Mammal Assemblages Research Articles

Can NDVI identify drought refugia for mammals and birds in mesic landscapes?

Refugia within landscapes are increasingly important as climate change intensifies, yet identifying refugia, and how they respond to climatic perturbations remains understudied. We use Normalized Difference Vegetation Index (NDVI) developed during extreme drought to identify drought refugia. We then utilise camera trapping to understand the ecological role and importance of these refugia under fluctuating rainfall conditions. Ground foraging mammals and birds were surveyed annually from 2016 to 2019 whereby 171 remote-sensing cameras were deployed in the southern section of the Grampians, Australia. NDVI values were calculated during Australia's millennium drought, allowing the assessment of how NDVI calculated during extreme drought predicts drought refugia and the response of biodiversity to NDVI under rainfall fluctuations. Site occupancy of bird and mammal assemblages were dependent on NDVI, with areas of high NDVI during drought exhibiting characteristics consistent with refugia. Rainfall pulses increased site occupancy at all sites with colonisation probability initially associated with higher NDVI sites. Extinction probabilities were greatest at low NDVI sites when rainfall declined. Within mesic systems, remotely sensed NDVI can identify areas of the landscape that act as drought refugia enabling landscape management to prioritise species conservation within these areas. The protection and persistence of refugia is crucial in ensuring landscapes and their species communities therein are resilient to a range of climate change scenarios.

New fossil mammalian assemblages and first record of ostrich from the Pinjore (Pinjor) formation (2.58–0.63 Ma) of Siwalik Hills near Chandigarh, northern India

The Pinjore Formation of the Upper Siwalik subgroup, north of Chandigarh, provides one of the most extensive and continuous sequences of Quaternary deposits in northern India. Since the early 19th century, scholars have been involved with extensive surveys and comprehensive fossil collections from the region. However, most fossils were collected as surface finds. New palaeontological surveys were initiated in 2020 to identify in-situ fossil scatters to understand palaeoecological and palaeodietary shifts in fauna within the Pinjore deposits (2.58–0.63 Ma). As a result, six new palaeontological localities were discovered in the region, with 981 fossil specimens (dental, post-cranial and fossil eggshells). The post-cranial remains are fragmentary and undiagnosable, but dental remains can be identified to eight mammalian species of bovids, equids, proboscideans and rodents. More significantly, fossilised ratite eggshells were also discovered and collected from four separate scatters across the locality of Choti Badi Nangal and can be provisionally assigned to Struthio cf. S. camelus molybdophanes. This is also the first report of fossilised ratite eggshells from the Upper Siwalik Hills of India.

New data from the first discovered paleoparadoxiid (Desmostylia) specimen shed light into the morphological variation of the genus Neoparadoxia

Desmostylia is an extinct clade of marine mammals with two major sub-clades, Desmostylidae and Paleoparadoxiidae, known from Oligocene to Miocene strata of the North Pacific coastline. Within Paleoparadoxiidae, three genera have been identified: Archaeoparadoxia, Paleoparadoxia, and Neoparadoxia. The latter taxon is the geochronologically youngest palaeoparadoxiid and Neoparadoxia is characterized by a comparatively larger body size, although it is known only from a few specimens within a short temporal and geographic range. Here we report the discovery of an isolated tooth, which we identify as Neoparadoxia cf. N. cecilialina, constituting only the second individual specimen of Neoparadoxia with preserved dentition yet reported. This specimen was collected near Corona, California, USA, and we attribute it to the “Topanga” Formation, extending the geographic range of this taxon in Southern California. While the exact geographic locality was not recorded when it was collected in 1913, we establish two potential localities based on associated hand-written museum label and new stratigraphic information. Although initially identified as Desmostylus hesperus, this specimen of Neoparadoxia was collected 10 years before the first named paleoparadoxiid from Japan. We expect that description of more complete desmostylian material from elsewhere in Southern California will clarify the taxonomic richness and paleoecological role of this clade in Cenozoic marine mammal assemblages.

