Mammal Species Richness Research Articles

Area of Habitat maps for the world’s terrestrial birds and mammals

Area of Habitat (AOH) is “the habitat available to a species, that is, habitat within its range”. It complements a geographic range map for a species by showing potential occupancy and reducing commission errors. AOH maps are produced by subtracting areas considered unsuitable for the species from their range map, using information on each species’ associations with habitat and elevation. We present AOH maps for 5,481 terrestrial mammal and 10,651 terrestrial bird species (including 1,816 migratory bird species for which we present separate maps for the resident, breeding and non-breeding areas). Our maps have a resolution of 100 m. On average, AOH covered 66 ± 28% of the range maps for mammals and 64 ± 27% for birds. The AOH maps were validated independently, following a novel two-step methodology: a modelling approach to identify outliers and a species-level approach based on point localities. We used AOH maps to produce global maps of the species richness of mammals, birds, globally threatened mammals and globally threatened birds.

Species richness and abundance of small mammals from Nimba region, Northeastern Liberia

This study was carried out in a biodiversity hotspot within the Nimba region located in the northeastern part of Liberia. The Nimba region is known to harbor exceptional fauna diversity. However, the small mammal communities in Nimba region are poorly documented. The aim of this study was to determine the species richness and relative abundance of rodents and shrews in five sites: Bento, East Nimba, Gangra-Yuelliton, Tokadeh and Vayampah. A total of 244 individual of small mammals comprising 18 species were trapped on 4,375 trap nights. Rodent species recorded include: Arvicanthis rufinus, Dephomys defua, Grammomys buntingi, Graphiurus lorraineus, Hybomys planifrons, Hybomys trivirgatus, Hylomyscus simus, Lemniscomys striatus, Lophuromys sikapusi, Malacomys edwardsi, Mastomys erythroleucus, Mus muscoloides, Mus setulosus and Praomys rostratus. Shrew species were Crocidura eburnea, Crocidura jouvenetae, Crocidura muricauda and Crocidura obscurior. The most dominant species was Hylomyscus simus (22.95%), followed by Praomys rostratus, Crocidura muricauda and Crocidura eburnea. The highest species richness was recorded at Gangra-Yuelliton and lowest at Tokadeh. Diversity indexes were higher at East nimba (H’ = 2.01; 1-D = 0.82) and Gangra-Yuelliton (H’ = 2.00; 1-D = 0.83) and lower at Tokadeh (H’ = 1.57; 1-D = 0.75). Similarity index revealed high resemblance in species composition between Bento and Vayampah. The lowest similarity was observed between Tokadeh and Gangra-Yuelliton. This study highlighted the high biological diversity of small mammal communities in Liberia's Mount Nimba region. Thus, this zoological group should now be taken into account in the biodiversity conservation strategies of Mount Nimba

Diversity and Relative Abundance of Ungulates and Other Medium and Large Mammals in Flooded Forests in the Dahomey Gap (Togo).

"The Dahomey Gap" is a human-derived mostly savannah region that separates the Guineo-Congolian rainforest block into two major units: the Upper Guinean and the Lower Guinean Forest blocks. Several forest patches are distributed throughout this savannah-dominated habitat. The mammal communities in the Dahomey Gap region have been poorly studied. In this paper we analyse the species richness and abundance of, as well as conservation implications for, medium and large mammals (especially ungulates) inhabiting a complex of flooded forests near the Mono river in south-eastern Togo. We use several field methods to describe the species richness of mammals in this area, including camera-trapping, recce transects, Kilometric Index of Abundance (KIA) estimates, examination of hunters' catches and face-to-face hunter interviews. Overall, we directly recorded 19 species that coexist in these forests. Based on interviews, nine other species were confirmed as present in the study area. Only five species were common: Cephalophus rufilatus, Tragelaphus scriptus, Chlorocebus aethiops, Atilax paludinosus and Herpestes ichneumon. The area still contains various threatened species such as Tragelaphus spekii and Hippopotamus amphibius. We stress that to ensure the protection of the Dahomey Gap mammals, it is important to seriously consider protecting not only the forest patches but also the surroundings, mainly savannah landscapes.

