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Abstract Efficient foraging plays a critical role in fitness, yet food choices and underlying nutritional goals vary among animals. To understand those choices and therefore the importance of different food resources, many studies estimate food preferences by applying electivity indices that account for resource availabilities. However, the general applicability of electivity indices in biologically relevant foraging scenarios is unclear. Our major aims were to find effective methods to estimate animals' food choices and to investigate long‐term food choices and underlying nutritional goals of the red colobus monkey (Piliocolobus tephrosceles) in Kibale National Park, Uganda, an endangered folivore. We used simulations of different foraging conditions to evaluate the applicability of electivity indices in biologically relevant scenarios to help interpret our results. Then, we used long‐term data collected between 2006 and 2016 on the feeding behavior and ecology of red colobus to determine the consumption frequencies of different foods and their food preferences. Based on these results and nutritional concentrations of young leaves of frequently consumed tree species, we investigated the importance of the protein‐to‐fiber ratio in their diet. Our simulations highlight limitations of electivity indices in biologically relevant foraging scenarios. Further, red colobus clearly chose young leaves over other plant parts, and, considering species and plant part, red colobus fed on many different items, but few dominated their diet. The availability and spatial distribution varied across the most consumed foods, but red colobus preferences remained mostly stable over time. Protein‐to‐fiber ratio had no association with preference but with consumption frequencies of different young leaves. The limitations of electivity indices in different foraging conditions underline the importance of comparing food preferences with consumption frequencies to assess the importance of different food resources. Our results provide a robust understanding of the food choices and nutritional goals of a leaf‐eating animal that can ultimately be used for implementing more effective conservation measures by directing habitat protection or restoration efforts toward these resources.

This study is the second in a series that examines the habitat requirements and response to logging of koalas (Phascolarctos cinereus) inhabiting tall eucalypt forests of north-east NSW. It presents the findings of koala population and habitat monitoring surveys in Pine Creek State Forest and Bongil Bongil National Park using a combination of call-counting and direct observation (spotlighting). The 6400 ha study area was mapped into 6 zones of increasing koala habitat quality by ground survey of forest structure and floristics on a 200 m grid. The accuracy of habitat definition and mapping was tested by stratified transect counts of koala calls and sightings over two consecutive years (1997–98). Average koala density increased steeply and significantly, from 0.02 – 0.20 koalas/hectare, with increasing mapped habitat quality based on increasing forest age, structural complexity, local food tree species diversity, history of prior koala occurrence and decreased past logging intensity. This relationship was driven primarily by breeding females, with the number of male koala calls weakly or uncorrelated with koala sightings and mapped habitat quality. Male koalas were more widely and uniformly distributed than females, including areas of low quality, plantation, and intensively logged forest. This finding explains the discrepancy between our results and those of other recent studies which concluded that koalas are tolerant of intensive logging based on modelling of calling male koalas and reliance on an untested assumption that male calling is indicative of female breeding success. Koala density in a subset of the highest quality habitat was relatively stable at 0.28 koalas/ha (3 hectares/koala) over the long term (1997–98 and 2012–2023). Key characteristics of the forest koala population, including low stable density, large home ranges, preference for high food tree diversity and locally unique food trees (including Allocasuarina torulosa and Syncarpia glomulifera), are not adequately explained by existing koala habitat models. We present a new paradigm to explain regional variation in koala distribution, habitat and foraging preferences based on variations in foliage chemistry (toxicity and nutritional value) determined by the duration and stability of local plant-koala interactions in response to past fire, hunting, predation and logging disturbance history. We hypothesize that koala density in stable forest populations is regulated at low levels by a combination of selected and induced increases in leaf toxicity and decreases in leaf nutrition that limit koala browsing to benign levels of about 1-2% of annual leaf production. Large home ranges, complex mature forest structure, high food tree diversity and a specialized or diverse gut microbiome may be essential to allow females to rotate and change food trees frequently to minimize induced toxicity and select individual leaves with sufficient nutrients to support breeding and lactation with minimal risk of predation. High density koala populations (> 0.6/ha) occur primarily in areas where koalas have been introduced or re-introduced to planted habitats and natural areas where aboriginal hunters and dingoes were historically present but are now absent, and where food trees have not been selected for resistance to koala browsing pressure. [ABSTRACT FROM AUTHOR]

In New South Wales, legislation governing land clearing and development as it relates to koala conservation acts to prevent the destruction of habitat containing key tree species used by koalas. The identification of these key tree species is therefore critical to koala conservation. We aimed to compile a list of tree species used by koalas within the Wollondilly Shire region and investigate tree-use preferences. We radio-collared one female and four male koalas and tracked their movements over a period of 107--195 days. We conducted surveys within each koala's home range to quantify the relative availability of each tree species, which we compared with their relative frequency of use. Koalas used 19 different tree species (17 during day, 12 during night), despite over 32 species being available. Eight species were preferentially used by one or more koalas; these were Eucalyptuts bosistoana, E. longifolia, E. puncata, E. crebra, E. globoidea, E. pilularis, E. tereticornis and Angophora flohbunda. Two species were avoided: Corymbia gummifera and Acacia decurrens. Koalas consistently used larger trees relative to their availability, and we found a general but non-significant trend towards the use of larger trees at night compared with during the day. To achieve koala conservation, it will be necessary to preserve habitat patches comprising a diverse mixture of tree species and sizes, particularly trees >35 cm diameter at breast height (DBH), and to appropriately revegetate land with these criteria in mind. [ABSTRACT FROM AUTHOR]

