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Individual specialization, when individuals exploit only a subset of resources utilized by the population, is a widespread phenomenon. It provides the basis for evolutionary diversification and can impact population and community dynamics. Both phenotypic traits and environmental conditions are predicted to influence individual specialization; however, its adaptive consequences are poorly understood, particularly among large mammalian carnivores that play an important role in shaping ecosystems. We used observations of 2,960 kills made by 49 leopards Panthera pardus in the Sabi Sand Game Reserve, South Africa, to quantify the magnitude of individual dietary specialization in a solitary large carnivore, and to examine the proximate and ultimate drivers of this behaviour. We found evidence of individual specialization in leopard diet, with respect to both the species and size of prey killed. Males tended to be more specialized than females, likely because they could access a wider range of prey due to larger body size. Similarly, individuals that encountered a greater diversity of prey tended to be more specialized. Our results confirmed that ecological opportunity was a key determinant of individual specialization; however, contrary to predictions, per capita resource availability (and by extension, intraspecific competition) did not affect the degree of specialization exhibited by individuals. Surprisingly, dietary specialization appeared to disadvantage male leopards. Specialist males overlapped with fewer resident females, had fewer cubs born on their home ranges and had fewer cubs survive to independence on their home ranges than generalist males. This may have resulted from the high degree of environmental stochasticity experienced during our study, as dietary specialization is expected to advantage individuals more during periods of resource predictability. In summary, we showed that a species usually considered to be a dietary generalist was in fact a heterogeneous collection of specialist and generalist individuals. Individual specialization is typically assumed to be maintained by disruptive and/or fluctuating selection; hence, the somewhat paradoxical coexistence of both in the same population might be explained by a dynamic evolutionary equilibrium that exists between specialists and generalists, in which each benefit under different conditions. Using leopards as a model species, this study provides novel insight into the circumstances under which individual dietary specialization manifests in mammalian carnivore populations. Importantly, it is the first assessment of the fitness consequences of dietary specialization in a large carnivore (photograph credit: James Tyrrell).

Diet studies are frequently used to improve understanding of predator ecology, potential effects of carnivores on prey populations, and competition among predators. However, field identification of carnivore scat typically relies on scat morphology, size, and contents resulting in possible subjective predator identification and potentially biased results. Advancements in noninvasive genetic sampling allow for molecular identification of predator scat, eliminating many issues associated with field identification methods. We collected scat samples once per month from June 2011 to May 2012 in western Virginia, USA, using morphological characteristics for field identification of the predator. We then used mitochondrial DNA to identify the predator species of each scat and identified prey remains visually. Using confusion matrices, we found a range of accuracy in field identification for the 3 target species: coyotes (Canis latrans; 54.0%), bobcats (Lynx rufus; 57.1%), and black bears (Ursus americanus; 95.2%), even though we only considered samples with high-confidence field identification. We found a high coyote false-positive rate (52.7%), indicating we often incorrectly identified scats as coyote (98% of misidentified bobcat scats and 75% of misidentified black bear scats were recorded as coyote in the field). This asymmetrical bias in predator identification resulted in inaccurate estimates of dietary niche breadth and overlap between competitors. Our results suggest that caution should be exercised when interpreting results from studies in which carnivore species are identified by scat morphology. Future studies should employ noninvasive genetic sampling for carnivore scat identification, especially in areas with sympatric predator species that have similar scat morphology.

The increasing popularity of carnivore and animal-based diets among athletes has generated substantial interest, despite limited direct scientific evidence supporting their efficacy and safety in sport-specific contexts. This narrative review critically evaluates the current evidence and examines the physiological, performance, and health-related implications of these dietary models in athletic populations. These dietary models, characterized by the partial or complete exclusion of plant-derived foods, are often promoted on the basis of mechanistic arguments, anecdotal reports, and extrapolations from research on ketogenic and very low-carbohydrate diets. However, their physiological relevance, long-term health implications, and compatibility with the demands of athletic training remain poorly defined. This narrative review provides a critical perspective on the current evidence related to carnivore and animal-based diets in sport, integrating findings from studies on low-carbohydrate, ketogenic, high-protein, and elimination-based dietary patterns. The analysis focuses on metabolic adaptations, body composition, exercise performance, gastrointestinal function, micronutrient adequacy, hormonal responses, and potential long-term health risks. Particular attention is given to the distinction between metabolic adaptations and functional performance outcomes, as well as to the high interindividual variability in dietary responses. The available evidence suggests that while carbohydrate restriction may induce specific metabolic adaptations, such as increased fat oxidation, these changes do not consistently translate into improved performance, particularly in high-intensity or high-volume training contexts. Moreover, the highly restrictive nature of carnivore and animal-based diets raises concerns about micronutrient deficiencies, alterations in the gut microbiota, changes in the lipid profile, and potential effects on eating behaviours, particularly in competitive athletic populations. Given the absence of well-controlled, long-term intervention studies in athletes, carnivore and animal-based diets cannot currently be recommended as safe or optimal nutritional strategies for sports performance. Rather than representing viable alternatives to established sports nutrition guidelines, these dietary models may be better understood as experimental or short-term tools within highly controlled research or diagnostic frameworks. Future research should prioritize rigorous, sport-specific study designs, long-term safety outcomes, and personalized approaches that account for individual metabolic and physiological variability.