The loss of vegetation cover has distinct but short-term impact on multiple vertebrate taxa in a grassland ecosystem

Vegetation cover in grasslands typically fluctuates over time, for example, declining with grazing and disappearing entirely with burning. This temporal change in vegetation cover may impact the composition of vertebrate communities by altering habitats or perceived predation pressure. We manipulated vegetation cover in a high-elevation (ca. 1240–1500 m above sea level) grassland ecosystem and measured its effect on the community structure of birds and small mammals using a Before-After-Control-Impact study design. We established 12 plots (each plot 100 × 100 m) at Telperion Nature Reserve, Mpumalanga, South Africa, which were assigned to three treatments: mowed with cut grass left in situ (mowed-litter), mowed with cut grass cleared (mowed-cleared), and non-mowed (control). We sampled birds and small mammals over three sampling periods: before the treatment (August 2019), immediately after the treatment (October 2019), and three months after treatment (January 2020). We used point counts and Sherman live traps to surveys birds and small mammals, respectively. We observed a total of 2801 individuals of 38 species of birds and 98 individuals of eight species of small mammals. Species richness and diversity of small mammals and birds was significantly higher in the non-mowed plots compared with the mowed plots. Birds also showed differences in community composition in mowed and non-mowed treatments immediately after mowing but these differences disappeared three months after mowing, whereas small mammal composition did not differ before and after mowing. The best performing generalized additive model showed that vegetation biomass had a significant positive influence on bird species richness but not rodents. On the other hand, diversity of both taxa was significantly influenced by grass biomass. Our study suggests that loss of vegetation cover in grasslands has significant short-term effects on birds and small mammals, but that these faunal communities rapidly return to pre-loss conditions within a few months. Hence controlled vegetation removal (e.g. mowing) could be considered an appropriate tool for managing these high-elevation grasslands.

How the color of reflective materials influences the occurrence of mammals and birds

Color reflective materials have been widely employed in agriculture, airports, and road traffic as signals and to prevent the damage caused by mammals and birds. The negative impacts of such applications on wildlife have been acknowledged, but little is known about the particular effects of different colors applied to these materials. We recorded the occurrence of wildlife using 56 camera traps placed in locations affected by different reflective color sheeting (red, yellow, green, blue, white, mirror and control without disturbance) in a subtropical montane forest of southwestern China. We compared richness and abundance of ground bird and mammal species. The results showed that the yellow reflective material has an attractive effect on birds during daytime compared with the control group, while the red and green ones appear to repel them. However, the general tendency was a reduction of bird species occurring at night because of all the different sources of reflective light. For mammals, no significant difference was found among disturbances during either day or night. Species showed different responses to specific colors but further research in this regard is needed. Based on these experimental findings, we recommend that all reflective materials should be avoided or used carefully within protected areas. Moreover, red and green signals are suitable for airports and agriculture fields to effectively prevent damage and safety concerns inflicted by birds. Biodiversity, Conservation biology, Environmental contamination and remediation, Environmental impacts, Population biology

Footprint beds record Holocene decline in large mammal diversity on the Irish Sea coast of Britain.

