Sylvia Ortmann

• PhD
• Senior Researcher at Leibniz Institute for Zoo and Wildlife Research

The assimilation, retention, and release of nutrients by animals fundamentally shapes their physiology and contributions to ecological processes (e.g., zoogeochemistry). Yet, information on the transit of nutrients through the bodies of large mammals remains scarce. Here, we examined how sodium (Na), a key element for animal health and ecosystem fu...

Vocal production learning is a convergently evolved trait in vertebrates. To identify brain genomic elements associated with mammalian vocal learning, we integrated genomic, anatomical and neurophysiological data from the Egyptian fruit-bat with analyses of the genomes of 215 placental mammals. First, we identified a set of proteins evolving more s...

Current knowledge of cancer genomics remains biased against noncoding mutations. To systematically search for regulatory noncoding mutations, we assessed mutations in conserved positions in the genome under the assumption that these are more likely to be functional than mutations in positions with low conservation. To this end, we use whole-genome...

Ruminants differ in the pattern how small particles and liquids pass through their gastrointestinal tract, and in particular their reticulorumen (RR). Based on that they may be classified into 'moose-type' and 'cattle-type' species (smaller and larger differences between particle and liquid passage, respectively). The ratio between the retention of...

Protein-coding differences between species often fail to explain phenotypic diversity, suggesting the involvement of genomic elements that regulate gene expression such as enhancers. Identifying associations between enhancers and phenotypes is challenging because enhancer activity can be tissue-dependent and functionally conserved despite low seque...

Annotating coding genes and inferring orthologs are two classical challenges in genomics and evolutionary biology that have traditionally been approached separately, limiting scalability. We present TOGA (Tool to infer Orthologs from Genome Alignments), a method that integrates structural gene annotation and orthology inference. TOGA implements a d...

Human accelerated regions (HARs) are conserved genomic loci that evolved at an accelerated rate in the human lineage and may underlie human-specific traits. We generated HARs and chimpanzee accelerated regions with an automated pipeline and an alignment of 241 mammalian genomes. Combining deep learning with chromatin capture experiments in human an...

Thousands of genomic regions have been associated with heritable human diseases, but attempts to elucidate biological mechanisms are impeded by an inability to discern which genomic positions are functionally important. Evolutionary constraint is a powerful predictor of function, agnostic to cell type or disease mechanism. Single-base phyloP scores...

The precise pattern and timing of speciation events that gave rise to all living placental mammals remain controversial. We provide a comprehensive phylogenetic analysis of genetic variation across an alignment of 241 placental mammal genome assemblies, addressing prior concerns regarding limited genomic sampling across species. We compared neutral...

We examined transposable element (TE) content of 248 placental mammal genome assemblies, the largest de novo TE curation effort in eukaryotes to date. We found that although mammals resemble one another in total TE content and diversity, they show substantial differences with regard to recent TE accumulation. This includes multiple recent expansion...

Conserved genomic sequences disrupted in humans may underlie uniquely human phenotypic traits. We identified and characterized 10,032 human-specific conserved deletions (hCONDELs). These short (average 2.56 base pairs) deletions are enriched for human brain functions across genetic, epigenomic, and transcriptomic datasets. Using massively parallel...

We reconstruct the phenotype of Balto, the heroic sled dog renowned for transporting diphtheria antitoxin to Nome, Alaska, in 1925, using evolutionary constraint estimates from the Zoonomia alignment of 240 mammals and 682 genomes from dogs and wolves of the 21st century. Balto shares just part of his diverse ancestry with the eponymous Siberian hu...

Species persistence can be influenced by the amount, type, and distribution of diversity across the genome, suggesting a potential relationship between historical demography and resilience. In this study, we surveyed genetic variation across single genomes of 240 mammals that compose the Zoonomia alignment to evaluate how historical effective popul...

Zoonomia is the largest comparative genomics resource for mammals produced to date. By aligning genomes for 240 species, we identify bases that, when mutated, are likely to affect fitness and alter disease risk. At least 332 million bases (~10.7%) in the human genome are unusually conserved across species (evolutionarily constrained) relative to ne...

Understanding the regulatory landscape of the human genome is a long-standing objective of modern biology. Using the reference-free alignment across 241 mammalian genomes produced by the Zoonomia Consortium, we charted evolutionary trajectories for 0.92 million human candidate cis-regulatory elements (cCREs) and 15.6 million human transcription fac...

