Habitat of the endangered salt marsh harvest mouse (Reithrodontomys raviventris) in San Francisco Bay

Understanding habitat associations is vital for conservation of at‐risk marsh‐endemic wildlife species, particularly those under threat from sea level rise. We modeled environmental and habitat associations of the marsh‐endemic, Federally endangered salt marsh harvest mouse (Reithrodontomys raviventris, RERA) and co‐occurrence with eight associated small mammal species from annual trap data, 1998–2014, in six estuarine marshes in North San Francisco Bay, California. Covariates included microhabitat metrics of elevation and vegetation species and cover; and landscape metrics of latitude–longitude, distance to anthropogenic features, and habitat patch size. The dominant cover was pickleweed (Salicornia pacifica) with 86% mean cover and 37 cm mean height, and bare ground with about 10% mean cover. We tested 38 variants of Bayesian network (BN) models to determine covariates that best account for presence of RERA and of all nine small mammal species. Best models had lowest complexity and highest classification accuracy. Among RERA presence models, three best BN models used covariates of latitude–longitude, distance to paved roads, and habitat patch size, with 0% error of false presence, 20% error of false nonpresence, and 20% overall error. The all‐species presence models suggested that within the pickleweed marsh environment, RERA are mostly habitat generalists. Accounting for presence of other species did not improve prediction of RERA. Habitat attributes compared between RERA and the next most frequently captured species, California vole (Microtus californicus), suggested substantial habitat overlap, with RERA habitat being somewhat higher in marsh elevation, greater in percent cover of the dominant plant species, closer to urban areas, further from agricultural areas, and, perhaps most significant, larger in continuous size of marsh patch. Findings will inform conservation management of the marsh environment for RERA by identifying best microhabitat elements, landscape attributes, and adverse interspecific interactions.     

Fine‐scale habitat preferences and habitat partitioning by three mycophagous mammals in tropical wet sclerophyll forest,north‐eastern Australia

Abstract Fine‐scale habitat preferences of three co‐occurring mycophagous mammals were examined in a tropical wet sclerophyll forest community in north‐eastern Australia. Two of the three mammal species responded to fine‐scale variation in vegetation and landform around individual trap locations. At a broad scale, the northern bettong (Bettongia tropica), an endangered marsupial endemic to the Australian wet tropics region, showed a preference for ridges over mid‐slopes and gullies, irrespective of forest type. In contrast, the northern brown bandicoot (Isoodon macrourus), a widespread marsupial, displayed a preference for Eucalyptus woodland over adjacent Allocasuarina forest, irrespective of topographic category. The giant white‐tailed rat (Uromys caudimaculatus), a rodent endemic to the wet tropics, showed no particular preference for either forest type or topographic category. A multiple regression model of mammal capture success against three principal habitat gradients constructed from 21 habitat variables using principal component analysis indicated strong species‐specific preferences for fine‐scale vegetation assemblages. Bettongs preferred areas of Eucalyptus woodland with sparse ground cover, low densities of certain grass species, high density of tree stems and few pig diggings. Bandicoots, in contrast, favoured areas in both forest types with dense ground cover, fewer tree stems and greater numbers of pig diggings; that is, characteristics least favoured by bettongs. The striking differences in fine‐scale habitat preferences of these two mammals of similar body size and broad habitat requirements suggest a high degree of fine‐scale habitat partitioning. White‐tailed rats did not show preference for any of the habitat gradients examined.     

