A hyaena on stilts: comparison of the limb morphology of Ictitherium ebu (Mammalia: Hyaenidae) from the Late Miocene of Lothagam, Turkana Basin, Kenya with extant Canidae and Hyaenidae.

The long, gracile morphology of the limb bones of the Late Miocene hyaenid Ictitherium ebu has led to the hypothesis that this animal was cursorial. The forelimb and femur of the holotype were compared with specimens of extant Hyaenidae and Canidae. Two morphometric methods were used. The first used measurements to calculate indices of different morphological characters. The second method involved capturing photographs of the anterior distal humerus of each specimen, mapping six landmarks on them, and calculating truss distances. These distances represent a schematic reproduction of the elbow. Multivariate statistical analysis primarily separated the data based on taxonomy, yet locomotor and habitat categories were also considered. Ictitherium ebu has an overall morphology similar to that of the maned wolf and a distal humerus reminiscent of that of the aardwolf. The long, gracile limb bones of I. ebu are suggested to be adaptations for pouncing on prey, for locomotor efficiency, and for looking over the tall grass of the open environments the animal lived in, much like the present-day maned wolf.

Alteration of the gut microbial composition of critically endangered Malayan tigers (Panthera tigris jacksoni) in captivity during enrichment phase.

BACKGROUND: Enrichment activities may influence the microbiomes of captive tigers', affecting their health, digestion, and behavior. Currently, there are few studies that address the impact of enrichment activity on tigers' health. This study aimed to determine the diversity of the gut microbiome in captive Malayan tigers at Zoo Melaka and Night Safari during the environmental enrichment phase using a metabarcoding approach. METHODS AND RESULTS: This study utilized different enrichment activities which catered for food, sensory, and cognitive enrichment. Eleven fresh fecal samples from captive Malayan tigers at Zoo Melaka and Night Safari were collected under different conditions. All samples were extracted and 16S rRNA V3-V4 region amplicon sequencing was used to characterize the gut microbiome of captive Malayan tigers subjected to various enrichment activities. Firmicutes, Actinobacteriota, and Fusobacteriota were the dominant phyla observed in the gut microbiome of captive Malayan tigers during enrichment activities. This study revealed ß-diversity significantly varied between normal and enrichment phase, however no significant differences were observed in α-diversity. This study demonstrates that environmental enrichment improves the gut microbiome of Malayan tigers because gut microbes such as Lachnoclostridium, which has anti-inflammatory effects and helps maintain homeostasis, and Romboutsia, which has a probiotic effect on the gut microbiome. CONCLUSIONS: This study provides valuable insights into the effects of enrichment activities on the gut microbiome of captive Malayan tigers, offering guidance for enhancing captive management practices aimed at promoting the health and well-being of Malayan tiger in captivity.

Drift drives the evolution of chromosome number II: The impact of range size on genome evolution in Carnivora.

Chromosome number is a fundamental genomic trait that is often the first recorded characteristic of a genome. Across large clades, a common pattern emerges: many or even most lineages exhibit relative stasis, while a handful of lineages or species exhibit striking variation. Despite recent developments in comparative methods, most of this heterogeneity is still poorly understood. It is essential to understand why some lineages have rapid rates of chromosome number evolution, as it can impact a variety of other traits. Previous research suggests that biased female meiotic drive may shape rates of karyotype evolution in some mammals. However, Carnivora exhibits variation that this female meiotic drive model cannot explain. We hypothesize that variation in effective population size may underlie rate variation in Carnivora. To test this hypothesis, we estimated rates of fusions and fissions while accounting for range size, which we use as a proxy for effective population size. We reason fusions and fissions are deleterious or underdominant and that only in lineages with small range sizes will these changes be able to fix due to genetic drift. In this study, we find that the rates of fusions and fissions are elevated in taxa with small range sizes relative to those with large range sizes. Based on these findings, we conclude that 1) naturally occurring structural mutations that change chromosome number are underdominant or mildly deleterious, and 2) when population sizes are small, structural rearrangements may play an important role in speciation and reduction in gene flow among populations.

Evolutionary patterns of cat-like carnivorans unveil drivers of the sabertooth morphology.

