaninae gen. et sp. indet. (Desmaninae), three mole species, Quyania sp., Urotrichini gen. et sp. indet. and Yanshuella cf. Y. primaeva, one Desmanodon species (Talpidae incertae sedis) and three shrew species, Plesiosorex sp., Heterosorex sp. and Miosorex sp. (Plesiosoricidae, Soricidae). Therefore, the Tagay fauna is composed of European, Asian and North American genera. The desman remains are very similar to Late Miocene representatives of European Archaeodesmana, and represent the first Miocene record of Desmaninae in northern Asia. Our small mammal assemblage of the Tagay-1 section allows us to confirm the earlier reconstruction of the local palaeoenvironmental conditions as linked habitats such as closed forest and open ecotonal habitats preferred by ground-dwelling hedgehogs, shrew moles and shrews, and subterranean groups such as digging moles. The presence of desmans indicates flowing waters and probably wetland areas that would also be the favoured habitat of shrews.

The impact of a run‐of‐the‐river hydroelectric dam on a non‐volant small‐mammal assemblage in Brazilian Amazonia

AbstractThere are few scientific studies evaluating the impact of the loss of wetlands on the banks of tropical rivers on assemblages of small non‐flying mammals. To understand the possible deleterious effects of hydroelectric construction in tropical forests on this group of mammals, we used data from 2 years of monitoring carried out during the period before the filling of a hydroelectric plant reservoir in the Brazilian Amazon, and related them to vegetation, soil and topography. We captured 659 individuals of 20 small‐mammal species. The species assemblage composition in the flooded areas was a subset of species that occurred in both floodable and non‐floodable areas, and only one species was captured exclusively in the flooded area. Species composition was influenced by the proportion of sand, by soil nutrient concentration and distance from water bodies. We conclude that there is no evidence that the flooding of low‐lying areas along the Madeira River would negatively affect the assemblage of non‐flying small mammals in the short term because the remaining areas have similar assemblages of small mammals as those destined for flooding. Whether the area lost will be important for population dynamics will depend on the conservation of the remaining areas.

Mammalian diversification bursts and biotic turnovers are synchronous with Cenozoic geoclimatic events in Asia

Asia's rich species diversity has been linked to its Cenozoic geodiversity, including active mountain building and dramatic climatic changes. However, prior studies on the diversification and assembly of Asian faunas have been derived mainly from analyses at taxonomic or geographic scales too limited to offer a comprehensive view of this complex region's biotic evolution. Here, using the class Mammalia, we built historical biogeographic models drawn on phylogenies of 1,543 species occurring across Asia to investigate how and when the mammal diversity in Asian regions and mountain hotspots was assembled. We explore the roles of in situ speciation, colonization, and vicariance and geoclimatic events to explain the buildup of Asia's regional mammal diversity through time. We found that southern Asia has served as the main cradle of Asia's mammal diversity. Present-day species richness in other regions is mainly derived from colonization, but by the Miocene, in situ speciation increased in importance. The high biodiversity present in the mountain hotspots (Himalayas and Hengduan) that flank the Qinghai-Tibetan plateau is a product of high colonization instead of in situ speciation, making them important centers of lineage accumulation. Overall, Neogene was marked by great diversification and migrations across Asia and surrounding continents but Paleogene environments already hosted rich mammal assemblages. Our study revealed that synchronous diversification bursts and biotic turnovers are temporally associated with tectonic events (mountain building, continental collisions) and drastic reorganization of climate (aridification of Asian interior, intensification of Asian monsoons, sea retreat) that took place throughout the Cenozoic in Asia.

Tropical forest loss impoverishes arboreal mammal assemblages by increasing tree canopy openness.