Habitat structure is more important than vegetation composition for local‐level management of native terrestrial reptile and small mammal species living in urban remnants: A case study from Brisbane,Australia

Abstract As urban areas continue to expand and replace natural and agricultural landscapes, the ability to manage and conserve native wildlife within urban environments is becoming increasingly important. To do so we first need to understand species' responses to local‐level habitat attributes in order to inform the decision‐making process and on‐ground conservation actions. Patterns in the occurrence of native terrestrial reptile and small mammal species in 59 sites located in remnant urban habitat fragments of Brisbane City were assessed against local‐level environmental characteristics of each site. Cluster analysis, multidimensional scaling ordination, and principal axis correlation were used to investigate relationships between species' occurrences and environmental characteristics. Native reptiles were most strongly associated with the presence of termite mounds, a high amount of fallen woody material, and a moderate amount of weed cover. Native small mammals were most strongly associated with the presence of grass trees (Xanthorrhoea spp.), and both reptiles and small mammals were negatively influenced by increased soil compaction. Significant floristic characteristics were considered to be important as structural, rather than compositional, habitat elements. Therefore, habitat structure, rather than vegetation composition, appears to be most important for determining native, terrestrial reptile and small mammal species assemblages in urban forest fragments. We discuss the management implications in relation to human disturbances and local‐level management of urban remnants.     

Chainsawing for conservation: Ecologically informed tree removal for habitat management

Summary In many ecosystems, increases in vegetation density and the resulting closure of forest canopies are threatening the viability of species that depend upon open, sunlight‐exposed habitats. Consequently, we need to develop management strategies that recreate open habitats while minimizing the impacts on non‐target areas. Selective logging creates canopy gaps, but may result in undesirable effects in other respects. Thus, chainsaws have not been a popular tool for conservation. We conducted a landscape‐scale experiment to test whether selective tree removal can restore patch‐level habitat quality for Australia’s most endangered snake (Hoplocephalus bungaroides) and its main prey (the lizard Oedura lesueurii). We selectively removed canopy trees surrounding 25 overgrown rock outcrops and compared the resultant habitat structure and abiotic conditions to 30 overgrown, shady outcrops and 20 open, sunny outcrops. Removing vegetation decreased canopy cover by 19% in experimental plots and increased incident radiation and thermal regimes. These changes increased the availability of suitable shelter sites for our target species by 131%. At the landscape scale, our manipulations had a trivial effect on forest habitat; by increasing the area of sun‐exposed outcrops, we decreased forest cover by <0.1%. Our results show that targeted canopy removal can increase the availability of sun‐exposed habitat patches for endangered species in biologically meaningful ways. Thus, selective tree felling may be an effective conservation tool for open‐habitat specialists threatened by vegetation overgrowth.     

Habitat Selection by Prairie Dogs in a Disturbed Landscape at the Edge of Their Geographic Range

ABSTRACT Although habitat attributes of black-tailed prairie dog (Cynomys ludovicianus) colonies have been described for central and northern portions of the species' geographic range, little is known about these associations at the southern edge of this species' distribution. Because high-quality habitats are expected to be scarcer at the edge of the species' geographic range, different patterns of habitat selection might emerge in these populations. We analyzed habitat selection by black-tailed prairie dogs in a human-disturbed mosaic of desert grasslands and shrublands in northwestern Chihuahua, Mexico. We contrasted 151 used and 133 unused habitat units producing 11 case-control logistic regression models to explain site occupancy by prairie dogs with different combinations of environmental variables. Prairie dogs from Chihuahua occupy sites similar in most respects to sites in more northern regions, although these prairie dogs appear to be more tolerant of increased shrub density and reduced herbage cover. We found that site occupancy was best modeled by positive effects of soil moisture level, cover of forbs, cover of unpalatable vegetation, cover of bare ground, and amount of prairie-dog colony area within 1 km and by the inverse of altitude, shrub density, herbage height, and amount of hostile habitat within 1 km. The 2 most significant variables were herbage height and shrub density, which might reflect the prominent role that visibility plays in habitat selection by prairie dogs. In contrast, we found weak evidence that human features have significant impacts on site occupancy by prairie dogs. Our results support the prediction that environmental conditions of sites used by prairie dogs in edge regions partially differ from those observed in more northern latitudes. We suggest that reserve managers focus conservation efforts on areas with short vegetation, low density of shrubs, and high herbage cover, conditions that could be promoted by controlled burns, herbage mowing, and mechanical removal of shrubs.     