Changes in ambient temperature and solar radiation may affect sloths' metabolic rate and body temperature, with consequent changes in activities, postures and microhabitat selection. Although the separate effect of temperature and solar radiation on sloth's behaviour have been previously studied, the combined effect of these climatic factors on behavioural aspects of sloths has never been systematically evaluated in field conditions. Here we evaluated the influence of hourly ambient temperature variation on maned sloth (Bradypus torquatus) activities, postures and tree crown positions, under sunny and cloudy conditions; and tested if any of the animal posture and position increase their exposure to human detection. We performed 350 h of visual observation on eight maned sloths, equipped with radio‐backpacks, in northern Bahia, Brazil, recording their activities, and their resting postures and positions on tree crowns. We also recorded the time taken to visualize the sloths on 58 days to analyse if sloths' detection is affected by posture and position. Higher ambient temperature, within a range of 21–33°C, increased the sloths' activity levels in cloudy conditions but reduced their activity in sunny conditions. Increasing ambient temperature also reduced the frequency of huddled posture and increased the frequency of extended posture and permanence in the inner tree crown. Lastly, the postures and positions did not influence sloths' detectability. Thus, the direction of the temperature–activity relationship depends on climatic conditions (sunny/cloudy), and individuals rely on resting postures and positions to thermoregulate. The warmer and drier future climate, expected to occur in the northern Atlantic Forest, may impose change in the diurnal activity levels and postural pattern for this threatened species, leading maned sloths to reduce its activity on sunny and warmer days and adopting an extended posture. [ABSTRACT FROM AUTHOR]

Folivorous primates are typically considered time minimizers because the constraints of their unique digestive systems require them to spend a large portion of their activity budgets resting. However, inter- and intraspecific behavioral variation in their activity budgets may be influenced by local geographic and climatic conditions and evolutionary history. We compiled 48 studies representing ten genera, 31 species, and 50 populations to assess geographic (elevation, latitude), climatic (precipitation, temperature), and phylogenetic correlates of colobine activity budgets. Time spent resting negatively correlated with time spent feeding, moving, and socializing. Except for time spent socializing, activity budgets were independent of phylogeny, with more time spent feeding and less time resting in higher-elevation habitats and at lower temperatures. Among the four most common genera in our sample, only in Rhinopithecus did time spent feeding increase with higher elevations (range, 950–3950 m above mean sea level) and lower temperatures (range, 0.9–25 ℃). Only in Trachypithecus did time spent resting decrease with lower temperatures (range, 19–25 ℃). Our findings suggest that there are no apparent effects of geographic or climatic gradients on colobine activity budgets except for Rhinopithecus and Trachypithecus, whose activities are biased in favor of energy maximization rather than time minimization. Compared with other colobines, the ability of Rhinopithecus to adapt their activity budget at high elevations may make them less vulnerable to climate change, while the greater sensitivity of Trachypithecus to heat may make them more vulnerable to climate change. [ABSTRACT FROM AUTHOR]

Plant secondary metabolites (PSMs) can influence the consumption of particular plants by herbivores. Unsubstituted B-ring flavanones (UBFs), which are compounds found in the leaves of Eucalyptus species from the Eucalyptus subgenus (common name monocalypt), deter feeding by common brushtail possums (Trichosurus vulpecula ) when added to artificial diets at concentrations that reflect those found naturally in foliage. We hypothesised that common ringtail possums (Pseudocheirus peregrinus ) would tolerate higher UBF concentrations, because, unlike brushtail possums, they regularly eat monocalypt foliage. This proved to be the case; ringtail possums were not deterred by two different UBFs, pinocembrin and flavanone, at concentrations up to 4.7% dry matter, which is substantially higher than the concentrations that deter brushtail possums. These results extend and refine our understanding of how variation in tolerance or susceptibility to eucalypt PSMs affects the diets of sympatric marsupial folivores, potentially reducing competition for food. [ABSTRACT FROM AUTHOR]

For decades, knowledge about the endangered proboscis monkey was gleaned from limited information about their behavior from boat surveys conducted along riverbanks, where the monkeys rest during the early morning and late afternoon. This was due to the dense and swampy habitats they live in, which made them nearly impossible to track once they moved into inland forests. By conducting full‐day continuous observations on foot in riverine forests in Sabah, Borneo, Malaysia, alongside my colleagues, we produced pioneering research about this species. Conducted over a period of more than 15 years since 2005, our studies have resulted in the comprehensive collection of information about the proboscis monkey with regards to its feeding and ranging behaviors as well as novel findings about its fascinating digestive strategy of rumination and the unique functionality of its "odd‐nose." [ABSTRACT FROM AUTHOR]