Long-term monitoring along the Irish Sea coast of Britain at Formby has identified hundreds of animal and human footprints in 31 discrete sediment beds. A new programme of radiocarbon dating shows that the Formby footprints span at least 8,000 years of the Holocene Epoch from the Mesolithic period to Medieval times. In a landscape largely devoid of conventional archaeology and faunal records, we show how species data from the footprint stratigraphy document long-term change in both large mammal diversity and human behaviour. The footprint beds record shifting community structure in the native fauna through an era of profound global change. As sea levels rose rapidly in the Early Holocene, men, women and children formed part of rich Mesolithic intertidal ecosystems from ~9,000 to 6,000 cal BP, with aurochs, red deer, roe deer, wild boar, beaver, wolf and lynx. Doggerland was reclaimed by the sea in this period. In the agriculture-based societies that followed, after 5,500 cal BP human footprints dominate the Neolithic period and later beds, alongside a striking fall in large mammal species richness. Stacked footprint beds can form multimillennial records of ecosystem change with precise geographical context that cannot be retrieved from site-based fossil bone assemblages.

Small mammals in a mountain ecosystem: the effect of topographic, micrometeorological, and biological correlates on their community structure

An increasing number of studies have investigated spatial and temporal patterns in species richness and assemblage composition in mountain ecosystems along altitudinal gradients. Small mammals have been successfully used as indicators of environmental health and as proxies of biodiversity. However, information about the composition and distribution of species assemblages in the mosaic of habitat and rocky landform types at a high altitude is still lacking for most of the mountain regions. Through the use of live traps and camera trapping, we described the small mammal community living above the treeline of the Western Dolomites (Italian Alps), investigating the species richness, abundance of individuals and community composition in relation to topographic, micrometeorological, mesohabitat, and biological correlates. A total of five species and 50 individuals were sampled, analysed, and released. At the extremes of the analysed altitudinal range (i.e. 1900 vs 2900 m a.s.l.), community composition was completely different and species richness was related to elevation, steepness, and vegetation cover. At the same time, the taxonomic distinctness of ground-dwelling arthropods (namely carabid beetles and spiders), a proxy of habitat complexity, showed higher values in areas with a greater small mammal species richness. We found a positive effect of steepness and rocky landform type “carsism” on the number of captured individuals, showing the importance of the availability of shelters and underground burrows for the sampled species. As a confirmation of the altitudinal shift for these species in relation to the ongoing climate change, we detected a negative impact of sub-surface ground temperature on small mammal abundance during the monitoring period. In conclusion, small mammals represent an excellent model for understanding the evolutionary processes of ecosystems, population dynamics under changing environmental conditions, and habitat vulnerabilities.

Island size predicts mammal diversity in insular environments, except for land‐bridge islands

AbstractInsular environments are among the most endangered ecosystems as they face a myriad of anthropogenic stressors. Forest mammals perform a wide range of ecological services, with their persistence being vital for ecosystem functionality in both natural and artificial islands. Studies revealed that shrinkage in island size usually leads to the decay of mammal species richness and abundance in patchy landscapes. However, mammal species‐area (SARs) and abundance‐area (AARs) relationships can differ among insular environments: oceanic, fluvial, artificial, and land‐bridge islands (i.e., natural islands connected to the mainland). Large dams create vast insularized landscapes after river impoundment, leading to pervasive habitat loss and potentially causing even worse biodiversity losses than other insular systems. We conducted an extensive literature search and used meta‐analysis techniques to quantify the magnitude of SAR and AAR for forest mammals across different archipelago landscapes worldwide. After a screening process, we ended up with 26 studies comprising 55 different effect sizes representing the magnitude of SARs and AARs. Our global analysis unveiled a positive relationship between effect sizes and island area, with mammal species richness and abundance increasing in fluvial, oceanic, and artificial islands accordingly with island area, but not in land‐bridge islands. These results demonstrate that, except for land‐bridge islands, SAR and AAR are still fair models to predict mammal diversity. These results could improve the prediction of SAR and AAR in insular environments under habitat loss scenarios and propose sound conservation strategies since the rate at which insular communities have been lost is presently unknown.

