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Steroid-hormone concentrations from non-invasively obtained biomarkers, like hair, can provide a representation of circulating hormones diffused over relatively long time periods (e.g., weeks or months). The hormone cortisol is often associated with physiological or even psychological stress, while testosterone is strongly associated with male development and reproductive success. Increasingly, studies are using hormone levels derived from hair to make inferences among both domestic animals and wildlife. For horses, all previous hair hormone analysis has been done on companion or working animals. We evaluated the levels of hair cortisol (n = 153) and testosterone (n = 48) from 136 feral horses living on Sable Island, Canada that have been part of a long-term individual-based study since 2008. This population has been undisturbed and unmanaged for over 50 years, and exhibits the natural social organization for horses, harem defense polygyny. Hair samples were collected in mid to late summer and the segment analyzed corresponds with hair grown during, and following, the peak of the reproductive season. Social position was determined based on the male’s role as either a dominant breeding Stallion (Stallion), a non-breeding subordinate male (tag), adult Bachelor (5 years old or older), or Immature male (2–4 years of age). While there was no difference in hair-cortisol concentration among any class of adult males (i.e., Stallion, tag, or Bachelor), Immature males had significantly lower hair cortisol concentrations than the other groups (p = 0.001). Hair testosterone levels among the four social positions were significantly higher among Stallions (p = 0.04). Hair testosterone concentration was also significantly related to the probability of a male being either a Bachelor or Stallion and was the only variable remaining in AICc model selection (p = 0.016, AICc = 32.3, Null AICc = 38.8). While not a significant relationship, Stallions had a negative correlation between hair cortisol concentrations and testosterone (R2 = −0.20, p = 0.383), and Bachelors, conversely, had a positive association (R2 = 0.43, p = 0.246). Our observations of hormone concentrations in relation to physiological, social, or reproductive parameters in this population suggest trends that are similar to what has been established using blood or other matrices.

Cortisol is a glucocorticoid hormone produced during activation of the hypothalamic–pituitary–adrenal axis (HPA) in response to psychological or physiological demands. High amounts of circulating cortisol can be found in individuals experiencing energetically demanding physiological events, such as pregnancy, lactation, injury, or starvation, but, also, in individuals who may have less obvious HPA activation from social situations. The feral horse population on Sable Island (Nova Scotia, Canada) provides an opportunity to look at hair cortisol concentration (HCC) as a proxy for circulating cortisol concentration to better understand physiological correlates. The horse’s complex social structure also allows us to look at how the population and group structure may influence HPA activation. Hair samples (n = 282) were analyzed from 113 females and 135 males. Females with dependent offspring (foals) had higher HCC than those females without dependent offspring (p = 0.005). Horses in poor body condition were also more likely to have higher HCC (females: p < 0.001, males: p = 0.028); females had greater variation in the body condition index (BCI), which also correlated with foal production. In general, the top-ranked models describing female cortisol levels included age, BCI, presence of a foal, as well as social measures such as harem size and the number of bachelors in the vicinity. The top model describing male cortisol levels included age, BCI, and year of collection only, and the number of bachelors in the home range appeared in subsequent, though still high-ranked, models. Among the variables not of direct interest, we found some significant results relating to hair color and hair texture. Differences in HCC patterns between feral and domestically kept horses (e.g., age and sex) are likely linked to periods of resource limitations, particularly for individuals experiencing energetically demanding processes such as reproduction, illness/parasitism, or related to experiencing the full range of social and reproductive behaviors.

In this study, we examined the ventral process of C6 in extinct and extant Equus (sister taxa to Equus ferus caballus only) with the purpose of describing normal morphology and identifying anomalous variations relevant to recent studies describing a congenital malformation in E. ferus caballus. Overall, 83 specimens from 9 museums and 3 research/educational facilities were examined, totalling 71 extinct specimens from 12 species and 12 extant specimens from 5 species. The lateral view revealed that a large convexity exists in the ventral process between the cranial ventral tubercle (CrVT) and the caudal ventral tubercle (CVT) in the earliest ancestor, Hyracotherium grangeri, from 55 mya, which receded throughout the millennia to become a smaller convexity in E. ferus caballus and the sister taxa. The CrVT is visibly shorter and narrower than the CVT, with a constricted section directly ventral to the transverse process, essentially demarcating the CrVT and CVT. No congenital malformations were evident. As the ventral process of C6 is an integral component for muscle attachment in supporting the head/neck during posture and locomotion, this would indicate that the caudal module in the cervical column might be compromised when a partial or complete absence of the CVT is detected via radiographs in modern E. ferus caballus.