The Listriodontinae were a common and widespread group of Suidae (pigs) that lived in an area extending from Portugal to China and to southern Africa. Here, we describe the new species Listriodon dukkar from Pasuda (Gujarat, India). It shares features with Li. pentapotamiae, evolved from it, and is the last representative of this lineage. The Listriodontinae flourished for about 10 million years, reached their maximum diversity and geographic extension during the Mid-Miocene Climatic Optimum (about 17–13.6 Ma), and their last records are close in age and date to ~ 9.8 Ma in the Indian Subcontinent, 9.78 Ma in Europe, and ~ 10 Ma in Africa. We review the environments in which the last listriodont lineages lived and went extinct. Their extinctions occurred against a background of increasing seasonality, vegetation change, a rise in bovid diversity and abundance, and local events, such as the European Vallesian Crisis and a dramatic drop in tragulid abundance in the Siwaliks. However, changes in the atmospheric pCO2 may have contributed to their decline and extinction in all their geographic distribution. Decreasing pCO2 is expected to have decreased sugar content and increased protein content of leaves and fruit. Hindgut fermenting Suoidea have higher protein requirements, while foregut fermenting Suoidea are more efficient in digesting sugars. Listriodontinae were probably foregut fermenters and were less well adapted in a low pCO2 world. [ABSTRACT FROM AUTHOR]

Free-ranging animals make dietary choices that affect their nutritional status and, ultimately, their health and fitness. We investigated food selection by a leaf-eating foregut-fermenting primate, the guereza (Colobus guereza), using multiple criteria, including chemical and mechanical properties, in vitro digestibility and leaf abundance, on the basis of 30 consecutive months of behavioral observations (4308 h in total) of a family group in the Kalinzu Forest, Uganda, as well as vegetation surveys. We noted that leaf toughness may be a proximate cue for the chemical properties of plant foods, especially for protein, which is an important selection factor used by primates. We also found that the in vitro digestibility of plant foods was greatly influenced by the concentrations of fiber and secondary compounds. At a broad level, none of the studied factors, including leaf chemical and mechanical properties, digestibility and abundance, affected whether guerezas consumed specific leaf items. At a more detailed level, however, protein content, digestibility and toughness were related to the percentage of foraging effort that guerezas devoted to specific items in our study site.

In socially living mammals, females often form highly differentiated and stable social relationships, commonly with genetically related individuals, which leads to social clusters within groups (i.e. matrilines). However, in primates, research on female social relationships commonly focuses on species and populations with female philopatry and the frequent occurrence of affiliative and agonistic behaviours. Therefore, our aim was to investigate the long-term patterns of female social relationships in a primate with female-biased dispersal, where affiliative and agonistic behaviours among females are rare. We analysed 9 years of continuous data from female Ugandan red colobus monkeys, Piliocolobus tephrosceles , in Kibale National Park, Uganda, and used spatial proximity to establish social networks for 3- and 6-month periods. Then, we investigated the differentiation, stability and clustering of social relationships for each of these periods using several approaches. As expected for a primate with female-biased dispersal, our results largely confirmed the absence of temporally stable social relationships and social clusters within the group. However, in about half of the analysed time periods, females formed differentiated social relationships. This indicates that factors other than dispersal patterns and within-group contest competition contribute to the formation of the ephemeral relationships, as measured by spatial proximity, among female red colobus. Therefore, our results on the patterns of female social relationships in a primate with female-biased dispersal provide important empirical insight for the refinements of theories that aim to explain social evolution in mammals. • We analysed female social relationships over 9 years in a female-dispersed primate. • Females formed differentiated relationships during half of the analysed periods. • There was little indication for temporally stable relationships among females. • Females did not form social clusters often observed in primates with matrilines. [ABSTRACT FROM AUTHOR]

Dietary protein is often considered a factor that limits the growth of primate populations. The ratio of crude protein (CP) to fiber in common mature leaves in a forest reliably predicts colobine biomass across Africa and Asia. This relationship is puzzling because CP of mature leaves is notably high in some forests, including Kibale National Park, Uganda, where mature leaves have a higher protein concentration (ca. 18% CP on a dry matter basis) than what is required for primate growth, maintenance, and reproduction. We used an in vitro assay that incorporates the role of fiber and tannins to assess the biological relevance of CP in the leaves that comprise the diets of colobines (Colobus guereza, Piliocolobus tephrosceles) in Kibale (N = 37 spp. mature leaves, 39 spp. young leaves). Relative to CP, available (digestible) protein (AP) concentrations were 50% lower in mature leaves and 38% lower in young leaves, and protein-to-fiber ratios were lower when incorporating AP. Surprisingly, leaf AP did not differ among sites within Kibale, and AP at all sites exceeded primate protein requirements. Future research, particularly in protein-rich forests like Kibale, should consider focusing on fiber, energy, and other nutritional factors to assess the relationship between colobine biomass and leaf nutritional quality. Our study expands on the way that primate ecologists measure protein, integrates several traits into a single currency of AP, and contributes to conservation management plans. [ABSTRACT FROM AUTHOR]