Influence of within‐patch habitat quality on high‐Andean Polylepis bird abundance

Habitat restoration strategies for fragmented high Andean forest landscapes must consider the influence of within‐patch habitat quality on bird abundance. I examined vegetation and bird abundance at three locations within a highly fragmented Polylepis forest landscape in the Cordillera Vilcanota, southern Peru. Across the landscape, there was significant variation in the vegetation structure of Polylepis forest patches of different size categories, especially in terms of tree girth, tree height, tree density, and canopy vegetation structure. Principal Component Analysis extracted five factors of habitat quality, which together accounted for 74.2% of the variability within 15 habitat variables. Polylepis bird species differed in their responses to habitat quality but, overall, variation in Polylepis bird abundance was not fully captured by the range of habitat quality variables. Tall, dense vegetation cover was clearly important for 11 conservation‐important species, a high density of large trees was important for 10 species and primary forest ground cover was important for eight species. Habitat quality exhibited no significant influence on the abundance of only one species –Asthenes urubambensis. The abundance of seven species was associated with lower elevation forest, but only one species was associated with higher elevation forest. Management of habitat quality in large and medium remnant forest patches throughout the Cordillera Vilcanota, particularly in the 3800–4200 m elevation range, will be a cornerstone in ensuring the persistence of the majority of conservation‐important bird species populations.     

Identifying key habitats for the conservation of Bonelli's Eagle Aquila fasciata using radiotracking

Identifying the priority habitats of endangered species is crucial to implementing effective conservation actions. We characterize the key habitats used by Bonelli's Eagle Aquila fasciata, an umbrella and flagship species that is endangered in Mediterranean countries. We radiotracked 17 breeding individuals (10 males and seven females) in Catalonia (NE Iberian Peninsula) and used compositional analysis to determine the key habitats in home‐ranges of both sexes. The main habitats identified within the home‐range area were scrubland, coniferous forests, cropland, sclerophyllous forests, rock outcrops and urban areas, with little difference in habitat use between the sexes. Bonelli's Eagles preferred rocky habitats as breeding areas and scrubland as foraging areas, as these hold the highest abundance of their main prey, Rabbits Oryctolagus cuniculus and Red‐legged Partridges Alectoris rufa. Habitat selection varied seasonally in foraging areas: scrubland was the most preferred habitat type during the breeding season, whereas rocky areas were preferred during the non‐breeding season (although scrubland was also highly selected). Urban areas were avoided both as breeding and as foraging areas. Home‐range size was inversely correlated with the proportion of scrubland, suggesting that this is a key habitat for Bonelli's Eagle. To conserve this species effectively, policies that ensure the preservation of the cliffs used as breeding sites, as well as suitable management of the scrubland used for foraging, should be implemented in the areas inhabited by this species. The promotion of traditional land uses and management techniques that will enhance open areas in Mediterranean landscapes should in the future play an essential role in the conservation of Bonelli's Eagle in Mediterranean habitats.     

How to deal with ground truthing affected by human‐induced habitat change?: Identifying high‐quality habitats for the Critically Endangered Red Siskin