Species richness, relative abundance and occupancy of ground-dwelling mammals denote the ineffectiveness of chimpanzee as flagship species

In conservation biology, flagship species are defined as species that can raise support for biodiversity conservation in a given place or social context. In the newly established Gishwati–Mukura National Park in Rwanda, the Eastern chimpanzee was considered such an ambassador. To test whether the flagship species concept was effective in the park, we studied species richness, relative abundance, and species distribution (occupancy) of medium- to large-sized, ground-dwelling mammals using camera trapping technology. The impact of three environmental and three anthropogenic variables on species distribution was investigated and the ecological diversity of the fauna in the national park assessed. Over a period of 9 months, two 4 × 4 camera trapping grids were deployed in Gishwati and Mukura Forest. Sampling effort in each forest equated to 32 and 29 camera trapping locations, yielding 258 and 242 independent photographic events of eight and six species, respectively. In both forests, the Emin's giant poached rat was the most frequently encountered species, while all other species showed high relative abundance only in Gishwati Forest. The relative abundance of the endangered Eastern chimpanzee in Gishwati Forest was 0.54, the estimated occupancy was 0.31. Single-species, single-season occupancy models revealed that forest cover, altitude and distance to forest edge influenced the detectability of L'Hoest's monkey and squirrel species, while no effect was found on their occupancy. Notably, no larger herbivore or carnivore species were observed in the park, while the flagship species, i.e., the Eastern chimpanzee, was relatively abundant. Moreover, in both forests, all detected carnivores were small- to medium-sized, suggesting a meso-predator release phenomenon, i.e., populations of medium-sized predators increased after the removal of larger, top carnivores, due to relaxed competition. It appears that the prioritization of the flagship species resulted in the neglect of other mammalian species, leading eventually into the demise of entire functional guilds. Based on these results, the Gishwati–Mukura NP was categorized as a ‘depleted forest’. We, therefore, strongly object chimpanzees as a suitable flagship species—at least in the Gishwati–Mukura NP—and recommend collating more knowledge on the release of meso-predators and the loss of forest ungulates to improve their future conservation in Afro-montane forest habitats.

Diversity, distribution and conservation of land mammals in Mauritania, North-West Africa

Detailed knowledge about biodiversity distribution is critical for monitoring the biological effects of global change processes. Biodiversity knowledge gaps hamper the monitoring of conservation trends and they are especially evident in the desert biome. Mauritania constitutes a remarkable example on how remoteness and regional insecurity affect current knowledge gaps. Mammals remain one of the least studied groups in this country, without a concerted species checklist, the mapping of regions concentrating mammal diversity, or a national assessment of their conservation status. This work assessed the diversity, distribution, and conservation of land mammals in Mauritania. A total of 6,718 published and original observations were assembled in a spatial database and used to update the occurrence status, distribution area, and conservation status. The updated taxonomic list comprises 107 species, including 93 extant, 12 Regionally Extinct, and 2 Extinct in the Wild. Mapping of species distributions allowed locating concentrations of extant mammal species richness in coastal areas, along the Senegal River valley, and in mountain plateaus. Recent regional extinction of large-sized Artiodactyla and Carnivora has been very high (11% extinct species). From the extant mammals, 11% are threatened, including flagship species (e.g., Addax nasomaculatus and Panthera pardus). Species richness is poorly represented by the current protected areas. Despite the strong advances made, 23% of species categorise as Data Deficient. Persisting systematics and distribution uncertainties require further research. Field surveys in currently unexplored areas (northern and south-eastern regions) are urgently needed to increase knowledge about threatened mammals. The long-term conservation of land mammals in Mauritania is embedded in a complex web of socioeconomic and environmental factors that call for collaborative action and investment in sustainable human development. The current work sets the baseline for the future development of detailed research studies and to address the general challenges faced by mammals and biodiversity in the country.