Sheep with a relatively low methane yield were observed to have shorter fluid and particle mean retention times (MRT). Because the application of pilocarpine, a saliva stimulant, was successful in reducing retention times in ruminants in previous studies, we applied this substance to sheep, expecting a reduction in MRT and methane yield. Three non-...

Wildlife parasite communities are important for an OneHealth approach. The external environment impacts host-associated communities directly and via the hosts. Hosts in poor body condition are more susceptible to infection and parasite mode of transmission will affect occurrence: rural environments with better availability of intermediate hosts fav...

High fluid turnover in the rumen has been shown beforewas indicated to elevate the harvest of microbial yield from the forestomach. Microbial synthesis consumes metabolic hydrogen, competing with methanogenesis. Accordingly, iIn animals as well as in vitro continuous culture systems, high fluid turnover was linked to decreased methane yield [1, 2]....

Background Animal personality has emerged as a key concept in behavioral ecology. While many studies have demonstrated the influence of personality traits on behavioral patterns, its quantification, especially in wild animal populations, remains a challenge. Only a few studies have established a link between personality and recurring movements with...

Both in vitro and animal studies indicated that a higher dilution rate is related to a more efficient microbial synthesis and a lower methane (CH4) yield. The latter could be a consequence of the former, as an increase in microbial cell synthesis offers an alternative hydrogen sink competing with methanogenesis. To test this assumption in live anim...

Spatial and temporal variability in the availability of food resources will lead to variation in a species’ diet, which can then influence patterns of space use, sociality, and life history characteristics. Despite such potential impacts, little information is available about dietary variability for some species with large geographical ranges. Here...

Background Animal personality has emerged as a key concept in behavioral ecology. While many studies have demonstrated the influence of personality traits on behavioral patterns, its quantification, especially in wild animal populations, remains a challenge. Only a few studies have established a link between personality and recurring movements with...

Sieve analyses of hindgut contents of horses as well as observations in horses where plastic markers had been applied to a caecal cannula suggested that there may be a discrimination by particle size in the passage or retention of digesta. Here, we performed a similar experiment with five caecum‐cannulated horses (562 ± 31 kg) fed a constant amount...

Numerous studies have examined whether the primary and/or secondary sex ratio in mammals, including humans, deviates from an equilibrium of 1:1. Although effect size in the sex ratio variation is expected to be low, a large sample size allows the identification of even small deviations from parity. In this study, we investigated whether the sex rat...

While information on individual differences in digesta mean retention time (MRT) might be interesting when selecting phenotypes for digestive efficiency, MRT measurements are prohibitively labour‐intensive for large‐scale application. Therefore, more easily measured proxies of MRT might be helpful. We used the opportunity of an experiment applying...

Simple Summary Understanding the resilience of primate populations to the threat of agricultural expansion is critical for effective conservation. Based on individual monitoring from morning to evening of wild chimpanzees in and around a protected area, we showed that the availability of maize at the forest edge had little effect on their activity...

Although many plants are dispersed by wind and seeds can travel long distances across unsuitable matrix areas, a large proportion relies on co-evolved zoochorous seed dispersal to connect populations in isolated habitat islands. Particularly in agricultural landscapes, where remaining habitat patches are often very small and highly isolated, mobile...

On the one hand, the greater kudu (Tragelaphus strepsiceros) is a strict browser and would therefore be expected to display a ‘moose-type’ digestive physiology with a comparatively low rumen fluid throughput, a low ratio of small particle to fluid mean retention time (MRT) in the reticulorumen (RR), and relatively unstratified RR contents. On the o...

Although many plants are dispersed by wind and seeds can travel long distances across unsuitable matrix areas, a large proportion relies on co-evolved zoochorous seed dispersal to connect populations in isolated habitat islands. Particularly in agricultural landscapes, where remaining habitat patches are often very small and highly isolated, mobile...

A new and uniquely structured matrix of mammalian phenotypes, MaTrics ( Ma mmalian Tr aits for Comparative Genom ics ) in a digital form is presented. By focussing on mammalian species for which genome assemblies are available, MaTrics provides an interface between mammalogy and comparative genomics. MaTrics was developed within a project aimed to...