Species distribution models (SDM) can be valuable for identifying key habitats for conservation management of threatened taxa, but anthropogenic habitat change can undermine SDM accuracy. We used data for the Red Siskin (Spinus cucullatus), a critically endangered bird and ground truthing to examine anthropogenic habitat change as a source of SDM inaccuracy. We aimed to estimate: (1) the Red Siskin's historic distribution in Venezuela; (2) the portion of this historic distribution lost to vegetation degradation; and (3) the location of key habitats or areas with both, a high probability of historic occurrence and a low probability of vegetation degradation. We ground‐truthed 191 locations and used expert opinion as well as landscape characteristics to classify species' habitat suitability as excellent, good, acceptable, or poor. We fit a Random Forest model (RF) and Enhanced Vegetation Index (EVI) time series to evaluate the accuracy and precision of the expert categorization of habitat suitability. We estimated the probability of historic occurrence by fitting a MaxLike model using 88 presence records (1960–2013) and data on forest cover and aridity index. Of the entire study area, 23% (20,696 km²) had a historic probability of Red Siskin occurrence over 0.743. Furthermore, 85% of ground‐truthed locations had substantial reductions in mean EVI, resulting in key habitats totaling just 976 km², in small blocks in the western and central regions. Decline in Area of Occupancy over 15 years was between 40% and 95%, corresponding to an extinction risk category between Vulnerable and Critically Endangered. Relating key habitats with other landscape features revealed significant risks and opportunities for proposed conservation interventions, including the fact that ongoing vegetation degradation could limit the establishment of reintroduced populations in eastern areas, while the conservation of remaining key habitats on private lands could be improved with biodiversity‐friendly agri‐ and silviculture programs.     

Habitat selection of the long‐nosed bandicoot,Perameles nasuta (Mammalia,Peramelidae), in a patchy urban environment

Habitat selection in an omnivorous marsupial, the long‐nosed bandicoot, Perameles nasuta Geoffroy, was investigated in an urban environment with both natural and highly modified habitats at North Head, New South Wales, Australia. Habitat use at both macro‐ and microhabitat scales was determined using live‐trapping, and P. nasuta was shown to be a habitat specialist at this site. At night, animals used open grass macrohabitats disproportionately more for foraging than other macrohabitats. Trap‐revealed macrohabitat use was supported by radiotracking three males. Lack of understorey and absence of leaf litter were the major microhabitat features affecting habitat choice, although soil type probably also had some effect. Open areas may provide a more abundant and/or accessible food supply for P. nasuta, although better manoeuvrability or increased visibility to detect predators may also be important. Diurnal nest sites, located using radiotracking, were primarily in dense scrub vegetation, often comprising introduced species of plants. The dependence of P. nasuta on: (i) dense undergrowth for diurnal nesting and temporary nocturnal sheltering; and (ii) open areas for foraging indicates the importance of conserving a mosaic of open and dense vegetation to ensure the continued persistence of this endangered population at North Head.     

Habitat selection by a threatened desert amphibian

Habitat degradation and fragmentation are major drivers of amphibian declines. The loss of environmental features that allow for movement between water sources may be particularly detrimental for amphibians in arid environments. Climate changes will increase the importance of microhabitats to amphibians. Enhancing areas to facilitate movement may be a necessary conservation strategy for many animal species that depend on wetlands, including federally threatened Chiricahua leopard frogs (Lithobates chiricahuensis). Habitat preferences of this frog species are not well understood. We sought to better understand fine‐scale habitat selection, to inform conservation of Chiricahua leopard frogs. We conducted our study on the Ladder Ranch, a privately owned working bison ranch in New Mexico, USA that supports a large proportion of the remaining Chiricahua leopard frogs in the state. We attached radio transmitters to 44 frogs during summer 2014. We located each frog daily for up to 8 weeks (median = 30 days). We assessed fine‐scale habitat selection by comparing characteristics at each frog location and a random location 5 m away using conditional logistic regression. Frogs preferred features that likely reduce desiccation, even after accounting for the presence of water. Frogs selected areas with more low‐lying cover, especially aquatic vegetation and woody debris, a tree overstory, and a mud substrate. We recommend managing potential movement corridors for Chiricahua leopard frogs by ensuring the presence of muddy creek bottoms, woody debris, riparian overstory, low‐lying ground cover, and pools. Microclimates created by these features seem especially valuable given warming temperatures and modified precipitation regimes, resulting in decreased surface water, soil moisture, and vegetation cover. Retaining or creating preferred habitat features and microclimates in areas between water sources may increase connectivity among isolated populations of Chiricahua leopard frogs and could improve persistence and recovery of other water‐obligate species in arid landscapes.     