Predictors of Mammalian Diversity in the New York Metropolitan Area

Urbanization can have profound consequences for mammalian biodiversity and is thought to contribute to patterns of species richness and community composition. Large cities can be particularly challenging environments for mammals because these habitats are often impacted by anthropogenic perturbations, including high human population density, fragmented habitats, and extensive human development. In this study, we investigated mammalian species richness, Shannon–Wiener diversity, and evenness in the most densely populated region in the United States: the New York metropolitan area. Specifically, we deployed camera traps from 2015 to 2019 to investigate six drivers of mammalian diversity across 31 greenspaces: (1) human population density, (2) patch size, (3) habitat type, (4) surrounding land cover, (5) geographical barriers to dispersal, and (6) habitat heterogeneity. We found that mammal community composition is largely influenced by a multitude of anthropogenic factors. Specifically, mammal species richness was higher in greenspaces with larger patch sizes and lower in greenspaces surrounded by more development. Moreover, Shannon–Wiener diversity and evenness were higher in urban natural landscapes than human-altered landscapes. In a subset of data that only included carnivores, we found that carnivore Shannon–Wiener diversity was higher in urban natural habitats and in sites with lower human population densities. Finally, we found that geographical barriers to dispersal contributed to both patterns of mammalian diversity and patterns of carnivore diversity: mammal taxa richness, Shannon–Wiener diversity, and evenness were all significantly higher on the continent (Bronx/Westchester) than on Long Island. These results suggest that preserving urban greenspaces is important for maintaining both mammalian and carnivore biodiversity and that management of mammals in cities should concentrate on maintaining large, connected, natural greenspaces.

The counteracting effects of anthropogenic speciation and extinction on mammal species richness and phylogenetic diversity

AbstractAimHuman activities are causing massive increases in extinction rates but might also lead to drastic increases in speciation rates; for example, after human‐mediated spread of species to otherwise unreachable landmasses. The long‐term net anthropogenic effects on biodiversity therefore remain uncertain. Our aim was to assess the combined anthropogenic effects of extinctions and speciations on biodiversity over geological time‐scales.LocationGlobal.Time periodPresent and predicted future.Major taxa studiedTerrestrial mammals.MethodsWe estimated known anthropogenic and predicted future extinctions based on Red List categories from the International Union for Conservation of Nature. We inferred potential anthropogenic speciations, assuming that all introductions to isolated landmasses would, over time, evolve into distinct species. We then estimated changes in regional and global species richness and phylogenetic diversity attributable to these extinctions and speciations.ResultsWe demonstrated that if all species introduced onto new landmasses develop into new species, the number of anthropogenic speciation and extinctions eventually become similar. However, even after accounting for an anthropogenic increase in speciation, our estimates suggest recovery times for phylogenetic diversity of several millions of years.Main conclusionsOur results highlight that although humans are causing drastic biodiversity losses, human‐driven speciation could eventually counterbalance these losses in species numbers, whereas phylogenetic diversity, at least within our simulation scenarios, would remain permanently reduced. This conclusion, however, requires our pressures on biodiversity to cease soon and requires us to consider geological time‐scales rather than changes over this century.

The relative influence of history, climate, topography and vegetation structure on local animal richness varies among taxa and spatial grains.

Understanding the spatial scales at which environmental factors drive species richness patterns is a major challenge in ecology. Due to the trade-off between spatial grain and extent, studies tend to focus on a single spatial scale, and the effects of multiple environmental variables operating across spatial scales on the pattern of local species richness have rarely been investigated. Here, we related variation in local species richness of ground beetles, landbirds and small mammals to variation in vegetation structure and topography, regional climate, biome diversity and glaciation history for 27 sites across the USA at two different spatial grains. We studied the relative influence of broad-scale (landscape) environmental conditions using variables estimated at the site level (climate, productivity, biome diversity and glacial era ice cover) and fine-scale (local) environmental conditions using variables estimated at the plot level (topography and vegetation structure) to explain local species richness. We also examined whether plot-level factors scale up to drive continental scale richness patterns. We used Bayesian hierarchical models and quantified the amount of variance in observed richness that was explained by environmental factors at different spatial scales. For all three animal groups, our models explained much of the variation in local species richness (85%-89%), but site-level variables explained a greater proportion of richness variance than plot-level variables. Temperature was the most important site-level predictor for explaining variance in landbirds and ground beetles richness. Some aspects of vegetation structure were the main plot-level predictors of landbird richness. Environmental predictors generally had poor explanatory power for small mammal richness, while glacial era ice cover was the most important site-level predictor. Relationships between plot-level factors and richness varied greatly among geographical regions and spatial grains, and most relationships did not hold when predictors were scaled up to the continental scale. Our results suggest that the factors that determine richness may be highly dependent on spatial grain, geography, and animal group. We demonstrate that instead of artificially manipulating the resolution to study multiscale effects, a hierarchical approach that uses fine grain data at broad extents could help solve the issue of scale selection in environment-richness studies.