The sabertooth morphology stands as a classic case of convergence, manifesting recurrently across various vertebrate groups, prominently within two carnivorans clades: felids and nimravids. Nonetheless, the evolutionary mechanisms driving these recurring phenotypes remain insufficiently understood, lacking a robust phylogenetic and spatiotemporal framework. We reconstruct the tempo and mode of craniomandibular evolution of Felidae and Nimravidae and evaluate the strength of the dichotomy between conical and saber-toothed species, as well as within saber-toothed morphotypes. To do so, we investigate morphological variation, convergence, phenotypic integration, and evolutionary rates, employing a comprehensive dataset of nearly 200 3D models encompassing mandibles and crania from both extinct and extant feline-like carnivorans, spanning their entire evolutionary timeline. Our results reject the hypothesis of a distinctive sabertooth morphology, revealing instead a continuous spectrum of feline-like phenotypes in both the cranium and mandible, with sporadic instances of unequivocal convergence. Disparity peaked at the end of the Miocene and is usually higher in clades containing taxa with extreme sabertoothed adaptations. We show that taxa with saberteeth exhibit a lower degree of craniomandibular integration, allowing to exhibit a greater range of phenotypes. Those same groups usually show a burst of morphological evolutionary rate at the beginning of their evolutionary history. Consequently, we propose that a reduced degree of integration coupled with rapid evolutionary rates emerge as key components in the development of a sabertooth morphology in multiple clades.

SNAPSHOT USA 2021: A third coordinated national camera trap survey of the United States.

SNAPSHOT USA is a multicontributor, long-term camera trap survey designed to survey mammals across the United States. Participants are recruited through community networks and directly through a website application (https://www.snapshot-usa.org/). The growing Snapshot dataset is useful, for example, for tracking wildlife population responses to land use, land cover, and climate changes across spatial and temporal scales. Here we present the SNAPSHOT USA 2021 dataset, the third national camera trap survey across the US. Data were collected across 109 camera trap arrays and included 1711 camera sites. The total effort equaled 71,519 camera trap nights and resulted in 172,507 sequences of animal observations. Sampling effort varied among camera trap arrays, with a minimum of 126 camera trap nights, a maximum of 3355 nights, a median 546 nights, and a mean 656 ± 431 nights. This third dataset comprises 51 camera trap arrays that were surveyed during 2019, 2020, and 2021, along with 71 camera trap arrays that were surveyed in 2020 and 2021. All raw data and accompanying metadata are stored on Wildlife Insights (https://www.wildlifeinsights.org/), and are publicly available upon acceptance of the data papers. SNAPSHOT USA aims to sample multiple ecoregions in the United States with adequate representation of each ecoregion according to its relative size. Currently, the relative density of camera trap arrays varies by an order of magnitude for the various ecoregions (0.22-5.9 arrays per 100,000 km2), emphasizing the need to increase sampling effort by further recruiting and retaining contributors. There are no copyright restrictions on these data. We request that authors cite this paper when using these data, or a subset of these data, for publication. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the US Government.

Craniometric Characteristics of Selected Carnivora Species Kept in Captivity in Relation to Bite Force and Bending Strength of the Upper Canines.

The aim of this study was to analyse the bite forces of seven species from three carnivore families: Canidae, Felidae, and Ursidae. The material consisted of complete, dry crania and mandibles. A total of 33 measurements were taken on each skull, mandible, temporomandibular joint, and teeth. The area of the temporalis and masseter muscles was calculated, as was the length of the arms of the forces acting on them. Based on the results, the bite force was calculated using a mathematical lever model. This study compared the estimated areas of the masticatory muscles and the bending strength of the upper canines among seven species. A strong correlation was found between cranial size and bite force. The results confirmed the hypothesis that the weight of the animal and the size of the skull have a significant effect on the bite force.

The complete mitochondrial genome of Meller's mongoose (Rhynchogale melleri).

Meller's mongoose (Rhynchogale melleri) is a member of the family Herpestidae (Mammalia: Carnivora) and the sole species in the genus Rhynchogale. It is primarily found in savannas and open woodlands of eastern sub-Saharan Africa. Here, we report the first complete mitochondrial genome for a female Meller's mongoose collected in Tanzania, generated using a genome-skimming approach. The mitogenome had a final length of 16,644 bp and a total of 37 annotated genes. Phylogenetic analysis validated the placement of this species in the herpestid subfamily Herpestinae. Ultimately, the outcomes of this research offer a genetic foundation for future studies of Meller's mongoose.

Lions & sea lions & bears, oh my: utilizing museum specimens to study the ossification sequence of carnivoran taxa.