Landscape-scale deforestation poses a major threat to global biodiversity, not only because it limits habitat availability, but also because it can drive the degradation of the remaining habitat. However, the multiple pathways by which deforestation directly and indirectly affects wildlife remain poorly understood, especially for elusive forest-dependent species such as arboreal mammals. Using structural equation models, we assessed the direct and indirect effects of landscape forest loss on arboreal mammal assemblages in the Lacandona rainforest, Mexico. We placed camera traps in 100 canopy trees, and assessed the direct effect of forest cover and their indirect effects via changes in tree basal area and canopy openness on the abundance and diversity (i.e., species richness and exponential of Shannon entropy) of arboreal mammals. We found that forest loss had negative indirect effects on mammal richness through the increase of tree canopy openness. This could be related to the fact that canopy openness is usually inversely related to resource availability and canopy connectivity for arboreal mammals. Furthermore, independently of forest loss, the abundance and richness of arboreal mammals was positively related to tree basal area, which is typically higher in old-growth forests. Thus, our findings suggest that arboreal mammals generally prefer old-growth vegetation with relatively low canopy openness and high tree basal area. However, unexpectedly, forest loss was directly and positively related to the abundance and richness of mammals, probably due to a crowding effect, a reasonable possibility given the relatively short history (~40years) of deforestation in the study region. Conversely, the Shannon diversity was not affected by the predictors we evaluated, suggesting that rare mammals (not the common species) are the ones most affected by these changes. All in all, our findings emphasize that conservation measures ought to focus on increasing forest cover in the landscape, and preventing the loss of large trees in the remaining forest patches.

Geology and lithology of the Tagay-1 section at Olkhon Island (Lake Baikal, Eastern Siberia), and description of Aplodontidae, Mylagaulidae and Sciuridae (Rodentia, Mammalia)

Excavations along the Tagay-1 section shed light into the composition of small mammal assemblages of the Tagay site. The present paper focuses on the geology and geomorphology of Olkhon Island, the lithology and fossil evidence along the Tagay-1 section and descriptions of the aplodontid, mylagaulid and sciurid rodents. The described fossils are isolated teeth of four taxa, Ansomys sp. (Aplodontidae), Lamugaulus olkhonensis Tesakov and Lopatin, 2015 (Mylagaulidae), Sciuridae indet. and Spermophilinus debruijni nov. spec. (Sciuridae). The archaic tooth pattern of these rodents suggests an age around the Early/Middle Miocene transition.

Taphonomy and biochronology of the Late Pleistocene mammalian fauna at Baolai cave, in Bubing Basin, southern China

ABSTRACT This paper reports a mammalian fauna collected from the excavation of Baolai cave, southeast of Bubing Basin, in 2004. The fauna mainly consists of extant species and only a few typical members of ‘Ailuropoda-Stegodon fauna’ (Stegodon, Ailuropoda and Rhinoceros). According to results of the U-series dating from flowstones overlying and below the fossil beds (54–24 Ka), the Baolai fauna represents the mammalian assemblage in the Late Pleistocene. Compared with the faunas of Middle and Late Pleistocene in southern China and Southeast Asia, extant species dominate the Baolai fauna, mostly consistent with modern fauna of southern China during the Holocene. Modern fauna emerged later in southern China than in Southeast Asia, presenting successive characteristics. Significant bias for small or tiny fossils in Baolai cave reveals a special taphonomic process. Baolai cave is located at the same horizontal level as Upper Wuyun cave and Ganxian cave which yield Middle Pleistocene deposits with mammalian fossils. However, the Baolai fauna is much younger. Based on the gnawing marks on tooth roots, rodents may be the main taphonomic agent, or the fossils were brought in by flow-water through the karstic system above.

Differentiation and seasonality in suitable microsites of seed dispersal by an assemblage of omnivorous mammals