Fire exclusion and fire return interval affect small mammal populations in longleaf pine forests

Longleaf pine (Pinus palustris) forests are among the most fire-dependent forest types in the world and once dominated much of the southeastern United States. Loss and fragmentation of longleaf pine shrank its distribution to approximately 4% of its historic range; as a result, longleaf pine forests currently receive much conservation and restoration emphasis. In all cases, this emphasis includes prescribed fire. Prescribed fires promote herbaceous understories which maintains habitat for some small mammals, but fires can also result in temporary declines of small mammal populations. Therefore, short return intervals may not allow small mammal populations to recover between fires, and long return intervals may result in declining habitat quality and reduced small mammal abundance. During the first phase of our research, we studied the long-term influence of prescribed fire on small mammals. We annually estimated small mammal abundance and species richness during 2001 – 2014 in eight longleaf pine-dominated plots in southwestern Georgia, USA. Plots were either biennially burned (reference) or had fire excluded during the study. Small mammal species richness was similar in fire-excluded and reference sites. Overall small mammal abundance was greatest in reference plots. Five species were captured with sufficient frequency to justify species-specific analyses. Of these, three (hispid cotton rats, Sigmodon hispidus; oldfield mice, Peromyscus polionotis; and house mice, Mus musculus) were more abundant in reference plots. For the second phase of our research, we reintroduced fire in half of the fire excluded plots (burned during 2015, 2016, and 2017) and began sampling small mammals in three additional plots that were burned annually since 2003. We collected data during 2017 and 2018 for this phase of the research to evaluate small mammal response to four prescribed-fire return intervals (annual growing season burns since 2003, biennial burns since 2001 (reference), fire excluded since 2001, and fire excluded since 2001 and then burned during 2015, 2016, and 2017). Small mammal species richness was not affected by burn interval. Cotton rat abundance was greater in reference plots than in other treatments, whereas cotton mice (Peromyscus gossypinus) and oldfield mice were most abundant in the annually burned treatment. Three prescribed fires occurred in fire reintroduced plots prior to sampling, but these fires were insufficient to restore small mammal abundance to that of annually or biennially burned plots. Our work provides further evidence that fire is important for maintaining habitat for some small mammals and that time between fires has a species-specific effect on small mammal abundances. Thus, manipulating fire return interval is a promising tool for managing relative abundance of small mammals and likely other wildlife.

Invasive rat drives complete collapse of native small mammal communities in insular forest fragments

As tropical forests are becoming increasingly fragmented, understanding the magnitude and time frame of biodiversity declines is vital for 21st century sustainability goals. Over three decades, we monitored post-isolation changes in small mammal species richness and abundance within a forest landscape fragmented by the construction of a dam in Thailand.1,2 We observed the near-complete collapse of species richness within 33 years, with no evidence of a recolonization effect across repeatedly sampled islands. Our results further revealed a decline in species richness as island size decreased and isolation time increased, accelerated by the increasing dominance of the ubiquitous Malayan field rat, Rattus tiomanicus. This species was already hyper-abundant on smaller islands in the initial surveys (1992-1994, 66% of individuals) but became monodominant on all islands, regardless of island size, by the most recent survey (2020, 97%). Our results suggest that insular forest fragments are highly susceptible to rapid species loss, particularly due to the competitive nature of Rattus accelerating the rate at which extinction debts are paid. To mitigate these impacts, reducing the extent of habitat degradation, as triggered by fragmentation and exacerbated by isolation time, can help to sustain native biodiversity while averting Rattus hyper-abundance.