BACKGROUND: Mammalian skeletons are largely formed before birth. Heterochronic changes in skeletal formation can be investigated by comparing the order of ossification for different elements of the skeleton. Due to the challenge of collecting prenatal specimens in viviparous taxa, opportunistically collected museum specimens provide the best material for studying prenatal skeletal development across many mammalian species. Previous studies have investigated ossification sequence in a range of mammalian species, but little is known about the pattern of bone formation in Carnivora. Carnivorans have diverse ecologies, diets, and biomechanical specializations and are well-suited for investigating questions in evolutionary biology. Currently, developmental data on carnivorans is largely limited to domesticated species. To expand available data on carnivoran skeletal development, we used micro-computed tomography (micro-CT) to non-invasively evaluate the degree of ossification in all prenatal carnivoran specimens housed in the Harvard Museum of Comparative Zoology. By coding the presence or absence of bones in each specimen, we constructed ossification sequences for each species. Parsimov-based genetic inference (PGi) was then used to identify heterochronic shifts between carnivoran lineages and reconstruct the ancestral ossification sequence of Carnivora. RESULTS: We used micro-CT to study prenatal ossification sequence in six carnivora species: Eumetopias jubatus (Steller sea lion, n = 6), Herpestes javanicus (small Indian mongoose, n = 1), Panthera leo (lion, n = 1), Urocyon cinereoargenteus (gray fox, n = 1), Ursus arctos arctos (Eurasian brown bear, n = 1), and Viverricula indica (small Indian civet, n = 5). Due to the relatively later stage of collection for the available specimens, few heterochronic shifts were identified. Ossification sequences of feliform species showed complete agreement with the domestic cat. In caniforms, the bear and fox ossification sequences largely matched the dog, but numerous heterochronic shifts were identified in the sea lion. CONCLUSIONS: We use museum specimens to generate cranial and postcranial micro-CT data on six species split between the two major carnivoran clades: Caniformia and Feliformia. Our data suggest that the ossification sequence of domestic dogs and cats are likely good models for terrestrial caniforms and feliforms, respectively, but not pinnipeds.

Comparative anatomy of the caudate nucleus in canids and felids: Associations with brain size, curvature, cross-sectional properties, and behavioral ecology.

The evolutionary history of canids and felids is marked by a deep time separation that has uniquely shaped their behavior and phenotype toward refined predatory abilities. The caudate nucleus is a subcortical brain structure associated with both motor control and cognitive, emotional, and executive functions. We used a combination of three-dimensional imaging, allometric scaling, and structural analyses to compare the size and shape characteristics of the caudate nucleus. The sample consisted of MRI scan data obtained from six canid species (Canis lupus lupus, Canis latrans, Chrysocyon brachyurus, Lycaon pictus, Vulpes vulpes, Vulpes zerda), two canid subspecies (Canis lupus familiaris, Canis lupus dingo), as well as three felids (Panthera tigris, Panthera uncia, Felis silvestris catus). Results revealed marked conservation in the scaling and shape attributes of the caudate nucleus across species, with only slight deviations. We hypothesize that observed differences in caudate nucleus size and structure for the domestic canids are reflective of enhanced cognitive and emotional pathways that possibly emerged during domestication.

Anomalous origin of the right subclavian artery in a Neotropical otter (Lontra longicaudis, Olfers-1818).

The Neotropical otter (Lontra longicaudis) is a mustelid distributed geographically from Mexico to Argentina. Anomalous origins of the aortic arch branches are rarely reported in wild carnivorans. Therefore, this study aimed to report the anomalous branching of the aortic arch in one formaldehyde-fixed specimen of L. longicaudis. The aortic arch provided three branches: the bicarotid trunk and the left and right subclavian arteries. The latter passed dorsally to the esophagus toward the right side without a mark of compression at the esophagus. This is the first report of an anomalous origin of the right subclavian artery in L. longicaudis.

Heterozygosity is low where rare color variants in wild carnivores prevail.