Late Quaternary (MIS 5a-5b) climate and environments of western Iberia inferred from the small-mammal assemblage of Gruta da Oliveira, Torres Novas, Portugal

Marine Isotope Stage 5 (MIS 5) is well represented in palynological studies of North Atlantic marine cores but in only a handful of archeological sequences from the adjacent Iberian landmass. In this paper, we undertake a multi-proxy analysis of small mammal assemblages (insectivores, bats, and rodents) from a 6 m-thick succession, dated to MIS 5a-5b (Layers 7–22), situated in the southeastern edge of the Central Limestone massif of Estremadura at Gruta da Oliveira, near Torres Novas, Portugal. Application of quantitative (Habitat Weighting, Simpson's Diversity Index) and qualitative (Mutual Ecogeographic Range, Bioclimatic Model, Quantified Ecology) methods suggest that open woodland habitats were dominant through the time of accumulation with reconstructed mean annual temperatures (MAT) tracking the 18O curve from the NorthGRIP ice core, from the end of MIS 5c to the beginning of MIS 4. Our findings are consistent with the general trends derived from other Gruta da Oliveira proxies (wood charcoal, coprolite pollen, large mammal associations), limited evidence from other MIS 5 terrestrial sites in Iberia, and offshore marine palynological records.

Broad scale functional connectivity for Asian elephants in the Nepal-India transboundary region

The Nepal-India transboundary region hosts one of Asia's most complex large mammal assemblages, including a small (but growing) population of Asian elephants (Elephas maximus). These elephants occur in four widespread and geographically disjunct subpopulations, and some of them undergo seasonal transboundary movements. We conducted a broad-scale evaluation of the amount and quality of elephant habitat available in the region and of functional landscape connectivity between and within subpopulations using Maxent, circuit theory, and least-cost path analysis. Habitat suitability was highly influenced by abiotic geographical factors (altitude and precipitation) and less by ecological factors (habitat heterogeneity, plant productivity) and human disturbance (distance to settlements). The region had a relatively small amount of high and optimal suitability habitat (12.6% out of 93,700 km2) but all subpopulations seem to be far from carrying capacity, suggesting ample potential for further population growth. Landscape connectivity was higher between and within the west and far-west subpopulations, which should be considered a single subpopulation. The central and ea st subpopulations, however, had low to very low between-subpopulation connectivity. Conservation priorities include maintaining the current connectivity in the west subpopulation and across the border in the east, and protecting high-quality habitats in eastern Nepal. Restoring connectivity between the central and other subpopulations is possible if the number of elephants continues growing, and it should be a long-term conservation aspiration. Maintaining and enhancing landscape connectivity in this region requires transboundary cooperation and coordination between Nepali and Indian authorities. If successful, it will bring considerable benefits for the conservation of elephants and other wildlife.

Relative efficiency of two models of snap traps for sampling boreal small mammals

AbstractSnap traps have long been a cost‐effective means of monitoring small mammal (<60 g) diversity and abundance, particularly at larger spatial or temporal scales. Yet, studies on the relative efficiency of snap trap models are surprisingly rare in the literature. We assessed the relative efficacy of Victor Mouse and Woodstream Museum Special snap traps for sampling boreal small mammals. Paired traps were set for 2–3 nights at 40–50 trapping stations at each of 110 sites, for a total sampling effort of 28,910 trap nights. We captured 1,013 small mammals representing 13 species. Overall, Museum Special traps caught almost twice as many small mammals as Victor traps. There was no difference in the sex or age‐class of the overall capture in the 2 trap models. However, Museum Special traps were triggered without capturing a small mammal 31% more often than Victor traps. Results for the six most frequently captured species (Myodes rutilus, Microtus pennsylvanicus, Microtus oeconomus, Microtus xanthognathus, Peromyscus maniculatus, and Sorex cinereus) mirrored those for overall captures. Moreover, the percent of the total capture in Museum Special traps ranged between 57–80% for each of the above species, indicating species‐specific responses to trap type. Our data further demonstrate the superior ability of Museum Special traps to capture boreal small mammals compared to Victor traps, which is likely attributed to a more sensitive trigging mechanism. Implications of our results suggest caution when mixing trap models in monitoring programs, or when interpreting results obtained with different trap models. We encourage similar comparisons in different biomes with different small mammal assemblages as trap performance is likely species specific.