Evaluation of fine-scale environmental heterogeneity and its effect on terrestrial mammal diversity in a grassland in the Chihuahuan Desert

Environmental heterogeneity is expected to increase the richness and diversity of species. The aim of this study is to identify environmental elements that influence the richness and diversity of small, medium and large species of mammals. For the sampling of mammals, camera and Sherman traps were used at 18 sampling stations. For vegetation sampling, eight large-scale explanatory variables were selected in a 1000 m2 plot at each station. The diversity (H’) of habitats (heterogeneity) and species were measured using the Shannon–Wiener diversity index. To relate the heterogeneity and environmental variables with species richness for small, medium and large mammals, a generalised linear model (GLM) was used while considering the Poisson probability distribution. A multiple linear regression model was used for data with normal distributions. The results suggested that environmental elements could favour rodent richness but may have a negative effect on community evenness and some environmental variables that are related to the diversity of rodent species and the species richness of medium and large mammals. It was concluded that the relationship between environmental heterogeneity and mammal richness is complex and that the response to the biotic elements of the landscape is diverse and different for each species.

Age and Fieldwork Experience Increase Brazilian University Students’ Ability to Identify Wild Mammals

A lack of engagement with the natural environment can reduce awareness of issues surrounding environmental and biodiversity conservation. Therefore, to increase students’ awareness, science teachers should develop activities related to biodiversity, bringing students into closer connection with the natural environment. This study evaluated the ability of 115 Brazilian university students’ to identify native and alien wild mammals. Patterns in university students’ ability to identify species were predicted by a combination of variables (university-level, age, gender, experience linked to countryside, family farming, fishing, and hunting). Students correctly identified alien mammals more frequently than native mammals. We found distinct groups of species in function of students’ experience (university-level, age group, fishing, and hunting). In addition, we found that the correct identification of native species was mainly associated with older male students who go regularly to the countryside, and participate in activities linked to farming, fishing, and hunting. Our findings support those from previous studies that show fieldwork classes are essential to increase the contact of an increasingly urbanized society with the local natural environment. We suggest that inclusion of fieldwork is necessary for the development of university students’ awareness regarding the richness of native mammal species and consequently, the importance of their conservation.

Relationships between livestock grazing intensity and mammal predator-prey: A study case in Copo National Park in the dry Chaco forests

Extensive livestock ranching is one of the main drivers of habitat degradation in terrestrial communities in the dry Chaco forest (Argentina). Grazing intensity could differentially affect native mammals and their interactions, which could impact both, native mammal communities and livestock production systems. Here, we determined how the activity index of grey foxes Lycalopex gymnocercus and capture abundance and richness of small mammals vary along a grazing intensity gradient in a particular region of the dry Chaco forest (Copo National Park, Argentina). Track plots were used to estimate the activity index of foxes and cattle, and Sherman traps for small mammals. Fresh scats were collected to analyse the diet of foxes and to assess possible changes in predator-prey dynamics. Fruit availability and shrub density were measured in 6 plots of 2 m × 50 m. We used generalized linear mixed models, Spearman’s nonparametric rank correlation, Chi-squared test, and Spearman’s partial correlation coefficient to analyse the potential effects of grazing intensity. We found that the activity index of foxes increased (0.06 ± 0.018) while small mammal abundance (-0.08 ± 0.024) and species richness decreased (rs = -0.94) with increasing grazing intensity. However, the proportion of scats with mammalian remains decreased with increasing grazing intensity. Also, we did not find a strong partial correlation between foxes and small mammals when we controlled for grazing intensity. This suggests that the abundance and diversity of small mammals in the study area are determined more by grazing intensity than by predator-prey interactions. Grazing intensity could negatively affect small mammals, but not through changes in fruit availability or shrub density, but possibly by affecting grass cover. Consequently, foxes’ activity could increase to meet caloric intake requirements. Our results suggest that specific cattle management recommendations depend on the wildlife species that serves as a conservation target. We recommend testing whether reducing cattle load can make this productive activity compatible with wildlife conservation in dry Chaco forests.