Coat color and pattern are a distinguished feature in mammalian carnivores, shaped by climatic cycles and habitat type. It can be expressed in various ways, such as gradients, polymorphisms, and rare color variants. Although natural selection explains much of the phenotypic variation found in the wild, genetic drift and heterozygote deficiency, as prominent in small and fragmented populations, may also affect phenotypic variability through the fixation of recessive alleles. The aim of this study was to test whether rare color variants in the wild could relate to a deficiency of heterozygotes, resulting from habitat fragmentation and small population size. We present an overview of all rare color variants in the order Carnivora, and compiled demographic and genetic data of the populations where they did and did not occur, to test for significant correlations. We also tested how phylogeny and body weight influenced the presence of color variants with phylogenetic generalized linear mixed models (PGLMMs). We found 40 color-variable species and 59 rare color variants. In 17 variable phenotypic populations for which genetic diversity was available, the average A R was 4.18, H O = 0.59, and H E = 0.66, and F IS = 0.086. We found that variable populations displayed a significant reduction in heterozygosity and allelic richness compared to non-variable populations across species. We also found a significant negative correlation between population size and inbreeding coefficients. Therefore, it is possible that small effective size had phenotypic consequences on the extant populations. The high frequency of the rare color variants (averaging 20%) also implies that genetic drift is locally overruling natural selection in small effective populations. As such, rare color variants could be added to the list of phenotypic consequences of inbreeding in the wild.

Uncovering the mosaic evolution of the carnivoran skeletal system.

The diversity of vertebrate skeletons is often attributed to adaptations to distinct ecological factors such as diet, locomotion, and sensory environment. Although the adaptive evolution of skull, appendicular skeleton, and vertebral column is well studied in vertebrates, comprehensive investigations of all skeletal components simultaneously are rarely performed. Consequently, we know little of how modes of evolution differ among skeletal components. Here, we tested if ecological and phylogenetic effects led to distinct modes of evolution among the cranial, appendicular and vertebral regions in extant carnivoran skeletons. Using multivariate evolutionary models, we found mosaic evolution in which only the mandible, hindlimb and posterior (i.e. last thoracic and lumbar) vertebrae showed evidence of adaptation towards ecological regimes whereas the remaining skeletal components reflect clade-specific evolutionary shifts. We hypothesize that the decoupled evolution of individual skeletal components may have led to the origination of distinct adaptive zones and morphologies among extant carnivoran families that reflect phylogenetic hierarchies. Overall, our work highlights the importance of examining multiple skeletal components simultaneously in ecomorphological analyses. Ongoing work integrating the fossil and palaeoenvironmental record will further clarify deep-time drivers that govern the carnivoran diversity we see today and reveal the complexity of evolutionary processes in multicomponent systems.

Running, jumping, hunting, and scavenging: Functional analysis of vertebral mobility and backbone properties in carnivorans.

Carnivorans are well-known for their exceptional backbone mobility, which enables them to excel in fast running and long jumping, leading to them being among the most successful predators amongst terrestrial mammals. This study presents the first large-scale analysis of mobility throughout the presacral region of the vertebral column in carnivorans. The study covers representatives of 6 families, 24 genera and 34 species. We utilized a previously developed osteometry-based method to calculate available range of motion, quantifying all three directions of intervertebral mobility: sagittal bending (SB), lateral bending (LB), and axial rotation (AR). We observed a strong phylogenetic signal in the structural basis of the vertebral column (vertebral and joint formulae, length proportions of the backbone modules) and an insignificant phylogenetic signal in most characteristics of intervertebral mobility. This indicates that within the existing structure (stabilization of which occurred rather early in different phylogenetic lineages), intervertebral mobility in carnivorans is quite flexible. Our findings reveal that hyenas and canids, which use their jaws to seize prey, are characterized by a noticeably elongated cervical region and significantly higher SB and LB mobility of the cervical joints compared to other carnivorans. In representatives of other carnivoran families, the cervical region is very short, but the flexibility of the neck (both SB and LB) is significantly higher than that of short-necked odd-toed and even-toed ungulates. The lumbar region of the backbone in carnivorans is dorsomobile in the sagittal plane, being on average ~23° more mobile than in artiodactyls and ~38° more mobile than in perissodactyls. However, despite the general dorsomobility, only some representatives of Canidae, Felidae, and Viverridae are superior in lumbar flexibility to the most dorsomobile ungulates. The most dorsomobile artiodactyls are equal or even superior to carnivorans in their ability to engage in dorsal extension during galloping. In contrast, carnivorans are far superior to ungulates in their ability to engage ventral flexion. The cumulative SB in the lumbar region in carnivorans largely depends on the mode of running and hunting. Thus, adaptation to prolonged and enduring pursuit of prey in hyenas is accompanied by markedly reduced SB flexibility in the lumbar region. A more dorsostable run is also a characteristic of the Ursidae, and the peculiar maned wolf. Representatives of Felidae and Canidae have significantly more available SB mobility in the lumbar region. However, they fully engage it only occasionally at key moments of the hunt associated with the direct capture of the prey or when running in a straight line at maximum speed.

Symphyseal morphology and jaw muscle recruitment levels during mastication in musteloid carnivorans.