The inactivation of ancestral protein‐coding genes (gene loss) can be associated with phenotypic modifications. Within placental mammals, repeated losses of PNLIPRP1 (gene inhibiting fat digestion) occurred preferentially in strictly herbivorous species, while repeated NR1I3 losses (gene involved in detoxification) occurred preferentially in strict...

Studying species interactions and niche segregation under human pressure provides important insights into species adaptation, community functioning and ecosystem stability. Due to their high plasticity in behaviour and diet, urban mesocarnivores are ideal species for studying community assembly in novel communities. We analysed the spatial and temp...

In temperate habitats, the vegetation onset in spring affects the life cycle activities of large her-bivores. For one species of large herbivore, roe deer (Capreolus capreolus), parturition is tied to peak resource availability. However, recent long-term studies of the parturition date of roe deer found only limited support for its earlier occurren...

Intrinsic to several hypotheses explaining the evolution of foraging behavior complexity, such as proto-tool use, is the assumption that more complex ingestive behaviors are adaptations allowing individuals to access difficult to procure but nutritionally or energetically rewarding foods. However, nutritional approaches to understanding this comple...

Nonstaple food is a food resource which sole consumption does not allow the maintenance of regular physiological functions, thus constituting a minor portion of an individual's diet. Many primates consume nonstaple food such as meat, insects, and fungi. Hypotheses on the dietary importance of nonstaple food include its role as fallback food and as...

This manual has been developed in the framework of the project ‘Identifying genomic loci underlying mammalian phenotypic variability using Forward Genomics’ which was funded by the Leibniz Gemeinschaft (SAW-2016-SGN-2). The project brought together an interdisciplinary scientific network covering the fields of morphology (Work Modules M1/M2, ‘Pheno...

A new and uniquely structured matrix of mammalian phenotypes, MaTrics ( Ma mmalian Tr aits for Comparative Genom ics ) is presented in a digital form. By focussing on mammalian species for which genome assemblies are available, MaTrics provides an interface between mammalogy and comparative genomics. MaTrics was developed as part of a project to li...

Epigenetic modifications, of which DNA methylation is the most stable, are a mechanism conveying environmental information to subsequent generations via parental germ lines. The paternal contribution to adaptive processes in the offspring might be crucial, but has been widely neglected in comparison to the maternal one. To address the paternal impa...

Abstract Mammalian species express a broad variety in the shape of their extrahepatic biliary tract. While a gall bladder is present in many species, others are lacking this organ. Evolutionary driving forces for these differences have not been determined yet, and organ-specific pathologies might present potentially influencing factors. We reviewed...

Various feeds for ruminants have been identified that help to mitigate the greenhouse gas methane. However, even when there has been success in suppressing absolute methane emissions, intake, digestibility, and performance often decline in parallel. Ideal dietary levels of effective feeds would reduce methane production without affecting performanc...

Some carnivores are known to survive well in urban habitats, yet the underlying behavioral tactics are poorly understood. One likely explanation for the success in urban habitats might be that carnivores are generalist consumers. However, urban populations of carnivores could as well consist of specialist feeders. Here, we compared the isotopic spe...

The influence of phenol-rich dietary grapeseed extract on performance, energy and nitrogen (N) balance and methane production was determined in 16 lambs and 13 goat kids (Body weight: 20.5 and 19.0 kg, 2 months of age, Day 1 of study). Half of the animals received a concentrate containing grapeseed extract, the others received concentrate without g...

The way that fluids and particles move through the forestomach of a ruminant is species-specific, and can be used to classify ruminants according to their digestive physiology into ‘moose-types’ (with little difference in fluid and small particle passage) and ‘cattle-types’ (where fluids move through the forestomach much faster than small particles...

Methane (CH 4 ) production is a ubiquitous, apparently unavoidable side effect of fermentative fibre digestion by symbiotic microbiota in mammalian herbivores. Here, a data compilation is presented of in vivo CH 4 measurements in individuals of 37 mammalian herbivore species fed forage-only diets, from the literature and from hitherto unpublished m...

Since heritability of CH4 emissions in ruminants was demonstrated, various attempts to generate large individual animal CH4 data sets have been initiated. Predicting individual CH4 emissions based on equations using milk mid-infrared (MIR) spectra is currently considered promising as a low-cost proxy. However, the CH4 emission predicted by MIR in i...