We explore a common feature of insect population dynamics, interspecific synchrony, which refers to synchrony in population dynamics among sympatric populations of different species. Such synchrony can arise via several possible mechanisms, including shared environmental effects and shared trophic interactions, but distinguishing the relative importance among different mechanisms can be challenging. We analyze interannual time series of population densities of the larch budmoth, Zeiraphera griseana (Lepidoptera: Tortricidae), along with six sympatric larch‐feeding folivores from a site in the European Alps 1952–1979. These species include five lepidopterans, Exapate duratella, Ptycholomoides aeriferana, Spilonota laricana, Epirrita autumnata and Teleiodes saltuum, and one hymenopteran sawfly Pristiphora laricis. We document that the highly regular oscillatory behavior (period 9–10 years) of Z. griseana populations is similarly evident in the dynamics of most of the sympatric folivores. We also find that all of the sympatric species are phase synchronized with Z. griseana populations with half of the sympatric species exhibiting nonlagged phase synchrony and three of the species exhibiting 2–5 year lags behind Z. griseana populations. We adapt a previously developed tritrophic model of Z. griseana dynamics to explore possible mechanisms responsible for observed phase synchronization. Results suggest that either shared stochastic influences (e.g., weather) or shared parasitoid impacts are likely causes of nonlagged phase synchronization. The model further indicates that observed patterns of lagged phase synchronization are most likely caused by either shared delayed induced host plant defenses or direct density‐dependent effects shared with Z. griseana. [ABSTRACT FROM AUTHOR]

Koalas are thought to have little need to drink because they gain the majority of the water that they require to survive from the water content in the leaves that they feed on. In this manuscript, we expand beyond the handful of incidental observations of koala drinking reported in the literature and describe natural koala drinking behaviour in the wild at different locations in Australia and across a range of weather conditions, discussing how koalas may have stronger reliance on free water than previously thought. [ABSTRACT FROM AUTHOR]

Background The diet of the koala (Phascolarctos cinereus) is comprised almost exclusively of foliage from the genus Eucalyptus (family Myrtaceae). Eucalyptus produces a wide variety of potentially toxic plant secondary metabolites which have evolved as chemical defences against herbivory. The koala is classified as an obligate dietary specialist, and although dietary specialisation is rare in mammalian herbivores, it has been found elsewhere to promote a highly-conserved but low-diversity gut microbiome. The gut microbes of dietary specialists have been found sometimes to enhance tolerance of dietary PSMs, facilitating competition-free access to food. Although the koala and its gut microbes have evolved together to utilise a low nutrient, potentially toxic diet, their gut microbiome has not previously been assessed in conjunction with diet quality. Thus, linking the two may provide new insights in to the ability of the koala to extract nutrients and detoxify their potentially toxic diet. Method The 16S rRNA gene was used to characterise the composition and diversity of faecal bacterial communities from a wild koala population (n = 32) comprising individuals that predominately eat either one of two different food species, one the strongly preferred and relatively nutritious species Eucalyptus viminalis, the other comprising the less preferred and less digestible species Eucalyptus obliqua. Results Alpha diversity indices indicated consistently and significantly lower diversity and richness in koalas eating E. viminalis. Assessment of beta diversity using both weighted and unweighted UniFrac matrices indicated that diet was a strong driver of both microbial community structure, and of microbial presence/absence across the combined koala population and when assessed independently. Further, principal coordinates analysis based on both the weighted and unweighted UniFrac matrices for the combined and separated populations, also revealed a separation linked to diet. During our analysis of the OTU tables we also detected a strong association between microbial community composition and host diet. We found that the phyla Bacteroidetes and Firmicutes were co-dominant in all faecal microbiomes, with Cyanobacteria also co-dominant in some individuals; however, the E. viminalis diet produced communities dominated by the genera Parabacteroides and/or Bacteroides, whereas the E. obliqua-associated diets were dominated by unidentified genera from the family Ruminococcaceae. Discussion We show that diet differences, even those caused by differential consumption of the foliage of two species from the same plant genus, can profoundly affect the gut microbiome of a specialist folivorous mammal, even amongst individuals in the same population. We identify key microbiota associated with each diet type and predict functions within the microbial community based on 80 previously identified Parabacteroides and Ruminococcaceae genomes.

Abstract Trees are large organisms that structure forest ecosystems by providing an environment for an enormous diversity of animal, microbial and plant species. As these species use trees as their common hosts, many are likely to interact with each other directly or indirectly. From studies on herbaceous plant species we know that microbes can affect the interaction of plants with herbivorous insects, for example via changes in plant metabolite profiles. The consequences of fungal colonization for tree-insect interactions are, however, barely known, despite the importance of these ecological communities. In this review we explore the interaction of leaf-inhabiting pathogenic and endophytic fungi with trees and the consequences for tree-living insect herbivores. We discuss molecular, physiological, chemical, biochemical and ecological aspects of tree-fungus interactions and summarize the current knowledge on the direct and indirect effects of tree-inhabiting fungi on insect herbivores. Our mechanistic understanding of the tripartite interaction of trees with leaf-inhabiting fungi and insect herbivores is still in its infancy. We are currently facing substantial drawbacks in experimental methodology that prevent us from revealing the effect of one single fungal species on a particular insect herbivore species and vice versa. Future studies applying a versatile toolbox of modern molecular, chemical analytical and ecological techniques in combined laboratory and field experiments will unequivocally lead to a better understanding of fungus-tree-insect interactions. [ABSTRACT FROM AUTHOR]