Emerging studies in the literature describe an association between high-fat, low-carbohydrate diets and severe hypercholesterolemia consistent with the levels observed in patients with (homozygous) familial hypercholesterolemia (FH). High levels of low-density lipoprotein cholesterol (LDL-C) may result from the reduced clearance of LDL particles from the circulation, the increased production of their precursor, or a combination of both. The increased intake of (saturated) fat and cholesterol, combined with limited to no intake of carbohydrates and fiber, are the main features of diets linked to hypercholesterolemia. However, several observations in previous studies, together with our observations from our lipid clinic, do not provide a definitive pathophysiological explanation for severe hypercholesterolemia. Therefore, we review these findings and possible pathophysiological explanations as well as opportunities for future research. Altogether, clinicians should rule out high-fat, low-carbohydrate diets as a possible cause for hypercholesterolemia in patients presenting with clinical FH in whom no mutation is found and discuss dietary modifications to durably reduce LDL-C levels and cardiovascular disease risk.

Understanding the diets of carnivores is essential for resolving food web interactions and the population dynamics of both prey and predators and for designing effective strategies for species and ecosystem conservation. As effective predators, wild felids play important roles in various ecosystems, but relatively little is known about the dietary habits of many species, primarily owing to their elusive behavior. We used a DNA-based method to analyze the vertebrates and plants constituting the diet of leopard cats (Prionailurus bengalensis) in the temperate forests of the mountains of southwest China, a global biodiversity hotspot. DNA extracted from leopard cat scats was amplified with primers targeting either the vertebrate mitochondrial 12S rRNA gene (N = 25 scats) or the psbCL region of the chloroplast genome of vascular plants (N = 42 scats). The polymerase chain reaction products were sequenced and prey taxa were assigned based on sequence similarity. We identified a total of 16 taxa of vertebrate prey, with pikas (in 76% of the scats) and rodents (40%) predominating. Plant material belonging to 12 taxa was found in 76% of the samples, and the genus Solanum and subfamily Rosoideae were the most frequently detected plant taxa. The frequency of occurrence of identified plant taxa differed between the spring–summer and fall–winter months. Thus, the leopard cats in our study area have a diversified diet and are highly flexible in adapting their foraging behavior to the locally available prey. Our data suggest that preserving their natural prey base dominated by pikas and rodents may be vital for the subsistence of local populations. The high species resolution and detection sensitivity of the DNA-based method we used in this study make it a powerful and efficient tool for fine-scale analysis of complex diets.

Background: The Carnivore Diet (CD) is an almost exclusively animal-based dietary pattern that has gained increasing popularity on social media. Despite numerous health-related claims, a standardized definition is lacking, and scientific evidence regarding the long-term effects of this diet remains unclear. Methods: The literature search for this scoping review was conducted in accordance with PRISMA guidelines (PRISMA-ScR) using the databases PubMed, LIVIVO, Web of Science, and the Cochrane Library. Results: Nine human studies were included. Individual publications reported positive effects of the CD, such as weight reduction, increased satiety, and potential improvements in inflammatory or metabolic markers. At the same time, potential risks of nutrient deficiencies, particularly in vitamins C and D, calcium, magnesium, iodine, and dietary fiber, as well as elevated low-density-lipoprotein (LDL-) and total cholesterol (TC) levels, were identified, along with one case describing a deterioration in health status. Overall, the quality of evidence is very limited due to small sample sizes, short study durations, and the absence of control groups. Conclusions: The CD may offer short-term health benefits but carries substantial risks of nutrient deficiencies, reduced intake of health-promoting phytochemicals, and the development of cardiovascular disease. At this time, long-term adherence to a CD cannot be recommended.

Carnivore diet-selection studies based on scat analyses are frequently used to elucidate predator ecology, predict potential effects on prey populations, and inform management decisions. However, accuracy of results and the following inference are contingent on multiple sources of sampling error including missed detections and pseudoreplication in statistical comparisons that assume independence within scat samples. We compared a repeated-sampling occupancy framework intended to estimate detection and occurrence rates for diet items with a multinomial modeling approach intended to estimate diet selection while accounting for nonindependence of diet items within samples. Both methods allowed for multimodel inference to specifically test hypotheses about differences in diet. We applied each method to 2 example data sets, a bobcat (Lynx rufus) scat data set (n = 101) collected in western Virginia, USA, from 2011 to 2013 with morphological identification of diet items, and a coyote (Canis latrans) scat data set (n = 50) collected in Tooele County, Utah, USA, in 2014 with molecular identification of diet items, and compared results with those commonly implemented in diet studies (frequency of occurrence calculations). We found imperfect detection of diet items was not a major source of bias in either the morphological or molecular data set results, but grouping similar or indistinguishable diet items in the morphological data set affected estimates when there was heterogeneity in detection among items. Using the occupancy approach on the morphological data set demonstrated that presence or amount of some diet items could decrease detection of other items and bias occurrence estimates. Furthermore, comparing multiple models of bobcat diet using Akaike’s Information Criterion with either approach revealed no support for seasonal differences, even though traditional frequency of occurrence calculations differed by almost 10%. Thus, we suggest even moderate trends in diet based on frequency of occurrence calculations without incorporating measures of uncertainty may represent sampling error, and not true differences in diet. When detection is not conditional on other diet items, comparison of multinomial models will typically be sufficient to make accurate inference about carnivore diets without requiring additional processing of scat samples.