Winter conditions structure extratropical patterns of species richness of amphibians, birds and mammals globally

AbstractAimThe aim was to derive global indices of winter conditions and examine their relationships with species richness patterns outside of the tropics.LocationAll extratropical areas (>25° N and 25° S latitudes), excluding islands.Time period2000–2018.Major taxa studiedAmphibians, birds and mammals.MethodsWe mapped three global indices of winter conditions [number of days of frozen ground (length of frozen ground winter); snow cover variability; and lack of subnivium (below‐snow refuge)] from satellite data, then used generalized additive models to examine their relationships with species richness patterns derived from range data.ResultsLength of frozen ground winter was the strongest predictor of species richness, with a consistent cross‐taxonomic decline in species richness occurring beyond 3 months of winter. It also often outperformed other environmental predictors of species richness patterns commonly used in biodiversity studies, including climate variables, primary productivity and elevation. In areas with ≥3 months of winter conditions, all three winter indices explained much of the deviance in amphibian, mammal and resident bird species richness. Mammals exhibited a stronger relationship with snow cover variability and lack of subnivium than the other taxa. Species richness of fully migratory species of birds peaked at c. 5.5 months of winter, coinciding with low species richness of residents.Main conclusionsOur study demonstrates that winter structures latitudinal and elevational gradients of extratropical terrestrial species richness. In a rapidly warming world, tracking the seasonal dynamics of frozen ground and snow cover will be essential for predicting the consequences of climate change on species, communities and ecosystems. The indices of winter conditions we developed from satellite imagery provide an effective means of monitoring these dynamics into the future.

Eurasian beaver – A semi-aquatic ecosystem engineer rearranges the assemblage of terrestrial mammals in winter

There is increasing awareness of the ecosystem engineering services provided by recovering populations of Eurasian beaver. By modifying aquatic environments, this species has a significant, positive influence on biodiversity. Beaver activity affects not only aquatic ecosystems but also terrestrial habitats and organisms. Our study compares and evaluates the species richness and activity of terrestrial mammals in winter at beaver ponds (N = 65) and randomly-selected reference sites along nearby watercourses unmodified by beavers (N = 65) in Poland (central Europe). Mammal assemblages were investigated near pond/watercourse edges, and also at some distance from them. The species richness of mammal and numbers of their tracks were respectively 25% and 33% greater on the beaver than on the reference sites. The higher species richness on beaver sites extended to areas 40–60 m distant from ponds, devoid any signs of beaver activity. Twenty-three mammal species were recorded on beaver sites (mean species richness 3.8 ± 1.6 SD), and 20 on reference ones (3.0 ± 1.5 SD). The numbers of tracks of grey wolf, least weasel and European polecat were higher on beaver than reference sites. Mammal species richness and activity were related to the existence of beaver ponds, but were also correlated with the numbers of snags and coverage of grass, bramble and coniferous saplings in neighbouring terrestrial habitats. Large and small carnivores occurred more frequently and were more active on beaver sites. The frequencies of occurrence of mesocarnivores, mesoherbivores and small herbivores were correlated with habitat characteristics, regardless of whether beavers were present or not. Our results highlight the fact that both pond creation and the habitat changes resulting from the presence of beavers rearrange the occurrence and activity of the terrestrial mammal assemblage.