Background. The diet of the koala (Phascolarctos cinereus) is comprised almost exclusively of foliage from the genus Eucalyptus (family Myrtaceae). Eucalyptus produces a wide variety of potentially toxic plant secondary metabolites which have evolved as chemical defences against herbivory. The koala is classified as an obligate dietary specialist, and although dietary specialisation is rare in mammalian herbivores, it has been found elsewhere to promote a highly-conserved but low-diversity gut microbiome. The gut microbes of dietary specialists have been found sometimes to enhance tolerance of dietary PSMs, facilitating competition-free access to food. Although the koala and its gut microbes have evolved together to utilise a low nutrient, potentially toxic diet, their gut microbiome has not previously been assessed in conjunction with diet quality. Thus, linking the two may provide new insights in to the ability of the koala to extract nutrients and detoxify their potentially toxic diet. Method. The 16S rRNA gene was used to characterise the composition and diversity of faecal bacterial communities from a wild koala population (n D 32) comprising individuals that predominately eat either one of two different food species, one the strongly preferred and relatively nutritious species Eucalyptus viminalis, the other comprising the less preferred and less digestible species Eucalyptus obliqua. Results. Alpha diversity indices indicated consistently and significantly lower diversity and richness in koalas eating E. viminalis. Assessment of beta diversity using both weighted and unweighted UniFrac matrices indicated that diet was a strong driver of both microbial community structure, and of microbial presence/absence across the combined koala population and when assessed independently. Further, principal coordinates analysis based on both the weighted and unweighted UniFrac matrices for the combined and separated populations, also revealed a separation linked to diet. During our analysis of the OTU tables we also detected a strong association between microbial community composition and host diet. We found that the phyla Bacteroidetes and Firmicutes were co-dominant in all faecal microbiomes, with Cyanobacteria also co-dominant in some individuals; however, the E. viminalis diet produced communities dominated by the genera Parabacteroides and/or Bacteroides, whereas the E. obliqua-associated diets were dominated by unidentified genera from the family Ruminococcaceae. Discussion. We show that diet differences, even those caused by differential consumption of the foliage of two species from the same plant genus, can profoundly affect the gut microbiome of a specialist folivorous mammal, even amongst individuals in the same population. We identify key microbiota associated with each diet type and predict functions within the microbial community based on 80 previously identified Parabacteroides and Ruminococcaceae genomes. [ABSTRACT FROM AUTHOR]

There is a great deal of spatial and temporal variation in the availability and nutritional quality of foods eaten by animals, particularly in temperate regions where winter brings lengthy periods of leaf and fruit scarcity. We analyzed the availability, dietary composition, and macronutrients of the foods eaten by the northern‐most golden snub‐nosed monkey (Rhinopithecus roxellana) population in the Qinling Mountains, China to understand food choice in a highly seasonal environment dominated by deciduous trees. During the warm months between April and November, leaves are consumed in proportion to their availability, while during the leaf‐scarce months between December and March, bark and leaf/flower buds comprise most of their diet. When leaves dominated their diet, golden snub‐nosed monkeys preferentially selected leaves with higher ratios of crude protein to acid detergent fiber. While when leaves were less available, bark and leaf/flower buds that were high in nonstructural carbohydrates and energy, and low in acid detergent fiber were selected. Southern populations of golden snub‐nosed monkey can turn to eating lichen, however, the population studied here in this lichen‐absent area have adapted to their cool deciduous habitat by instead consuming buds and bark. Carbohydrate and energy rich foods appear to be the critical resources required for the persistence of this species in temperate habitat. The dietary flexibility of these monkeys, both among seasons and populations, likely contributes to their wide distribution over a range of habitats and environments. [ABSTRACT FROM AUTHOR]

Understanding the natural diet of species may provide useful information that can contribute to successful captive maintenance. A common problem experienced with captive foregut-fermenting primate (colobine) diets is that they are deficient in fiber and therefore highly digestible. This may contribute to gastrointestinal disorders often observed in zoos. An approach to obtain information relevant for the improvement of diets is to compare the nutrient composition of feces from free-ranging and captive individuals. In theory, fecal material can be considered a proxy for diet intake integrated over a certain period of time. We collected fecal samples from eight free-ranging proboscis monkey (Nasalis larvatus, a highly endangered colobine species) groups from a secondary forest along the Kinabatangan River and four from a mixed mangrove-riverine forest along the Garama River, Sabah, Borneo, Malaysia. We also collected fecal samples from 12 individual captive adult/sub-adult proboscis monkeys from three different zoos. We confirmed that feces from free-ranging monkeys contained more fiber and less metabolic fecal nitrogen than those from captive specimens, indicating a less digestible diet in the wild. Modifying the diets of captive colobines to include more fiber, comparable to those of free-ranging ones, may contribute to their health and survival.