In studies of mammalian mastication, a possible relationship has been proposed between bilateral recruitment of jaw adductor muscle force during unilateral chewing and the degree of fusion of the mandibular symphysis. Specifically, species that have unfused, mobile mandibular symphyses tend to utilize lower levels of jaw adductor force on the balancing (nonchewing) than the working (chewing) side of the head, when compared to related species with fused symphyses. Here, we compare jaw adductor recruitment levels in two species of musteloid carnivoran: the carnivorous ferret (unfused symphysis), and the frugivorous kinkajou (fused symphysis). During forceful chewing, we observe that ferrets recruit far more working-side muscle force than kinkajous, regardless of food toughness and that high working-to-balancing side ratios are the result of increased working-side force, often coupled with reduced balancing-side force. We propose that in carnivorans, high working-to-balancing side force ratios coupled with an unfused mandibular symphysis are necessary to rotate the hemimandible for precise unilateral occlusion of the carnassial teeth and to sustain laterally oriented force on the jaw to engage the carnassial teeth during shearing of tough foods. In contrast, the kinkajou's flattened cheekteeth permit less precise occlusion and require medially-oriented forces for grinding, thus, a fused symphysis is mechanically beneficial.

Correction: 'The welfare problems of wide-ranging Carnivora reflect naturally itinerant lifestyles' (2023), by Bandeli et al.

[This corrects the article DOI: 10.1098/rsos.230437.][This corrects the article DOI: 10.1098/rsos.230437.].

Fast Bayesian inference of phylogenies from multiple continuous characters.

Time-scaled phylogenetic trees are an ultimate goal of evolutionary biology and a necessary ingredient in comparative studies. The accumulation of genomic data has resolved the tree of life to a great extent, yet timing evolutionary events remains challenging if not impossible without external information such as fossil ages and morphological characters. Methods for incorporating morphology in tree estimation have lagged behind their molecular counterparts, especially in the case of continuous characters. Despite recent advances, such tools are still direly needed as we approach the limits of what molecules can teach us. Here, we implement a suite of state-of-the-art methods for leveraging continuous morphology in phylogenetics, and by conducting extensive simulation studies we thoroughly validate and explore our methods' properties. While retaining model generality and scalability, we make it possible to estimate absolute and relative divergence times from multiple continuous characters while accounting for uncertainty. We compile and analyze one of the most data-type diverse data sets to date, comprised of contemporaneous and ancient molecular sequences, and discrete and continuous characters from living and extinct Carnivora taxa. We conclude by synthesizing lessons about our method's behavior, and suggest future research venues.

Evolutionary ecomorphology for the twenty-first century: examples from mammalian carnivores.

Carnivores (cats, dogs and kin) are a diverse group of mammals that inhabit a remarkable range of ecological niches. While the relationship between ecology and morphology has long been of interest in carnivorans, the application of quantitative techniques has resulted in a recent explosion of work in the field. Therefore, they provide a case study of how quantitative techniques, such as geometric morphometrics (GMM), have impacted our ability to tease apart complex ecological signals from skeletal anatomy, and the implications for our understanding of the relationships between form, function and ecological specialization. This review provides a synthesis of current research on carnivoran ecomorphology, with the goal of illustrating the complex interaction between ecology and morphology in the skeleton. We explore the ecomorphological diversity across major carnivoran lineages and anatomical systems. We examine cranial elements (skull, sensory systems) and postcranial elements (limbs, vertebral column) to reveal mosaic patterns of adaptation related to feeding and hunting strategies, locomotion and habitat preference. We highlight the crucial role that new approaches have played in advancing our understanding of carnivoran ecomorphology, while addressing challenges that remain in the field, such as ecological classifications, form-function relationships and multi-element analysis, offering new avenues for future research.

Molecular-phylogenetic analyses of Ixodes species from South Africa suggest an African origin of bird-associated exophilic ticks (subgenus Trichotoixodes).