Monitoring metabolic activity in wild living animals has become of particular interest in the field of ecological research. Methods for the repeated non-invasive sampling of individuals are needed. Thyroid hormones (TH) are involved in the regulation of metabolic activity, and their measurement can be used as a proxy to monitor metabolic changes. D...

The aim of the study was to determine the effect of fructose supplementation in the diet on feed intake, nutrient digestibility and digesta retention time in Reeves's muntjac (Muntiacus reevesi), a browsing cervid. In Experiment 1, six adult males of Reeves's muntjac were used in a replicated 3 × 3 Latin square design and fed a diet consisting of d...

Background Expansion of brain tissue and development of advanced cognitive skills are characteristic traits of human evolution. Their emergence has been causally linked to the intake of nutrients that promote brain development and iodine is considered a critical resource. Rich sources of iodine exist in coastal areas and evolutionary scenarios asso...

Ruminants have been classified as having a ‘moose-type’ or ‘cattle-type’ digestive physiology. ‘Cattle-type’ ruminants have a clear difference in the mean retention time (MRT) of fluid vs. small particles in the reticulorumen (RR), with a high ‘selectivity factor’ (SF=MRTparticle/ MRTfluid,>1.80), and are typically grazers and intermediate feeders....

Ruminants are classified into three groups, according to their feeding behaviour: browsers, intermediate feeders and grazers. Corresponding to their dietary preferences, multiple morphological and physiological adaptations have been described, resulting in another classification: ‘moose-type’ and ‘cattle-type’ ruminants. Digesta retention patterns...

The digestive tract of animals, and the patterns how passage markers are excreted from them, have been fruitfully compared to chemical reactor models from engineering science. An important characteristic of idealized reactor models is the smoothness of the curves plotting marker concentrations in outflow (i.e., faeces) over time, which is the resul...

Limited physiological measurements exist for the digestive physiology of porcupines. We measured CH4 emission in three captive Indian crested porcupines (Hystrix indica; 16.1 ± 2.7 kg) fed a diet of pelleted lucerne, and measured feed intake, digestibility, and digesta mean retention time (MRT) of a solute and three particle markers (<2, 10 and 20...

Polyphenols are known to affect digestion of ruminants, whereas there is little information about their metabolic effects. In a 2 × 2-factorial experiment the effects of supplementing a phenolic grapeseed extract were compared in 11 East Friesian dairy sheep and 9 Saanen goats. The concentrate supplemented with 7.4 g/100 g DM grapeseed extract had...

The capybara (Hydrochoerus hydrochaeris), the largest living rodent, probably has a “mucus‐trap” colonic separation mechanism. To test this hypothesis, we measured the mean retention time of a solute marker (MRTSolute), 2 mm (MRT2 mm), 10 mm (MRT10 mm), and 20 mm (MRT20 mm) particle markers and nutrient digestibility in adult captive capybaras (27–...

Although it is known that most herbivores produce methane (CH4), CH4 emissions in rodents are generally considered negligible and have rarely been measured in live animals. We measured CH4 emission in four captive juvenile nutria (Myocastor coypus) fed a diet of pelleted lucerne, as well as food intake, digestibility, and digesta mean retention tim...

Space use in mammals may be influenced not only by their primary foods, but also by localized sources of physiologically critical resources such as sodium‐rich plants. We examined how sodium acquisition influences habitat use in mountain gorillas (Gorilla beringei) in Rwanda which have increased the amount of time they forage on community land outs...

Many small herbivores practice cecotrophy - the ingestion of special feces enriched in microbial protein by colonic separation mechanisms (CSM). In digesta passage experiments, secondary marker excretion peaks in feces are considered indicative of marker-reingestion via cecotrophy, but corroboration by behavioral observation was lacking so far. The...

Space use patterns determine access to resources necessary for survival and reproduction. Although it is recognized that the interplay between social and ecological variables shapes spacing patterns, few studies in group‐living animals have simultaneously assessed their importance in a comprehensive approach using different spatiotemporal space use...

Epigenetic modifications, of which DNA methylation is the most stable, are a mechanism conveying environmental information to subsequent generations via parental germ lines. The paternal contribution to adaptive processes in the offspring might be crucial, but has been widely neglected in comparison to the maternal one. To address the paternal impa...

A large number of small mammals practice cecotrophy, i.e. ingesting a certain fraction of their own faeces typically termed 'cecotrophs'. This behaviour is generally thought to limit metabolic losses of nitrogen, because a colonic separation mechanism (CSM) selectively accretes fine, nitrogen-rich particles (such as microbes) in the cecotrophs. Two...