Microscopic wear patterns on teeth, that is, dental microwear, are capable of recording observed dietary behaviour in a diversity of extant and extinct animals. However, recent work has questioned the utility of dental microwear at clarifying dietary behaviour, instead suggesting that dental microwear textures are reflective of grit consumed and not the dietary properties of ingested food. Some suggest that dental microwear cannot reflect the textural properties of vegetation consumed because phytoliths are too soft to form microwear. Koalas ( Phascolarctos cinereus) are model organisms for examining dental microwear formation because they consume a specialized diet consisting almost exclusively of eucalyptus leaves, which notably lack phytoliths. Here, we assess if koala dental microwear records a diet consistent with the consumption of tough leaves - despite the absence of phytoliths in their primary food source. Dental microwear texture data of koalas are consistent with tough folivorous diets, with high anisotropy values indistinguishable from folivorous primates and grazing bovids. However, koalas have significantly higher complexity (indicative of hard object feeding) than the folivorous primate Alouatta palliata, and are indistinguishable in this variable from mixed feeding and browsing bovids. While higher complexity values in koalas may result from increased dust and/or grit on the landscape in comparison to folivores that occur in wetter environments, it may also result from the mastication of woody browse. We also determined that complexity and textural fill volume are not significantly greater in drier environments - as one would predict if grit was the major contributor to dental microwear formation. Koalas may instead be selecting softer younger leaves in drier regions where water is more limited. Collectively, microwear associated with tough object feeding can be formed in the absence of phytoliths and grit may interact with food to form microwear reflective of diet, as opposed to overprinting dietary signals. [ABSTRACT FROM AUTHOR]

Aim Highly productive areas have long been hypothesized to support a greater abundance and diversity of animals than less productive areas. However, evidence for this is equivocal and, until recently, has been difficult to test at a landscape level. For the first time, we use imaging spectroscopy to investigate the relationship between plant productivity and arboreal mammal species richness and abundance at a landscape scale. Location A eucalypt forest in New South Wales, Australia. Methods Using a common index of plant productivity - normalized difference vegetation index ( NDVI) - as a proxy for available energy, we test the ability of species-energy theory and optimal foraging theory to explain variations in arboreal marsupial species richness and abundance. We obtained NDVI data from an airborne imaging spectrophotometer. Results Species richness increased in relation to NDVI among 53 eucalypt forest sites, based on five arboreal marsupial species. The presence and abundance of a eucalypt folivore specialist, Petauroides volans, increased in relation to NDVI. The relative abundance of all arboreal marsupials collectively also increased in relation to NDVI among sites, even with P. volans data excluded. In support of optimal foraging theory, the observed locations of P. volans had a higher NDVI value than the average for sampling transects. In addition, the average NDVI of eucalypt forest remnants was positively related to the overall abundance of P. volans. An important caveat is that NDVI did not explain all the variation in arboreal marsupial populations. Main conclusions Assuming that NDVI is an appropriate proxy for available energy in a eucalypt forest, our results are consistent with predictions from species-energy and optimal foraging theories. Remotely sensed measures of productivity and forage quality, used in conjunction with other important landscape characteristics, provide a potentially powerful tool to evaluate habitat and biodiversity hotspots at scales relevant to wildlife management and conservation. [ABSTRACT FROM AUTHOR]

Despite negative press reports on the effect of meat and other animal-source foods (ASFs) on human health and a vocal minority who contend that humans evolved as vegetarians, scientific evidence contradicts these views. For several million years before the development of agriculture, our ancestors were heavily reliant on ASFs as a source of energy and critical substrates such as protein and long-chain omega-3 fatty acids. Numerous lines of evidence in the anthropological literature have confirmed this scenario. Studies on ASF composition and clinical trials on ASF consumption have provided clear evidence of a requirement for meat in the diet to provide nutrients essential to health, such as Vitamin B12, long-chain omega-3 fatty acids and bioavailable forms of iron and zinc. Other studies have demonstrated that lean ASFs have a role in cholesterol-lowering diets and are important for mental function. Finally, it is possible and desirable to produce meat of a lean nature that mimics the many healthy attributes of wild-game meats and, by emphasising pasture feeding over grain feeding, this can be achieved to a large extent in Australia. Meat consumption has been associated with claims of negative health effects, along with speculation of humans evolving on a vegetarian diet. Anthropological investigation has shown that human evolution from the ape line over 3-4 million years has actually been associated with a high reliance on meat, with associated digestive-system adaptations. Today, we rely on meat in the diet for a range of specific nutrients and these can be supplied in a low-fat healthy form from a range of meat cuts. [ABSTRACT FROM AUTHOR]

Knowledge of a species' ranging patterns is vital for understanding its behavioral ecology and vulnerability to extinction. Given the abundance and even distribution of leaves in forested habitats, folivorous primates generally spend less time feeding; more time resting; have shorter day ranges; and require smaller home ranges than frugivorous primates. To test the influence of frugivory on ranging behavior, we established the activity budget and home-range size and use in a highly frugivorous population of the Borneo-endemic colobine, Presbytis rubicunda, within Sabangau tropical peat-swamp forest, Central Kalimantan, and examined relationships between fruit availability and ranging patterns. We collected 6848 GPS locations and 10,702 instantaneous focal behavioral scans on a single group between January and December 2011. The group had the largest home-range size recorded in genus Presbytis (kernel density estimates: mean = 108.3 ± SD 3.8 ha, N = 4 bandwidths). The annual activity budget comprised 48 ± SD 4.0% resting; 29.3 ± SD 3.9% feeding, 14.2 ± SD 2.5% traveling, and 0.4 ± SD 0.4% social behaviors. Mean monthly day-range length was the highest recorded for any folivorous primate (1645 ± SD 220.5 m/d). No significant relationships existed between ranging variables and fruit availability, and ranging behaviors did not vary significantly across seasons, potentially owing to low fluctuations in fruit availability. Our results suggest that colobine monkeys maintain larger than average ranges when high-quality food resources are available. Their extensive range requirements imply that protecting large, contiguous tracts of habitat is crucial in future conservation planning for Presbytis rubicunda. [ABSTRACT FROM AUTHOR]