New Discovery of Hipparion theobaldi Skull from the Late Miocene of Padhri, District Jhelum, Punjab, Pakistan and Associated Mammalian Fossil Assemblage

AbstractA fossil‐bearing locality near Padhri village, Dhok Pathan, 55 km away from the tehsil Dina, Jhelum District, in the Potwar Plateau, Middle Siwaliks, Punjab, northern Pakistan, is significantly rich in mammalian fossils. This site has provided an abundant mammalian fossil fauna of Late Miocene age from the Dhok Pathan Formation (Fm.). The recovered material belongs to four families: Equidae (horses), Rhinocerotidae (rhinos), Bovidae (cows), and Suidae (pigs). We discovered a new skull of hipparionine Hipparion theobaldi from this locality along with 22 specimens from the associated assemblage of fossil mammals. The recovered material includes seven other species: the aceratheriine Chilotherium intermedium, boselaphines Tragoportax punjabicus, Selenoportax vexillarius, Pachyportax latidens, the antelope Gazella lydekkeri and suinine Propotamochoerus hysudricus. The specimens are isolated teeth, fragments of maxilla, mandibles and horn cores. The Dhok Pathan Fm. is generally composed of claystone, siltstone and sandstone beds and, based on the mammalian fauna, the Padhri fossil locality is dated as Late Miocene. Thi99s formation was deposited in a subtropical paleoenvironment and the predominance of fossil bovids indicates extremely moist conditions with small but frequent standing water bodies.

Disappearance of an ecosystem engineer, the white-lipped peccary (Tayassu pecari), leads to density compensation and ecological release

Given the rate of biodiversity loss, there is an urgent need to understand community-level responses to extirpation events, with two prevailing hypotheses. On one hand, the loss of an apex predator leads to an increase in primary prey species, triggering a trophic cascade of other changes within the community, while density compensation and ecological release can occur because of reduced competition for resources and absence of direct aggression. White-lipped peccary (Tayassu pecari—WLP), a species that typically co-occurs with collared peccary (Pecari tajacu), undergo major population crashes—often taking 20 to 30-years for populations to recover. Using a temporally replicated camera trapping dataset, in both a pre- and post- WLP crash, we explore how WLP disappearance alters the structure of a Neotropical vertebrate community with findings indicative of density compensation. White-lipped peccary were the most frequently detected terrestrial mammal in the 2006–2007 pre-population crash period but were undetected during the 2019 post-crash survey. Panthera onca (jaguar) camera trap encounter rates declined by 63% following the WLP crash, while collared peccary, puma (Puma concolor), red-brocket deer (Mazama americana) and short-eared dog (Atelocynus microtis) all displayed greater encounter rates (490%, 150%, 280%, and 500% respectively), and increased in rank-abundance. Absence of WLP was correlated with ecological release changes in habitat-use for six species, with the greatest increase in use in the preferred floodplain habitat of the WLP. Surprisingly, community-weighted mean trait distributions (body size, feeding guild and nocturnality) did not change, suggesting functional redundancy in diverse tropical mammal assemblages.

Radiocarbon dates and late Quaternary vertebrates from cave deposits in the central Canadian Rocky Mountains

New radiocarbon dates on biological remains from cave deposits in the Canadian Rocky Mountains range in age from infinite to modern but are largely restricted to the Holocene (9560±40 years B.P. to modern). The consistency in radiocarbon ages is interpreted as resulting from geologic processes associated with deglaciation and may reflect timeframes when cave conditions in some areas of the Canadian Rocky Mountains became suitable for deposition and preservation of biological remains. When considered at taxonomic levels permitted by morphological identification, recovered vertebrate remains from cave deposits are consistent with the modern biota of the region, suggesting early post-Late Glacial Maximum establishment of the modern biota and relative stability of mammal assemblages through the Holocene. Preliminary evaluation of recovered plant remains highlights a potentially underevaluated source of palaeoecological data for higher elevations.