Background A carnivore diet is characterised by the exclusive consumption of animal foods, particularly red meat. Digital media, particularly TikTok and Instagram, often praise the health-promoting and disease-preventive properties of the carnivore diet. However, the scientific data on this form of nutrition is currently very limited. Methods After creating a coding guide with an accompanying seven-day pretest and modification, a social media analysis was conducted on the Instagram platform over a period of one month. In addition to content related to nutrition and food, aspects such as lifestyle, advertising measures, and political or social statements were also collected. The survey was conducted quantitatively through categorization, accompanied by qualitative documentation of notable findings. Results The analysis included 19 content creators (47% male, 53% female; aged 25–64) with an average of 157,758 ± 146,405 (25,200–582,000) followers. A total of 1,169 posts during the survey period showed a notable focus on health- and disease-related statements. With the exception of the strong emphasis on red meat, the nutritional and food recommendations were heterogeneous. This was accompanied by ideology-related themes, politically relevant statements, and critical portrayals of institutions such as science, politics, and industry, some of which could be classified as politically right-wing conservative. However, the data does not allow for a clear political classification. Overall, the carnivore diet was portrayed as positive. Conclusions The one-sided view of carnivore nutrition, combined with political and social content, should be viewed critically. Nutrition professionals should pay attention to social media and counteract non-evidence-based claims with scientifically sound information.

Coyote (Canis latrans) populations are expanding into urban areas, yet how their feeding ecology adapts to the wildland–urban interface remains poorly understood, particularly near megacities such as Mexico City. We evaluated coyote diet across an anthropogenic gradient in the Sierra del Ajusco, comparing a conserved site (Las Rosas) and a human‐modified site (Las Maravillas). We analyzed 198 scats collected over 1 year, using prey diversity (Shannon–Wiener H′) and network modularity (Louvain algorithm) to assess spatial and seasonal variation. Mammals dominated the diet at both sites, with Microtus mexicanus as the primary prey. Annual dietary diversity did not differ significantly between the conserved (H′ = 2.245) and modified (H′ = 2.368) sites (p = 0.2502), consistent with low network modularity (0.073). In contrast, seasonal variation differed between sites: the conserved site showed a significant shift in diet diversity (p = 0.02587), whereas the modified site did not (p = 0.6874). These results indicate that the primary effect of anthropogenic disturbance is not a change in overall diet diversity, but a buffering of seasonal variation. The year‐round availability of anthropogenic resources in the modified landscape appears to decouple coyote feeding ecology from natural seasonal cycles, with potential consequences for its ecological role. Coyote populations are expanding into urban areas, and this study examines how their diet adapts along a gradient from conserved to human‐modified habitats. Mammals dominated the diet at both sites, and there was no significant difference in annual dietary diversity between the conserved and modified areas. Anthropogenic environments reduce seasonal variation in the coyote's diet, likely due to the constant availability of human‐related food resources.

Carnivores fulfil important ecological roles in natural systems yet can also jeopardise the persistence of threatened species. Understanding their diet is, therefore, essential for managing populations of carnivores, as well as those of their prey. This study was designed to better understand the diet of an Australian apex predator, the dingo, and determine whether it poses a threat to at-risk small macropods in two floristically different yet geographically close reserves in subtropical Australia. Based on an analysis of 512 scats, dingo diets comprised 34 different prey taxa, of which 50% were common between reserves. Our findings add support to the paradigm that dingoes are opportunistic and generalist predators that prey primarily on abundant mammalian fauna. Their diets in the Border Ranges were dominated by possum species (frequency of occurrence (FOC) = 92.5%), while their diets in Richmond Range were characterised by a high prevalence of pademelon species (FOC = 46.9%). Medium-sized mammals were the most important dietary items in both reserves and across all seasons. The dietary frequency of medium-sized mammals was generally related to their availability (indexed by camera trapping); however, the avoidance of some species with high availability indicates that prey accessibility may also be important in dictating their dietary choices. Other prey categories were supplementary to diets and varied in importance according to seasonal changes in their availability. The diets included two threatened macropods, the red-legged pademelon and black-striped wallaby. Our availability estimates, together with earlier dietary studies spanning 30 years, suggest that the red-legged pademelon is resilient to the observed predation. The black-striped wallaby occurred in only two dingo scats collected from Richmond Range and was not detected by cameras so the threat to this species could not be determined. Two locally abundant but highly threatened species (the koala and long-nosed potoroo) were not detected in the dingoes’ diets, suggesting dingoes do not at present pose a threat to these populations. Our study highlights the importance of site-based assessments, population monitoring and including data on prey availability in dietary investigations.