Because of the large-scale destruction of Borneo's rainforests on mineral soils, tropical peat-swamp forests (TPSFs) are increasingly essential for conserving remnant biodiversity, particularly in the lowlands where the majority of habitat conversion has occurred. Consequently, effective strategies for biodiversity conservation are required, which rely on accurate population density and distribution estimates as a baseline. We sought to establish the first population density estimates of the endemic red langur ( Presbytis rubicunda) in Sabangau TPSF, the largest remaining contiguous lowland forest-block on Borneo. Using Distance sampling principles, we conducted line transect surveys in two of Sabangau's three principle habitat sub-classes and calculated group density at 2.52 groups km−2 (95% CI 1.56-4.08) in the mixed-swamp forest sub-class. Based on an average recorded group size of 6.95 individuals, population density was 17.51 ind km−2, the second highest density recorded in this species. The accessible area of the tall-interior forest, however, was too disturbed to yield density estimates representative of the entire sub-class, and P. rubicunda was absent from the low-pole forest, likely as a result of the low availability of the species' preferred foods. This absence in 30% of Sabangau's total area indicates the importance of in situ population surveys at the habitat-specific level for accurately informing conservation strategies. We highlight the conservation value of TPSFs for P. rubicunda given the high population density and large areas remaining, and recommend 1) quantifying the response of P. rubicunda to the logging and burning of its habitats; 2) surveying degraded TPSFs for viable populations, and 3) effectively delineating TPSF sub-class boundaries from remote imagery to facilitate population estimates across the wider peat landscape, given the stark contrast in densities found across the habitat sub-classes of Sabangau. Am. J. Primatol. 75:837-847, 2013. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Southeast Asia's lowland dipterocarp forests experience supra-annual 'mast' fruiting and flowering events, in which the majority of trees reproduce simultaneously at irregular intervals, with extensive intervening periods of very low primate food availability. This scarcity of food results in a negative energy balance and a reliance on 'fallback foods' in some primate species. By contrast, ombrogenous tropical peat-swamp forests are non-masting, and show lower variability of food availability. We sought to test the influence of fruit availability on primate diet and preference in peat-swamp habitats and assess whether it differs from masting forests. We collected behavioral-dependent feeding data on three adult females in a group of red langurs ( Presbytis rubicunda: Colobinae) between January and December 2011 in Sabangau tropical peat-swamp forest, Central Kalimantan, Indonesia, as colobine monkeys are adaptated for folivory, and are therefore generally considered less reliant on temporally variable fruits than monogastric primates. We documented the highest level of granivory recorded to date in colobine monkeys: mean annual diet comprised 76.4% seeds and 7.3% other fruit parts; 7.7% young and 2.5% mature leaves; 2.8% flowers; 2.6% piths, and <1% on other minor food items. Fruit availability was fairly constant throughout the year and fruit parts were consumed at consistently higher levels than expected based on availability, confirming that fruit is preferred. Leaves and flowers were consumed consistently less than expected and thus are not preferred. There were no significant correlations between preferred food availability and consumption of potential fallback foods, suggesting that reliance on fallback foods did not occur in Sabangau during the study period. Furthermore, consumption of fruit was not significantly correlated with its availability. Our findings suggest that the relatively constant availability of fruit in this habitat affords P. rubicunda regular access to a nutritionally superior food, and that reliance on fallback foods is therefore not required. Am. J. Primatol. 75:848-859, 2013. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Movement behaviour plays an important role in many ecological interactions. As animals move through the environment, they generate movement patterns, which are a combined result of landscape characteristics and species-specific behaviour. Measuring these ranging patterns is being facilitated by technological advances in collection methods, such as GPS collars, that are capturing movement on finer spatial and temporal scales. We propose the use of a novel spatiotemporal analytical framework (ST-BBD), based on the beta-binomial distribution (BBD) model, to measure small-scale aggregation in animal movement data sets, including two simulated and three collected primate data sets. We use this approach to distinguish different habitat uses of three primate species (red colobus, Procolobus rufomitratus, black howler, Alouatta pigra, and spider monkey, Ateles geoffroyi) and quantify their specific use of the landscape in space and in time, using a parameter of the BBD that measures the variation in sites visited on a landscape. We found that estimates of aggregation in habitat use were higher in the frugivorous spider monkey, compared to the more folivorous howler monkey, and that in the red colobus, aggregation in site visits was dependent on group size and food availability. Applications of this framework to animal movement data could be useful in understanding ecological systems where habitat use is an important factor, such as the relationships between hosts and parasites, or parent plants and seed dispersers. [Copyright &y& Elsevier]