Road Permeability Index as a tool for mitigation planning of road impacts on wildlife in Colombia: a case study using mammals

Mitigation planning for road projects in Colombia has been largely based on actions aimed at reducing wildlife roadkills. Nonetheless, the efficiency of these actions is compromised because of the absence of robust empirical studies supporting their implementation. In this work, I used the Road Permeability Index (RPI) in conjunction with expert knowledge information to estimate the strength of the barrier effect imposed by an under-construction road (Yuma road, Santander department, Colombia) on nine functional groups of medium and large-sized mammals. The influence of 12 landscape variables on the permeability of each functional group was assessed at 30 locations along the road. The RPI was calculated for each functional group, and the whole studied mammal assemblage at each location. The relative influence of each variable on overall permeability was also estimated. I found that functional groups including terrestrial and semiarboreal species present higher contribution values to overall road permeability, indicating that they represent priority targets for mitigation actions. The RPI identified six highly permeable locations for animal movement—where higher roadkill rates are expected—which are key for implementing mitigation strategies aimed at reducing wildlife road mortality. Forest cover had the strongest influence on road permeability, therefore is crucial for landscape conectivity. Overall, the results of this work show that RPI constitutes a reliable and easily adaptable alternative for identifying priority species, or faunal groups, and locations for road mitigation planning.

Late quaternary biotic homogenization of North American mammalian faunas

Biotic homogenization—increasing similarity of species composition among ecological communities—has been linked to anthropogenic processes operating over the last century. Fossil evidence, however, suggests that humans have had impacts on ecosystems for millennia. We quantify biotic homogenization of North American mammalian assemblages during the late Pleistocene through Holocene (~30,000 ybp to recent), a timespan encompassing increased evidence of humans on the landscape (~20,000–14,000 ybp). From ~10,000 ybp to recent, assemblages became significantly more homogenous (>100% increase in Jaccard similarity), a pattern that cannot be explained by changes in fossil record sampling. Homogenization was most pronounced among mammals larger than 1 kg and occurred in two phases. The first followed the megafaunal extinction at ~10,000 ybp. The second, more rapid phase began during human population growth and early agricultural intensification (~2,000–1,000 ybp). We show that North American ecosystems were homogenizing for millennia, extending human impacts back ~10,000 years.

Camera trapping arboreal mammals in Argentina’s Atlantic Forest

Abstract Canopy camera trapping is being increasingly used to characterize assemblages of arboreal mammals. In this study we compared, for the first time, the assemblage of arboreal mammals of the Atlantic Forest, surveyed using canopy camera trapping at two protected areas of Misiones, Argentina: Piñalito (11 camera-trap stations) and Cruce Caballero (9 stations), with the assemblage recorded at ground-level with a camera-trapping survey conducted at another protected area, the nearby private reserve Valle del Alegría (18 stations). We calculated the number of independent photo-events for each species and site, and we built species rank abundance curves to compare the recorded species diversity among sites. We recorded six mammal species at Piñalito and Cruce Caballero, and 23 at Valle del Alegría. Canopy-survey sites showed lower diversity but a different and non-nested species composition when compared to the ground-level survey. One of the most frequently recorded species in the canopy, the brown-eared woolly opossum, Caluromys lanatus, categorized as Vulnerable in Argentina, has not been photographed in ground-level camera-trap surveys in Misiones before. Our results suggest that canopy camera trapping represents a robust method to sample arboreal species that are missed in ground-level camera-trap surveys, thus improving forest species inventories.

Andean non-volant small mammals: A dataset of community assemblages of non-volant small mammals from the high Andes.

Information from diversity inventories was used to study patterns of biodiversity and species distribution, to identify potential priority areas for conservation, and to guide future sampling efforts. In this context, we compiled information on non-volant small mammal communities from the high Andes (>2000 m). Here, we present an open source dataset containing information on diversity (species composition, number of individuals captured), inventory design (type of traps, sampling efforts), and environment (habitat) for both unpublished and published information. This study covers 630 mammalian communities, geographically distributed throughout the Andes in Venezuela, Colombia, Ecuador, Peru, Bolivia, Argentina, and Chile. We compiled a total of 26,412 individual records belonging to 240 species; the order with greatest number of records was Rodentia (n=25,319, 96.06%), followed by Didelphimorphia (n=373, 1.42%), Eulipotyphla (n=358, 1.36%) and Paucituberculata, (n=307, 1.16%). Andean non-volant small mammal communities harbor a range from 1 to 17 species, with 93.06% of sites being composed of one to five species, 27.78% of sites with species richness varying from 6 to 10 species, and 4.17% sites composed of more than 10 species. Multiple sampling methods were used to survey non-volant small mammals; the most representative methods were snap-traps and Sherman traps, or a combination of both, in more than 81% of the studies. This data paper represents the first large dataset of faunal species inventories for the Andes. There are no copyright restrictions associated with the use of this dataset. Please cite this data paper when its data are used total or partially in research or teaching.