Living quarters of a living fossil—Uncovering the current distribution pattern of the rediscovered Hula painted frog (Latonia nigriventer) using environmental DNA

One of the greatest challenges of effective conservation measures is the correct identification of sites where rare and elusive organisms reside. The recently rediscovered Hula painted frog (Latonia nigriventer) has not been seen for many decades and was therefore categorized extinct. Since its rediscovery in 2011, individuals from the critically endangered species have been found, with great effort, only in four restricted sites. We applied the environmental DNA (eDNA) approach to search for new populations of the Hula painted frog in suitable aquatic habitats. We further used the eDNA data to classify the landscape factors associated with the species distribution and to predict its suitable habitats. We sampled 52 aquatic sites in the Hula Valley during the spring of 2015 and 2016 and amplified the samples with a species‐specific qPCR assay. DNA of the Hula painted frog was detected in 22 of the sites, all of which clustered within three main areas. A boosting classification model showed that soil type, vegetation cover and the current and former habitats are all key predictors of the frog's current distribution. Intriguingly, the habitat suitability models reveal a high affinity of the species to its long‐lost habitat of the historical wetlands. Our findings encourage a series of informed searches for new populations of this threatened frog and provide guidance for future conservation management programmes. In the era of global conservation crisis of amphibians, developing the eDNA approach, a reliable detection method for many critically endangered and elusive amphibians, is of particular importance.     

Capybara (Hydrochoerus hydrochaeris) distribution in agroecosystems: a cross-scale habitat analysis

Aim The aim of this study was to understand the spatial distribution of capybara (Hydrochoerus hydrochaeris) according to habitat attributes, using a multiscale approach based on fine‐ and broad‐scale variables in agroecosystems. Location Piracicaba river basin, south‐eastern Brazil (22°00′–23°30′ S; 45°45′–48°30′ W). Methods Potential habitats for capybara were selected in order to evaluate species presence/absence from October 2001 to December 2002. In each site, habitat attributes were sampled in the field (fine scale) and from GIS maps (broad scale) in terms of their presence or absence close to water. The variability of land cover between study sites was described by principal components analysis. Chi‐square tests were calculated for capybara presence/absence and the presence of each habitat attribute. A linear discriminant function analysis was used to describe to what extent the species’ presence could be explained by habitat attributes. Results The species presence was predominantly related to flat open areas (slope ranging from 0% to 6%) (χ² = 37.054, d.f. = 4, P < 0.001), covered by sugar cane or cultivated pasture (χ² = 84.814, d.f. = 9, P < 0.001). Terrain curvature, water meadows, aquatic vegetation, forest cover and open areas resulted in the best combination of variables, explaining 69.7% of capybara occurrence in the study sites in this river basin. Main conclusions Capybaras are widespread in the Piracicaba river basin, except in elevated areas. The spatial distribution of capybara was associated with the main types of land cover in the river basin – sugar cane plantations or pasture – both key food sources for capybara. This probably explains the species’ recent abundance in the region, since an intensive process of landscape alteration has taken place in this region owing to the expansion of agriculture in recent decades. These results may be useful in understanding the relationship between recent landscape modifications and the species’ population expansion in agroecosystems.     