The digestive physiology of cattle is characterised by comparatively long digesta mean retention times (MRTs), a particle sorting mechanism (difference in MRTs of large vs. small particles) and a distinct digesta washing (difference in MRTs between particles and fluids) in the reticulorumen (RR). How these processes mature during ontogeny, and how...

In urban areas with a high level of human disturbance, wildlife has to adjust its behavior to deal with the so called “landscape of fear.” This can be studied in risk perception during movement in relation to specific habitat types, whereby individuals trade-off between foraging and disturbance. Due to its high behavioral plasticity and increasing...

Millions of animals are killed by vehicle collisions each year. As mitigation measures, wildlife warning reflectors have become increasingly popular, although clear evidence for their effectiveness is lacking. A reason for inconclusive results in the literature may be that most previous studies on the effectiveness of wildlife warning reflectors co...

There is a discrepancy in the literature on potential digesta separation mechanisms in horses, with both a selective retention of fine and of large particles postulated in different publications. To assess the net effect of such mechanisms, we fed ponies on a hay-only diet a pulse dose of whole (unchopped) marked hay together with a solute marker,...

Physiological investigations of cervid eyes have revealed two different types of cones indicating high visual sensitivity in the ‘blue’ and ‘green’ spectral range (400-450 nm and 510-540 nm). Although detailed knowledge about light perception in large mammals is still missing, light reflecting devices such as wildlife warning reflectors are frequen...

Most wildlife species are urban avoiders, but some became urban utilizers and dwellers successfully living in cities. Often, they are assumed to be attracted into urban areas by easily accessible and highly energetic anthropogenic food sources. We macroscopically analysed stomachs of 247 wild boar (Sus scrofa, hereafter WB) from urban areas of Berl...

Description of geographic database. (PDF)

Distribution of wild boar stomach categories from urban areas of Berlin (n = 151, blue box) and rural Brandenburg (n = 96, brown box) between 2012 and 2015. Wild boar stomachs were assigned to the stomach categories Acorn (dark brown), Acorn/Fibre (olive green), Fibre (green), Maize (yellow), Mix (black)“, due to most dominant content, related to a...

Tukey posthoc test for models testing landscape within groups of different origin (rural and urban, S2 Table, Fig 3): The response variables describe the landscape within a buffer around each sample location. Human associated landscape variables (grey) are Sealing (percentage of sealed surface), houses (percentage of houses) and HumDens (Human dens...

Full model selection table for linear mixed models, testing nutrient values and food quality in stomachs of wild boar from Berlin and Brandenburg between 2012 and 2015. For different response variables, the energy amount of each stomach content was measured in KJ/g dry matter. Only the analysis of energy was split into urban and rural origin becaus...

Data table for macroscopic stomach content analysis. A general description of each stomach content is included, as well as presence (1) and absence (0) of specific items. (TXT)

Model selection table for testing landscape within groups of different origin (rural and urban). Seven sets of models were run which compared the intercept only model (“Response_null”) and a model which include the Origin as explanatory variable (model called as response). The response variables describe the landscape within a buffer around each sa...

Data table for macronutrient analysis which was used for models. (TXT)

Correlation plot to test correlation between landscape variables (Pearson’s). Percentage of agriculture (Agr), deciduous forest (DF), coniferous forest (CF), grassland (GL), houses (Ho), Sealing (Se) and human density (HD) were tested. If values are below 0.7, there is no correlation and variables can be used in the same model. (PDF)

List of candidate models for linear mixed models, testing the impact of landscape variables on the nutrient composition of wild boar. Seven sets of models were run using the following response variables: energy amount of each stomach content (measured in KJ/g dry matter); modulus of fineness (MOF, calculated after particle size determination); the...

Model selection table for linear mixed models, testing the impact of origin and stomach category on the nutrient composition of wild boar stomachs. Seven sets of models were run which compared the intercept only model (“Response_null”) and a model which include the Origin as explanatory variable (model called as response). The response variables ar...

Tukey posthoc test for models testing of landscape within groups of different origin (rural and urban, S4 Table, Fig 4): The response variables are energy amount of each stomach content (measured in KJ/g dry matter); modulus of fineness (MOF, calculated after particle size determination); the acid insoluble ash (AIA given in percent), such as amoun...