In endozoochorous seed dispersal, the ecological characteristics of each disperser determine the quantitative and qualitative aspects of the dispersal mechanism. To understand the role of different frugivores in multispecies seed dispersal networks, it is necessary to focus on the community structure and investigate where in the landscape seed deposition occurs. The aim of this research was to assess the quantitative and qualitative aspects of a mammalian endozoochorous seed dispersal network in a temperate forest ecosystem and identify the seasonal dispersal niche of each member of the assemblage. We hypothesized that differences among dispersers and seasons would occur in (H1) the proportion of scats that contain seeds, seed abundance in scats, and the number of seed species dispersed per scat, and in (H2) the probability of dispersing seeds to suitable microsites for germination of each species and seed abundance. We also hypothesized (H3) that the microhabitat variables of deposition sites would vary among dispersers, and (H4) that complementary structures would occur in terms of dispersers, dispersed species, and deposition sites. From summer (June–August) to autumn (September–November) in 2003 and 2004, we collected scats of five mammalian frugivorous species and recorded eight microhabitat variables at each deposition site in central Japan. We recorded the presence and number of seeds in scats and identified all seed at the species level. We considered a deposition site as suitable when the habitat type (interior forest, treefall gap, forest edge, and outside the forest) at a deposition site matched the microhabitat required for the for the dispersed species to germinate and survive as seedlings. A total of 341 scats containing seeds of 16 fleshy-fruited species were collected. Among these, 213 (62.5 %) scats were dispersed to suitable habitats (summer: 68.8 %, autumn: 54.8 %). We found that the seed abundance in the scat varied among dispersers and was higher in autumn (H1–2). The probability of dispersing seeds to suitable microsites switched among dispersers from summer to autumn (H2). The distinctive microhabitat variables and variation in microhabitat at deposition sites differed among dispersers across seasons (H3). Disperser-plant and disperser-deposition site networks were specialized and modular in structure compared to random networks during both seasons, but there was a less nested structure in summer compared to autumn (H4). The five mammal species showed differences and seasonality in seed dispersal niches. Because of these differences, these mammal species may play redundant and complementary roles in the seed dispersal network.

The remains of a large cercopithecid from the Lower Pleistocene locality of Karnezeika (southern Greece)

ABSTRACTThe Lower Pleistocene Karnezeika locality, lies in the Peloponnese, southern Greece, and its fauna corresponds to the Middle Villafranchian biochronological unit (MN17). The recovered mammal assemblage includes, among others, a few remains of a large Cercopithecid. Herein, we describe this material, including an upper second molar, a partially preserved proximal radius and, possibly, an upper first incisor. The teeth show advanced stages of wear but retain their typical papionin characters, such as a strong lingual cleft and four bilophodont cusps in the molar. The general morphology and wear pattern of the teeth rules out the possibility that the remains belong to the genus Theropithecus, while the general size of the corresponding material excludes the possibility of a Macaca representative as well. On the contrary, the studied material better fits the size range of Paradolichopithecus. Even though this genus is likely represented in the Villafranchian of Europe by a single species, Par. arvernensis, the scarcity of the studied material imposes reservations and thus the Karnezeika papionin is referred at the moment to cf. Paradolichopithecus sp. As in the rest of Europe, the Paradolichopithecus record is rare in Greece, having been found in only two localities, Vatera and Dafnero. Despite its scarcity, the new material from Karnezeika indicates a wide distribution of this important taxon in the Greek peninsula.

Discovery of a fossil dwarf antelope outside of Africa and its implications for the late Miocene ecosystem in the northeast margin of the Tibetan Plateau

As a typical dwarf antelope, the extant Nesotragus is confined to shrub areas of open woodlands and forests in Eastern and Central Africa. Molecular phylogenetic reconstructions reveal that Nesotragus, along with Aepyceros (impala), represents the earliest crown group of Antilopinae. However, to our knowledge, fossils in relation to Nesotragus have to date not been found. Here, we report the recent discovery of a fossil dwarf antelope, Linxiatragus dengi gen. et sp. nov., from the early Late Miocene (10–9 Ma) of the Linxia Basin, adjoining the NE Tibetan Plateau. This is the first report of a fossil dwarf antelope outside of Africa and prior to Pliocene. Phylogenetic reconstructions confirm that L. dengi belongs to the clade of extant Nesotragus. Morphometric studies further suggest that the cranial morphology of Linxiatragus is intermediate between the extant Nesotragus and Gazella. A microwear study indicates that unlike extant Nesotragus, L. dengi was possibly a grazer rather than a browser, revealing that extant Nesotragus are secondarily small, an adaptation to a concealing habitat. l. dengi, as well as some other taxa (e.g., Diceros gansuensis) occurring in the NE margin of the Tibetan Plateau in the early Late Miocene, suggests a relatively arid and open regional paleoenvironmental condition, which mimicked the African Savannah woodlands ecosystem. This ecological implication is consistent with the relatively open lands in the Linxia Basin prior to the tectonic uplift of the NE Tibetan Plateau, as indicated by geological evidence. These findings might provide a new interpretation for the origin and migration of modern Sub-Saharan African Savannah mammalian assemblage through the land-bridge connecting Arabia and Asia after their hard-collision.