Continental-scale local extinctions in mammal assemblages are synergistically induced by habitat loss and hunting pressure

Understanding local-scale patterns of vertebrate species persistence or extirpation in the Anthropocene is a central challenge in conservation ecology. Based on real-world occurrences of 83 mammal ecospecies (i.e. strict ecological analogues often represented by parapatric congeners) across 1029 surveyed sites within the entire Neotropical realm, we set out to identify and disentangle the role of life-history traits under a phylogenetically controlled design in explaining local extinctions given the two leading threats to these species, namely habitat loss (the inverse of remaining habitat area [i.e. 100 – habitat area]) and hunting represented by a metric that ranged from −1.0 (non-hunted sites) to +1.0 (heavily hunted sites). We also examine the dominant role of body size in either reducing or aggravating local extinctions. We analyzed this large dataset using descriptive statistics, Generalized Linear Mixed Models, Phylogenetic Generalized Least Squares, and Phylogenetic Generalized Linear Mixed Models. Habitat loss was the leading driver of local extinctions affecting 75 % of all mammal species, whereas hunting exerted a coup de grâce effect on 70 % of the species whose local fates were determined by the synergistic interaction between habitat loss and hunting. Our results show that Neotropical sites across landscapes retaining ≤30 % of their original habitat and subjected to heavy levels of hunting pressure (≥0.40) contained only ~35 % of the historical mammal fauna. Even after the millennial timescale that shaped modern biotas, threats to the Neotropical megafauna have never been as severe as in the last five decades. Given the narrowing time window for mitigation action, it becomes imperative to implement conservation plans to effectively prevent or inhibit these leading threats to this vertebrate fauna.

Altitudinal dispersal process drives community assembly of montane small mammals

Montane small mammals are subjected to strong forces of dispersal limitation and habitat filtering that mainly operate on their community structures along the altitudinal direction. However, so far little is known about the relative contributions of dispersal and niche processes to their community assembly. By applying the newly proposed PER‐SIMPER/DNCI (dispersal–niche continuum index) framework to small mammal occurrence data collected from 21 extensive altitudinal gradients, we quantitatively assessed the relative importance of dispersal and niche processes on mammalian community assembly in a large mountainous region of southwestern China. We compared the pairwise DNCI values among assemblages from low, middle and high altitudinal zones and overall DNCI values between glires and insectivores that differ in dispersal abilities to test three explicit (altitudinal connectivity, environmental difference and dispersal ability) hypotheses. The overall DNCI values for all small mammal species combined (−12.7 ± 0.4, 90 species), glires (−12.8 ± 0.5, 56 species) and insectivores (−13.5 ± 1.4, 34 species) values were all negative, while insectivores showed a lower value than glires. For both all species combined and glires, we found a lower pairwise DNCI value between the low and high altitudinal zones than that between the other two pairs of altitudinal zones. Our study indicated that an altitudinal dispersal process dominates the taxonomic composition of small mammal assemblages in this region. Importantly, the results reinforced the idea that community structures of less vagile taxa are more subject to dispersal limitation; and yet another idea that assemblages from further altitudinal areas are more differentiated by dispersal process was only supported in glires and all species combined. Community biologists should, therefore, pay attention to recent climate‐induced upward range shifts by montane species, which may dramatically alter their community structures in different altitudinal zones through dynamics of immigration and mountaintop extinction.

Small Animals, Big Impact? Early Farmers and Pre- and Post-Harvest Pests from the Middle Neolithic Site of Les Bagnoles in the South-East of France (L'Isle-sur-la-Sorgue, Vaucluse, Provence-Alpes-Côte-d'Azur).