Contrasting habitat use of morphologically similar bat species with differing conservation status in south‐eastern Australia

The east‐coast free‐tailed bat Mormopterus norfolkensis Gray, 1839 is a threatened insectivorous bat that is poorly known and as such conservation management strategies are only broadly prescribed. Insectivorous bats that use human‐modified landscapes are often adapted to foraging in open microhabitats. However, few studies have explored whether open‐adapted bats select landscapes with more of these microhabitat features. We compared three morphologically similar and sympatric, molossid bats (genus Mormopterus) with different conservation status in terms of their association with vegetation, climate, landform and land‐use attributes at landscape and local habitat element scales. We predicted that these species would use similar landscape types, with semi‐cleared and low density urban landscapes used more than forested and heavily cleared landscapes. Additionally, we explored which environmental variables best explained the occurrence of each species by constructing post‐hoc models and habitat suitability maps. Contrary to predictions, we found that the three species varied in their habitat use with no one landscape type used more extensively than other types. Overall, M. norfolkensis was more likely to occur in low‐lying, non‐urban, riparian habitats with little vegetation cover. Mormopterus species 2 occupied similar habitats, but was more tolerant of urban landscapes. In contrast, Mormopterus species 4 occurred more often in cleared than forested landscapes, particularly dry landscapes with little vegetation cover. The extensive use of coastal floodplains by the threatened M. norfolkensis is significant because these habitats are under increasing pressure from human land‐uses and the predicted increase in urbanization is likely to further reduce the amount of suitable habitat.     

Modeling ecological minimum requirements for distribution of greater sage‐grouse leks: implications for population connectivity across their western range,U.S.A

Greater sage‐grouse Centrocercus urophasianus (Bonaparte) currently occupy approximately half of their historical distribution across western North America. Sage‐grouse are a candidate for endangered species listing due to habitat and population fragmentation coupled with inadequate regulation to control development in critical areas. Conservation planning would benefit from accurate maps delineating required habitats and movement corridors. However, developing a species distribution model that incorporates the diversity of habitats used by sage‐grouse across their widespread distribution has statistical and logistical challenges. We first identified the ecological minimums limiting sage‐grouse, mapped similarity to the multivariate set of minimums, and delineated connectivity across a 920,000 km² region. We partitioned a Mahalanobis D² model of habitat use into k separate additive components each representing independent combinations of species–habitat relationships to identify the ecological minimums required by sage‐grouse. We constructed the model from abiotic, land cover, and anthropogenic variables measured at leks (breeding) and surrounding areas within 5 km. We evaluated model partitions using a random subset of leks and historic locations and selected D² (k = 10) for mapping a habitat similarity index (HSI). Finally, we delineated connectivity by converting the mapped HSI to a resistance surface. Sage‐grouse required sagebrush‐dominated landscapes containing minimal levels of human land use. Sage‐grouse used relatively arid regions characterized by shallow slopes, even terrain, and low amounts of forest, grassland, and agriculture in the surrounding landscape. Most populations were interconnected although several outlying populations were isolated because of distance or lack of habitat corridors for exchange. Land management agencies currently are revising land‐use plans and designating critical habitat to conserve sage‐grouse and avoid endangered species listing. Our results identifying attributes important for delineating habitats or modeling connectivity will facilitate conservation and management of landscapes important for supporting current and future sage‐grouse populations.     

Determining the efficacy of camera traps,live capture traps,and detection dogs for locating cryptic small mammal species

Metal box (e.g., Elliott, Sherman) traps and remote cameras are two of the most commonly employed methods presently used to survey terrestrial mammals. However, their relative efficacy at accurately detecting cryptic small mammals has not been adequately assessed. The present study therefore compared the effectiveness of metal box (Elliott) traps and vertically oriented, close range, white flash camera traps in detecting small mammals occurring in the Scenic Rim of eastern Australia. We also conducted a preliminary survey to determine effectiveness of a conservation detection dog (CDD) for identifying presence of a threatened carnivorous marsupial, Antechinus arktos, in present‐day and historical locations, using camera traps to corroborate detections. 200 Elliott traps and 20 white flash camera traps were set for four deployments per method, across a site where the target small mammals, including A. arktos, are known to occur. Camera traps produced higher detection probabilities than Elliott traps for all four species. Thus, vertically mounted white flash cameras were preferable for detecting the presence of cryptic small mammals in our survey. The CDD, which had been trained to detect A. arktos scat, indicated in total 31 times when deployed in the field survey area, with subsequent camera trap deployments specifically corroborating A. arktos presence at 100% (3) indication locations. Importantly, the dog indicated twice within Border Ranges National Park, where historical (1980s–1990s) specimen‐based records indicate the species was present, but extensive Elliott and camera trapping over the last 5–10 years have resulted in zero A. arktos captures. Camera traps subsequently corroborated A. arktos presence at these sites. This demonstrates that detection dogs can be a highly effective means of locating threatened, cryptic species, especially when traditional methods are unable to detect low‐density mammal populations.     