Ecologists want to explain why populations of animals are not evenly distributed across landscapes and often turn to nutritional explanations. In seeking to link population attributes with food quality, they often contrast nutritionally positive traits, such as the concentration of nitrogen, against negative ones, such as fibre concentration, by using a ratio of these traits. This specific ratio has attracted attention because it sometimes correlates with the biomass of colobine primates across sites in Asia and Africa. Although empirically successful, we have identified problems with the ratio that may explain why it fails under some conditions to predict colobine biomass. First, available nitrogen, rather than total nitrogen, is nutritionally important, while the presence of tannins is the major factor reducing the availability of nitrogen in browse plant species. Second, tannin complexes inflate measures of fibre. Finally, simple ratios may be unsound statistically because they implicitly assume isometric relationships between variables. We used data on the chemical composition of plants from three continents to examine the relationships between the concentrations of nitrogen, available nitrogen, fibre and tannins in foliage and to evaluate the nitrogen to fibre ratio. Our results suggest that the ratio of the concentration of nitrogen to fibre in leaves does sometimes closely correlate with the concentration of available nitrogen. However, the ratio may give misleading results when leaves contain high concentrations of tannins. The concentration of available nitrogen, which incorporates measures of total nitrogen, dry matter digestibility and tannins, should give a better indication of the nutritional value of leaves for herbivorous mammals that can readily be extrapolated to habitats. [ABSTRACT FROM AUTHOR]

Background: Animals co-evolve with their gut microbiota; the latter can perform complex metabolic reactions that cannot be done independently by the host. Although the importance of gut microbiota has been well demonstrated, there is a paucity of research regarding its role in foliage-foraging mammals with a specialized digestive system. Results: In this study, a 16S rRNA gene survey and metagenomic sequencing were used to characterize genetic diversity and functional capability of cecal microbiota of the folivorous flying squirrel (Petaurista alborufus lena). Phylogenetic compositions of the cecal microbiota derived from 3 flying squirrels were dominated by Firmicutes. Based on end-sequences of fosmid clones from 1 flying squirrel, we inferred that microbial metabolism greatly contributed to intestinal functions, including degradation of carbohydrates, metabolism of proteins, and synthesis of vitamins. Moreover, 33 polysaccharide-degrading enzymes and 2 large genomic fragments containing a series of carbohydrate-associated genes were identified. Conclusions: Cecal microbiota of the leaf-eating flying squirrel have great metabolic potential for converting diverse plant materials into absorbable nutrients. The present study should serve as the basis for future investigations, using metagenomic approaches to elucidate the intricate mechanisms and interactions between host and gut microbiota of the flying squirrel digestive system, as well as other mammals with similar adaptations. [ABSTRACT FROM AUTHOR]

Abstract: Galactolipase, phospholipase and triacylglycerol lipase activities were measured from the midgut of six species of lepidopteran larvae, two folivores, Epiphyas postvittana (Tortricidae) and Helicoverpa armigera (Noctuidae); two granivores, Plodia interpunctella (Pyralidae) and Ephestia kuehniella (Pyrallidae); a presumptive carnivore, Galleria mellonella (Pyralidae); and a keratinophage, Tineola bisselliella (Tineidae). Galactolipase has not been previously reported in insects. Galactolipase and phospholipase activities were high in the folivores and triacylglycerol lipase activity was low, matching the high galactolipid content of leaves. Conversely, galactolipase and phospholipase activities were low, but not absent, and triacylglycerol lipase activity high in the four other non-folivorous species, matching the high acylglycerol content of their diets. These data suggest the utility of reclassification, for evolutionary studies, of phytophagous lepidoptera into two feeding classes; folivore and granivore, the latter having similarity to the fungivore line of feeders in terms of its lipase activities and ability to retrieve essential polyunsaturated long chain fatty acids from their diets. All the digestive lipases have alkaline pH optima for activity, matching the pH of the lepidopteran midgut and their amino acid content show modifications likely to stabilize the proteins in that environment. [Copyright &y& Elsevier]

Abstract: Uncertainty in recovery times of tropical forests can lead to mismanagement, such as in setting inappropriate harvesting rates or failing to achieving conservation targets. We use long-term plot data (17y) to estimate recovery times of separate forest compartments, which experienced different levels of timber extraction within Kibale National Park, Uganda. We estimate that structural recovery (basal area) of heavily logged and moderately logged compartments will take respectively 112 and 95y, when compared to adjacent mature forest. Our data suggests that recovery in terms of species composition will take significantly longer. Our estimates of structural recovery are derived from rates of change of diameter at breast height and basal area measurements which have been used traditionally as indicators of forest growth and productivity. Our results suggest that the severity of the logging has an impact on the rate of recovery, with current recovery rates estimated at 0.32m2 ha−1 y−1 in a moderately logged compartment and 0.25m2 ha−1 y−1 in heavily logged areas, highlighting the possible benefits of reduced impact harvesting in increasing long-term yields. We investigate how some representatives of the wildlife community were affected by differential recovery times and find that recovery times of frugivorous primate''s forest habitats were 2.5 times slower when compared with folivorous primates. [Copyright &y& Elsevier]