Simple SummaryArchaeological excavations at Les Bagnoles (SE France) unearthed three Middle Neolithic water wells (4250–3700 cal B.C.) whose waterlogged conditions allowed the preservation of organic remains, notably a large number of rodent and beetle species. The evaluation of these results in the context of an open-air farming site raised the question of whether these species could have posed a threat to both the field plants and crops stored at the Middle Neolithic settlement. The findings of this study suggest that the native wood mouse was probably one of the first unwanted inhabitants of human settlements in Europe prior to the appearance of the invasive house mouse during the Bronze Age. The analysis also advances the argument that the storage pest grain weevil played a role in the clear shift in the crop spectrum from naked to glume wheat around 4000 B.C., as glume wheats are less vulnerable to its infestation. Moreover, the current study demonstrates that investigating insects and rodents from archaeological sites is key to grasping the challenges of the competitive relationship between Neolithic farming communities and pests.Pests appear to have accompanied humans and their crops since the beginning of farming. Nevertheless, their study is only rarely integrated into research on farming in prehistory. An assemblage of invertebrates and small mammals was recovered from the waterlogged layers of three wells at the Middle Neolithic site (4250–3700 cal B.C.) of Les Bagnoles (SE France). The microfaunal remains were retrieved from sediment samples by wet sieving (wash-over technique). The most common among the rodents is the wood mouse. The assemblage also consists of insect remains of grain weevil, seed beetle, and corn ground beetle. The different finds not only offer data on the role of insect and rodent pests in the Neolithic but on the possible strategies adopted by the early farming communities in the western Mediterranean in response to pest infestation. The findings appear to confirm the hypothesis that the wood mouse was a commensal and storage pest in settlements long before the arrival of the invasive house mouse during the Bronze Age. The presence of the main storage pest, the grain weevil, suggests a long-term grain storage issue at Les Bagnoles. The combination of the results of the site’s archaeobotanical findings with those of other sites in the western Mediterranean suggests that the shift from naked to glume wheat around 4000 B.C. may also stem from a reaction to the problem of grain weevil infestation.

Beydere 3: a new early Miocene small mammal assemblage from the western Anatolia, Turkey

ABSTRACT The new micromammal site of Beydere 3 represents a typical Anatolian MN3 fauna in the high diversification and abundance of Eumyarion. Notably, two Eumyarion species are new; combined, they make up almost half of the assemblage. While Eumyarion beyderensis sp. nov. shows simple morphology in upper molars, Eumyarion aegeaniensis sp. nov. shows a more complex lophs pattern. In addition, Beydere 3 yielded nine species of rodents and an ochotonid: the hamsters Cricetodon kasapligili, Mirrabella crenulata, Megacricetodon hellenicus, Democricetodon doukasi, Vallaris zappai and Eumyarion sp., the dormice Glirulus ekremi and Glis sp., the beaver Steneofiber eseri, the squirrel Palaeosciurus fissurae and Ochotonidae indet. The fauna is significant in that it represents the first common occurrence of Megacricetodon in Anatolia. Eumyarion and Megacricetodon are both dominant groups which may indicate a signal of environmental change, but still closer to wet conditions. This, in combination with the new species of Eumyarion, suggests that Beydere 3 represents a time slice which was previously not recorded in Anatolia. Radiometric dating of ashes overlying the section indicates that the age of the locality is older than 18.21 (± 0.19) Ma.

Microhabitat, altitude and seasonal influence on the abundance of non-volant small mammals in Mount Rungwe forest nature reserve