Threat categorisation and conservation prioritisation of floristic diversity in the Indian Himalayan region: A state of art approach from Manali Wildlife Sanctuary

Strategies have been suggested by many conservationists to conserve biodiversity at regional, national and global levels. However, conservation strategies developed in the past were mostly based on qualitative attributes or one or two attributes. In the Himalayan region biodiversity varies from aspect to aspect, habitat to habitat and community to community therefore, location specific studies are required for its conservation and management. In the present study an approach has been developed to prioritise species at local level using six conservation attributes. Threat categorisation of the floristic diversity was undertaken based on Conservation Priority Index. Of the total 637 species of vascular plants recorded, 10 species were categorised as critically endangered; 15 species as endangered and 31 species as vulnerable. Two species as critically endangered, seven species as endangered and three species as vulnerable according to IUCN have been also recorded which indicated the importance of the sanctuary. Maximum threatened species were found in altitudinal zones 2000–2800 m and sites dominated by Betula utilis and Rhododendron campanulatum in forest and alpine zones, respectively. The two factors of over exploitation and habitat degradation have been identified as major threats to the floristic diversity. Therefore, monitoring of population and habitats, development of conventional protocol; establishment of species in-situ conditions and akin habitats and replication of this approach in other parts of Indian Himalayan Region have been suggested.     

Cascading biodiversity and functional consequences of a global change–induced biome switch

Aim At a regional scale, across southern Africa, woody thickening of savannas is becoming increasingly widespread. Using coupled vegetation and faunal responses (ants), we explore whether major changes in woody cover in savannas represent an increase in the density of savanna trees (C₄ grass layer remains intact) or a ‘regime shift’ in system state from savanna to thicket (=dry forest) where broad‐leaved, forest‐associated trees shade out C₄ grasses. Location Hluhluwe Game Reserve, South Africa. Methods We sampled paired open (low woody cover) and closed (high cover that have undergone an increase in tree density) sites. Vegetation was sampled using belt transects, and a combination of pitfall trapping and Winkler sampling was used for ants. Results Closed habitats did not simply contain a higher density of woody savanna species, but differed significantly in structure, functional composition (high prevalence of broad‐leaved trees, discontinuous C₄ grasses) and system properties (e.g. low flammability). Ant assemblage composition reflected this difference in habitat. The trophic structure of ant assemblages in the two habitats revealed a functional shift with much higher abundances of predatory species in the closed habitat. Main conclusions The predominance of species with forest‐associated traits and concomitant reduction of C₄ grasses in closed sites indicate that vegetation has undergone a shift in fundamental system state (to thicket), rather than simply savanna thickening. This biome shift has cascading functional consequences and implications for biodiversity conservation. The potential loss of many specialist savanna plant species is especially concerning, given the spatial extent and speed of this vegetation switch. Although it is not clear how easily the habitat switch can be reversed and how stable the thicket habitats are, it is likely in the not‐too‐distant future that conservation managers will be forced to make decisions on whether to actively maintain savannas.     