Snapshot of the Atlantic Forest canopy: surveying arboreal mammals in a biodiversity hotspot

AbstractThe Atlantic Forest of South America supports a rich terrestrial biodiversity but has been reduced to only a small extent of its original forest cover. It hosts a large number of endemic mammalian species but our knowledge of arboreal mammal ecology and conservation has been limited because of the challenges of observing arboreal species from ground level. Camera trapping has proven to be an effective tool in terrestrial mammal monitoring but the technique has rarely been used for arboreal species. For the first time in the Atlantic Forest, we obtained data on the arboreal mammal community using arboreal camera trapping, focusing on Caparaó National Park, Brazil. We placed 24 infrared camera traps in the forest canopy in seven areas within the Park, operating them continuously during January 2017–June 2019. During this period the camera traps accumulated 4,736 camera-days of footage and generated a total of 2,256 photographs and 30-s videos of vertebrates. The arboreal camera traps were able to detect arboreal mammals of a range of body sizes. The mammal assemblage comprised 15 identifiable species, including the Critically Endangered northern muriqui Brachyteles hypoxanthus and buffy-headed marmoset Callithrix flaviceps as well as other rare, nocturnal and inconspicuous species. We confirmed for the first time the occurrence of the thin-spined porcupine Chaetomys subspinosus in the Park. Species richness varied across survey areas and forest types. Our findings demonstrate the potential of arboreal camera trapping to inform conservation strategies.

Application of long-term passive acoustic monitoring to evaluate spatial and temporal patterns of multi-species acoustic assemblages of marine mammals in the western North Atlantic Ocean

Passive acoustic monitoring (PAM) is an efficient method for large-scale marine mammal monitoring. PAM technologies concurrently sample multiple soniferous marine mammal species, and when coupled with verified detectors, provide information that can be used to evaluate community composition. This analysis used data collected by an array of high-frequency PAM recorders at eight sites between 30°0’N and 42°0’N along the shelf-break in the western North Atlantic Ocean. Daily acoustic presence of 13 known marine mammal species and grouped unknown odontocetes was determined for all months between June 2016 and May 2019. Classification trees were generated from monthly summaries of daily detections to identify community composition dissimilarities. Detections of Gervais’s beaked whale (Mesoplodon europaeus) represented the root node and split sites by latitude, grouping the three sites south of 34°0’N and the five sites north of 38°0’N. Tree nodes were further divided by other odontocetes. The presence of mysticetes also varied by site and season. Distinctive communities were identified for each site, with odontocetes being resident and mysticetes more migratory. The root and secondary splits were all driven by beaked whale species, demonstrating the importance of identifying these whales to species instead of aggregating them as is common for visual survey data.

Late Pleistocene large-bodied mammalian fauna from Mocun cave in south China: Palaeontological, chronological and biogeographical implications

This paper reports the discovery of a new mammalian assemblage at Mocun cave in 2000 by the Natural History Museum of Guangxi. The Mocun site is located in a residual karst peak in southwest Guangxi, south China. Abundant mammalian fossil teeth and bones were extracted from relatively thick deposits, well constrained stratigraphically. The results show that 1) the Mocun fauna is composed of typical species of the “Ailuropoda-Stegodon association”, including Stegodon, Ailuropoda, Rhinoceros, Pongo, Tapirus, Megatapirus, and Elephas, common in the Middle to the Late Pleistocene, with a larger portion of modern species; 2) By employing U-series dating (MC-ICP-MS) method on both the soda straw stalactites and mammalian teeth collected from deposits, the age of the Mocun fauna has been constrained between 66 and 101 ka, a transitional period from the interglacial stage MIS5 to the beginning of the last glacial stage (MIS4), representing one of the securely dated Late Pleistocene sites in southern China so far; 3) The composition in large mammals suggests a forested environment which harboured a great biodiversity in large species; 4) The taphonomic analysis indicates that the fossil accumulation is mainly due to activities of porcupines and to water flows; 5) Interestingly, our taxonomic study reveals some changes in the occurrence of Tapirus sinensis and Megatapirus augustus between ∼66 and ∼86 Ka, along with a change in the abundance of artiodactyls versus primates. It remains to demonstrate with more comprehensive records if these changes may be related to the mid-Late Pleistocene climatic transition.