Anthropogenic food in urban wild boar. Macroscopic stomach content analysis for 247 wild boar in urban areas of Berlin and in rural Brandenburg were conducted between 2012 and 2015. Stomach contents of potential anthropogenic origin are listed here in total and separated into urban origin (blue, n = 151) and rural origin (brown, n = 96). (PDF)

Relative variable importance for linear mixed models, testing nutrient values and food quality in stomachs of wild boar from Berlin and Brandenburg between 2012 and 2015. Only models with an AICc value below 2 were used to calculate the variable importance. Only variables above 0.4 are used for the final model and visualized in Fig 4. (PDF)

Urban sprawl has resulted in the permanent presence of large mammal species in urban areas, leading to human–wildlife conflicts. Wild boar Sus scrofa are establishing a permanent presence in many cities in Europe, with the largest German urban population occurring in Berlin. Despite their relatively long‐term presence, there is little knowledge of...

Although it is well-known that retrograde transport of urine fills the caeca of birds with fluid and small particles, the function of avian caeca is still not fully understood. We measured mean retention times (MRT) of solute (cobalt-EDTA, Co), small particle (< 2 mm, chromium-mordanted fibre, Cr) and large particle (8 mm, cerium-marked fibre, Ce)...

Eastern gorillas (Gorilla beringei) are among the few mammal species that seasonally consume large quantities of young bamboo shoots, which are a rich source of energy. Here, we document how the consumption of bamboo shoots coincides with changes in behavior of adult mountain gorillas (Gorilla beringei beringei) monitored by the Dian Fossey Gorilla...

Discovering the Genomic Basis of Morphological and Physiological Differences between Mammalian Species with Forward Genomics Michael Hiller1,2, Hermann Ansorge3, Triantafyllos Chavakis4, Jörns Fickel5, Peter Giere6, Peter Grobe7, Jochen Hampe8, Thomas Lehmann3, Sylvia Ortmann5, Irina Ruf3, Clara Stefen3, Elly Tanaka4, Lars Vogt9, Heiko Stuckas3 1...

Enteric methane (CH 4 ) production is a side-effect of herbivore digestion, but it is unknown whether CH 4 itself influences digestive physiology. We investigated the effect of adding CH 4 to, or reducing it in, the reticulorumen (RR) in a 4×4 Latin square experiment with rumen-fistulated, non-lactating cows, with four treatments: (i) control, (ii)...

Tree saplings in temperate forests world‐wide experience intense browsing from deer and other mammalian herbivores. However, when compared to insect herbivory, our knowledge about the cues that trigger mammalian‐induced defence responses in trees is limited. We studied responses of field‐grown saplings of European beech ( Fagus sylvatica L.) and Sy...

Socioecological models predict that contest competition will arise when high quality foods can be usurped or monopolized, leading to more favorable energy balances and higher reproductive success for high-ranking females. Gorillas are interesting species for studying such predictions due to the variety of ecological conditions that they experience...

To address the need to preserve current genetic diversity before it is lost forever; further studies to adapt assisted reproductive technologies to various endangered species are needed, among other things. Roe deer (Capreolus capreolus), an over abundant wild deer, can serve as model species to develop or improve sperm cryopreservation of threaten...

Milk production strategies focusing on longevity and limited use of concentrate are receiving increasing attention. To evaluate such strategies, knowledge of the development with age of animal characteristics, particularly digestion, is indispensable. We therefore investigated the development of feed intake, chewing activity, and digestion in 30 la...

The chinchilla (Chinchilla laniger) is a herbivorous hystricomorph South American rodent for which no mean digesta retention times have been reported so far. Six animals (mean body mass ± standard deviation: 513 ± 99 g) on a diet of grass hay and lucerne-based pellets were given a pulse dose of a solute (cobalt-EDTA) and a particle (chromium-mordan...

The assumption that population density restricts the foraging efficiency of individuals in the population via increased competition for resources underpins socioecological models of female social relationships in primates. We examined this assumption by comparing quantitative measures of foraging efficiency in two communities of chimpanzees (Pan tr...

Here, we compare food availability and relate this to differences in energy intake rates, time spent feeding, and daily travel distance of gorillas in the two populations. Comparative intraspecific studies investigating spatiotemporal variation in food availability can help us understand the complex relationships between ecology, behavior, and life...