Habitat preferences of small mammals in tropical open-forest of the Northern Territory

Pattern analysis was used to investigate the habitat preferences of five small mammal species in tropical open-forest of the Northern Territory. Fifty-one sites were classified by faunal abundance and the groups examined for significant differences in vegetation structural attributes and plant species in both dry and wet seasons. The omnivore Isoodon macrourus showed strong association with floristic and vegetation structural attributes only in the dry season, when areas with a dense understorey of small trees and shrubs and a high percentage of leaf litter cover were favoured. Of the two primarily carnivorous species, Antechinus bellus was related strongly with floristic and structural attributes in both seasons and showed a consistent preference for areas with relatively dense low-level foliage (< 2m). By contrast, Dasyurus hallucatus was associated more with the structurally simple open-forest types. Of the two mainly herbivorous species Mesembdomys gouldii showed associations only withfioristics in both seasons, while the habitat relationships of Trichosurus arnhemensis were very weak due to its low abundance in the study area. The number and strength of animal/habitat relationships were greatest in the dry season. Forest types with dense mid-level foliage and abundant hollow logs and leaf litter had the greatest mammal richness and abundance; these areas may be critical to the survival of local mammal populations. A comparison of site-groups, defined independently on the basis of fauna, floristics or structure, showed that animal groups overlapped one to six of the habitat groups. The animal's perception of s‘habitat’ may thus differ from that of humans, or that defined by measurement of habitat attributes.     

Cape ground squirrels as ecosystem engineers: modifying habitat for plants,small mammals and beetles in Namib Desert grasslands

Burrowing and foraging of semi‐fossorial rodents can affect species distribution and composition. Ground squirrels dig large burrow systems for refuge from predators and temperature extremes. Burrowing and foraging around burrows by squirrels may affect habitat and resource distributions for other organisms. We examined the impact of Cape ground squirrels (Xerus inauris) on vegetation, small mammals and beetles during winter and summer in grasslands on the edge of the Namib Desert. At each burrow system and paired control site without burrows, we estimated plant cover and height using quadrats (N = 8 paired sites), small mammal abundance and species richness using mark‐recapture techniques (N = 8 paired sites) and beetle abundance and species richness using pitfall traps (N = 6 paired sites, winter only). Squirrel burrowing and foraging activities resulted in lower plant cover and height, higher small mammal abundance and lower beetle abundance and species richness. Squirrels also reduced more plant cover in winter compared to summer, but had no effect on small mammal species richness. Furthermore, plant cover and height were higher in summer, whereas small mammal abundance and species richness were higher in winter. Our results suggest that Cape ground squirrels are important ecosystem engineers that influence plant and animal communities in the Namib Desert grasslands.     

Diversity of medium and large mammals in the Loka Abaya National Park,southern Ethiopia

We evaluated the richness, diversity, and composition of the medium and large mammal community in the Loka Abaya National Park (LANP), southern Ethiopia, and how these parameters differ among four habitat types: wooded grassland, riverine forest, hilly scrubland and wetland, and between seasons. We recorded a total of 2,573 individual animals of 28 medium and large mammal species in the park. This included three globally threatened species: the endangered African wild dog (Lycaon pictus), the vulnerable Leopard (Panthera pardus), and Hippopotamus (Hippopothamus amphibius). Season had little effect on species richness, diversity, and composition both across and within habitat types. However, species richness across seasons was significantly different among the four habitat types, in the declining order of the following: wooded grassland > riverine forest > hilly scrubland > wetland. The strongest similarity in species composition, both across and within seasons, was found between wooded grassland and riverine forest. In terms of relative abundance, mammal assemblage of the wooded grassland and wetland habitats had more evenly distributed number of species with different relative abundance categories. Overall, Anubis Baboon (Papio anubis), Grivet Monkey (Chlorocebus aethiops), and Greater Kudu (Tragelephus strepsiceros) were the three most abundant species across habitat types. In conclusion, findings of our study reveal that LANP plays an important role in Ethiopia's mammal conservation. Our findings will serve as baseline information for managers of the park to make effective conservation decisions and as a baseline for researchers wishing to conduct related ecological studies.