BACKGROUND: Among hard ticks (Acari: Ixodidae), the genus Ixodes comprises the highest number of species, which in turn are most numerous in the Afrotropical zoogeographic region. In South Africa extensive morphological studies have been performed on Ixodes species but only few reports included molecular analyses. METHODS: In this study, 58 Ixodes spp. ticks, collected from ten mammalian and eight avian host species in South Africa, were molecularly and phylogenetically analyzed. In addition, a newly collected sample of the Palearctic Ixodes trianguliceps was included in the analyses. RESULTS: Among the ticks from South Africa, 11 species were identified morphologically. The majority of ticks from mammals represented the Ixodes pilosus group with two species (n = 20), followed by ticks resembling Ixodes rubicundus (n = 18) and Ixodes alluaudi (n = 3). In addition, single specimens of Ixodes rhabdomysae, Ixodes ugandanus, Ixodes nairobiensis and Ixodes simplex were also found. Considering bird-infesting ticks, Ixodes theilerae (n = 7), Ixodes uriae (n = 4) and ticks most similar to Ixodes daveyi (provisionally named I. cf. daveyi, n = 2) were identified. Molecular analyses confirmed two species in the I. pilosus group and a new species (I. cf. rubicundus) closely related to I. rubicundus sensu stricto. Phylogenetic trees based on concatenated mitochondrial or mitochondrial and nuclear gene sequences indicated that the subgenus Afrixodes forms a monophyletic clade with bird-associated exophilic ticks (subgenus Trichotoixodes). Ixodes trianguliceps clustered separately whereas I. alluaudi with their morphologically assigned subgenus, Exopalpiger. CONCLUSIONS: Phylogenetic analyses shed new lights on the relationships of Ixodes subgenera when including multiple sequences from subgenus Afrixodes and African as well as Palearctic species of subgenera Trichotoixodes and Exopalpiger. Subgenera Afrixodes and bird-associated Trichotoixodes share common ancestry, suggesting that the latter might have also originated in Africa. Regarding the subgenus Exopalpiger, I. alluaudi is properly assigned as it clusters among different Australian Ixodes, whereas I. trianguliceps should be excluded.

High-throughput DNA metabarcoding for determining the gut microbiome of captive critically endangered Malayan tiger (Pantheratigrisjacksoni) during fasting.

The Malayan tiger (Pantheratigrisjacksoni) is a critically endangered species native to the Malaysian Peninsula. To imitate wild conditions where tigers do not hunt every day, numerous wildlife sanctuaries do not feed their tigers daily. However, the effects of fasting on the gut microbiota of captive Malayan tigers remains unknown. This study aimed to characterise the gut microbiota of captive Malayan tigers by comparing their microbial communities during fasting versus normal feeding conditions. This study was conducted at the Melaka Zoo, Malaysian Peninsula and involved Malayan tigers fasted every Monday. In total, ten faecal samples of Malayan tiger, two of Bengal tiger (outgroup) and four of lion (outgroup) were collected and analysed for metabarcoding targeting the 16S rRNA V3-V4 region. In total, we determined 14 phyla, 87 families, 167 genera and 53 species of gut microbiome across Malayan tiger samples. The potentially harmful bacterial genera found in this study included Fusobacterium, Bacteroides, Clostridium sensu stricto 1, Solobacterium, Echerichiashigella, Ignatzschineria and Negativibacillus. The microbiome in the fasting phase had a higher composition and was more diverse than in the feeding phase. The present findings indicate a balanced ratio in the dominant phyla, reflecting a resetting of the imbalanced gut microbiota due to fasting. These findings can help authorities in how to best maintain and improve the husbandry and health of Malayan tigers in captivity and be used for monitoring in ex-situ veterinary care unit.

The welfare problems of wide-ranging Carnivora reflect naturally itinerant lifestyles.

Carnivora with naturally small home ranges readily adjust to the evolutionarily new environment of captivity, but wider-ranging species seem prone to stress. Understanding why would advance both collection planning and enclosure design. We therefore investigated which aspects of wide-ranging lifestyles are key. We identified eight correlates of home range size (reflecting energetic needs, movement, intra-specific interactions, and itinerant lifestyles). We systematically assessed whether these correlates predict welfare better than range size per se, using data on captive juvenile mortality (from 13 518 individuals across 42 species) and stereotypic route-tracing (456 individuals, 27 species). Naturally itinerant lifestyles (quantified via ratios of daily to annual travel distances) were found to confer risk, predicting greater captive juvenile losses and stereotypic time-budgets. This finding advances our understanding of the evolutionary basis for welfare problems in captive Carnivora, helping explain why naturally sedentary species (e.g. American mink) may breed even in intensive farm conditions, while others (e.g. polar bears, giant pandas) can struggle even in modern zoos and conservation breeding centres. Naturally itinerant lifestyles involve decision-making, and strategic shifts between locations, suggesting that supplying more novelty, cognitive challenge and/or opportunities for control will be effective ways to meet these animals' welfare needs in captivity.