A study on microhabitat, altitudinal and seasonal influences on small mammal abundance in Mount Rungwe Nature Forest Reserve, Tanzania was carried out from March 2019 to February 2020 during the wet and dry seasons. Live traps were used in six grids and six transect lines for capturing small mammals at the low, mid, and high elevations (1700–2600 m.a.s.l.). Generalized linear models were used to examine the effects of microhabitat characteristics, altitude, and seasons on the relative abundance of small mammals. A total of 444 rodents and shrews were recorded on 4320 trap nights. Rodent species recorded included Beamys hindei, Cricetomys ansorgei, Dendromus insignis, Grammomys ibeanus, Graphiurus murinus, Lophuromys machangui, Praomys delectorum, and one shrew, Crocidura sp . Overall, P. delectorum was the most dominant species in all elevations, with 68.9% of all captures. Mid elevation had a higher abundance of small mammals (Estimate ± SE = 1.17 ± 0.49, Z = 2.37, p = 0.0176). Species abundance was influenced differently by elevation. While P. delectorum decreases with increasing elevation, L. machangui increases with an increase in elevation. Although overall small mammal abundance was not affected by microhabitat variables (Estimate ± SE = −0.08 ± 0.13, Z = −0.67, p = 0.5050), individual species ( P. delectorum and L. machangui ; Estimate ± SE = 0.13 ± 0.06, Z = 1.95, p = 0.05 and −0.31 ± 0.09, Z = 3.34, p = 0.0008 respectively) were affected differently. While P. delectorum abundance showed a positive correlation and increased with an increase in PCA1 in GLM, L. machangui had a negative trend that shows they were affected differently. Small mammal abundance, on the other hand, was affected by season and, in particular, rain, with low abundance during heavy rains and dry cold periods (Estimate ± SE = 0.51 ± 0.14, Z = 3.6, p = 0.0003 and 0.3 ± 0.15, Z = 2.08 p = 0.04 respectively). In general, the results show that microhabitat parameters, elevation, and season influenced small mammals’ abundance in MRFNR. This outcome indicates that altering the microhabitat could have an impact on the small mammal assemblage and particularly their abundance. Thus, microhabitat, elevation, and season influence small mammal abundance and can be used as a proxy for evaluating the biodiversity of montane tropical small mammal communities.

Stepping-stones and Mediators of Pandemic Expansion—A Context for Humans as Ecological Super-spreaders

Humans represent ecological super-spreaders in the dissemination and introduction of pathogens. These processes, consistent with the dynamics of the Stockholm paradigm, are exemplified in the origin and globalized distributions of SARS-CoV-2 since initial recognition in central Asia during 2019 and 2020. SARS-like viruses are not widespread in mammals but appear widespread in chiropterans. Bats are isolated ecologically from most other assemblages of mammals in terrestrial systems. Humans may be the stepping-stone hosts for broad global dissemination and wider infection (given the opportunity) among diverse assemblages of mammals in which host and viral capacity are compatible. Human globalization mediated insertion in global ecosystems along primary and secondary pathways initially with localized to regional circulation across continents. Origins and persistence of cycles involving variants and viral transmission among other mammals and the potential for secondary exposure (retrocolonization) of people occurs on multidirectional pathways. Humans were responsible for the initial breakdown in ecological isolation of the virus that facilitated colonization events from chiropterans to other mammals. In the absence of these human drivers, environmental or ecological interfaces (boundary zones among habitats) limiting the distribution of SARS-CoV-2 are unlikely to have been crossed, leaving a diverse assemblage of SARS-like viruses (Sarbecovirus) remaining relatively hidden and isolated in southeast Asia.

Difference in small mammal assemblages in the diet of the Common Barn-Owl Tyto alba between two landscapes

As an opportunistic predator, the Common Barn-owl (Tyto alba) proved to be an appropriate model organism to survey the composition of small mammal assemblages. This study analysed barn owls’ pellet samples from 14 localities containing 34 animal taxa and 4,088 prey items in two years (2015–2016). Two groups of samples (7–7 localities) were separated based on the dominance of semi-natural habitats and agricultural lands. Rarefaction analysis proved that the species richness and diversity of barn owls’ diet were significantly higher in semi-natural landscapes. The multiple regression analysis between PCA scores showed that in the agrarian landscape the abundance of generalist species was influenced by the proportion of forests, while the value of the trophic level index was determined by the size of arable fields. In the case of semi-natural landscapes, the abundance of the synantrop guild and generalist species, especially S. araneus and A. agrarius, was influenced by the proportion of urban areas, the number of habitats and the size of arable fields. The results of this study suggested that the small mammal consumption of the Common Barn-owl is significantly different in the two landscapes, which reflects the impact of habitat heterogeneity and agricultural activity on prey availability.