Agri-driven habitat modification and small mammal species assemblage nexus in the Atewa Range and Bimpong Forest Reserves, Ghana

This study provides first-hand information on how the changing microhabitat in evergreen forests influences the assemblage of small terrestrial mammals. 30 plots of 100 × 50 metres were randomly sampled in the closed forest, open forest and farmlands habitats. Four transects, 100 m in length, spaced at 10 m, were established in each plot. Ten traps spaced at 10 m from each other were placed on each transect. In the dry and wet seasons, small mammals were captured for three consecutive nights twice a year using Sherman collapsible traps baited with oatmeal and groundnut paste. Small mammals were photographed and identified to species level in situ. The multidimensional scaling method was used to identify clusters of sites based on the composition of their communities. Differences in species composition among habitat types were tested using Permutational Multivariate Analysis of Variance. To identify the species contributions to the major differences between habitat types, a SIMPER analysis was performed. Species richness was compared by subjecting the relative abundance data to an individual-based rarefaction technique. Species diversity of the habitat types in the study areas was compared using the Renyi diversity ordering approach. A total of 507 individual small mammals of 22 species were sampled from both study sites. Our analysis revealed that the composition of small mammal species differed significantly between habitat types in the two study areas. Praomys tullbergi, Mastomys natalensis and Mus minutoides contributed 27.5%, 16.8% and 14.4%, respectively to overall community dissimilarity between the habitat types. Together these three species contributed to 54.8% and 62.8% of observed dissimilarities in Atewa and Bimpong study areas respectively. Overall observed species richness in Atewa (16 species) was higher than Bimpong (14 species). Generally, farmlands and open forests were more abundant, species-rich and diverse than the closed forest habitats in both study areas. Our results supported the hypothesis that different habitat types (farmlands, open forest, and closed forest) in the study areas will differ in small mammal assemblage due to different levels of disturbances.

Multiple dimensions of biodiversity in paleotropical hotspots reveal comparable bat diversity

AbstractBat species commonly comprise at least 50% of tropical mammalian assemblages, but Afrotropical bat faunas have been little studied leading to perceptions that they are depauperate. Here, we compare alpha taxonomic, functional, and phylogenetic diversity of insectivorous bats belonging to the narrow‐space foraging ensemble from a bat diversity hotspot in Nigeria to species‐rich sites in Indonesia and Malaysia, using previously published data. The Nigerian site is protected unlogged forests at Afi Mountain Wildlife Sanctuary and Cross River National Park. For comparison, we targeted similar unlogged forest sites in Southeast Asia: Indonesia—Bukit Barisan Selatan National Park Forest in Sumatra; and Kakenauwe Forest Reserve on Buton Island, Sulawesi; and another in Malaysia—Krau Wildlife Reserve. All sites were sampled using comparable methods, with an emphasis on harp traps that effectively capture the forest‐interior ensembles. We also compare regional beta diversity of bat assemblages in ecoregions using occurrence data (literature, unpublished records, and online natural history collections) from the Lower Guinean Forest and the Malay Peninsula. We demonstrate comparable alpha taxonomic, functional, and phylogenetic diversity of narrow‐space bats among sites in Nigeria and Indonesia, but greater diversity in Malaysia. Turnover and overall beta diversity of bats among ecoregions was comparable between the Lower Guinean Forest and the Malay Peninsula, but nestedness was higher in the latter. Our results reiterate the value of harp traps in generating bat survey data that allows equatable comparisons of “mist net avoiders” in the Paleotropical forest understory. Our findings have implications for regional and local bat conservation.