The aim of this study was to investigate equine piroplasms of wild horses (Equus ferus caballus) in Konya province of Turkey in November-December 2017. For this aim, blood samples were collected from 36 wild horses and examined for equine piroplasms by microscopy and multiplex PCR. Some of the PCR products from positive samples were also sequenced. Five (13.89%) out of the 36 horses were infected with either Theileria equi, Babesia caballi or both in the microscopical examination. Single infections with T. equi and B. caballi were detected in three (8.33%) and one horses (2.78%), respectively. Prevalence of T. equi, B. caballi and mix infections was determined as 50%, 38.8% and 38.8% by multiplex PCR, respectively. Multiplex PCR was found more sensitive than microscopical examination to detect the piroplasms of horses. The results of sequence analysis showed 99.25-100% and 98.23-99.59% nucleotide sequence identity to the previously reported T. equi and B. caballi 18S rRNA gene sequences, respectively. Consequently, the existence of equine piroplasmosis in wild horses was reported for the first time in Turkey, and high molecular prevalences of T. equi and B. caballi were reported with this study.

Free-roaming horses (Equus ferus caballus) occur throughout arid and semiarid regions of the western United States, where they can decrease plant biomass and diversity, impair water quality, and reduce forage available to native wildlife and domestic livestock. Management of free-roaming horses on Bureau of Land Management (BLM) and US Forest Service lands is determined by protections and population targets established by law, but these do not apply to other federal or Tribal Lands, where relatively little is known about the abundance and distribution of free-roaming horses. To address this information gap, we conducted the first comprehensive survey of free-roaming horses within the Navajo Nation, which is the largest Tribal Land holding in the contiguous United States and covers portions of the states of Arizona, New Mexico, and Utah. We used stratified random sampling and double-observer distance methods to produce estimates of horse abundance corrected for detection bias. During the summer of 2016, we used fixed-wing aircraft to survey 4 975 km of transects across our 67 089-km2 study area. We observed 4 290 horses distributed among 527 groups and estimated 38 223 horses lived within the study area during the survey period (standard of error [SE]: 6 052, 90% confidence interval: 29 365–47 080), with 29 394 horses in open areas (SE: 5 511, 90% confidence interval [CI]: 21 328–37 460) and 8 829 horses in forested areas (SE: 2 331, 90% CI: 5 417–12 240). Overall density of 0.570 horses/km2 (SE: 0.090, 90% CI: 0.438–0.702) was 23% higher than density of horses and burros (Equus asinus) in all BLM herd management areas (HMAs) in 2016 and exceeded by 17% the density in Nevada, the only state with an HMA of comparable size to the Navajo Nation. Our results will inform management of a free-roaming horse population that this study has revealed to be the among the largest in the United States.

The endometrium, the inner uterine lining, is composed of cell layers that come in direct contact with an embryo during early pregnancy and later with the fetal placenta. The endometrium is responsible for signals associated with normal reproductive cyclicity as well as maintenance of pregnancy. In the mare, functionally competent in vitro models of the endometrium have not been successful. Furthermore, the ability to study various reproductive processes in vitro may allow critical evaluation of signaling pathways involved in the reproductive diseases of animals that cannot be handled frequently, such as various wildlife species. Here we report the establishment of organoids, 3D structures, derived from fresh and frozen–thawed equine endometrium (Equus ferus caballus and E. f. przewalskii). Although organoids from domestic mares responded to exogenous hormonal stimuli, organoids from Przewalski’s horse failed to respond to exogenous hormones. The present study represents a ‘first’ for any large animal model or endangered species. These physiologically functional organoids may facilitate improved understanding of normal reproductive mechanisms, uterine pathologies, and signaling mechanisms between the conceptus and endometrium and may lead to the development of novel bioassays for drug discovery.

Caribou (Rangifer tarandus) populations are sympatric with Cougars (Puma concolor) in only a few areas, primarily in western Canada. Records of Cougar–Caribou interactions are limited and no published accounts describe Cougar predation on the shallow-snow, terrestrial-lichen-eating Northern Mountain Caribou (Rangifer tarandus caribou), referred to as Designatable Unit (DU) 7 by the Committee on the Status of Endangered Wildlife in Canada. In 2018 and 2019, two incidents of confirmed Cougar predation on radio-collared Caribou were documented in the declining Itcha-Ilgachuz subpopulation in west-central British Columbia. To the best of our knowledge, this is the first published record of Cougar predation on DU7 Northern Mountain Caribou. Increased landscape disturbance and climate change may be increasing apparent competition between deer (Odocoileus spp.), feral Horses (Equus ferus caballus), and Caribou, leading to Cougar predation in areas of Caribou range where it previously has not been documented. Cougar predation may become a conservation concern, as declining Caribou herds are susceptible to any increased predation pressure.

This work aimed to investigate the prevalence of Trichinella infection in horses (Equus ferus caballus) handled by rural slaughterhouses across five distinctive socioeconomic regions in Mexico. Serum samples were obtained by non-probabilistic convenience sampling in the Eastern, Southern Central and Western regions (100 samples of each). Additionally, muscle tissue samples were collected from the East (n=45), Southeastern (n=88), Southern Central (n=39) and Southwestern (n=11) regions. Antibodies were determined by Western blot and the muscle tissue was examined by artificial digestion. A global antibody prevalence of 2% was obtained. Regionally, a prevalence of 5% was observed in the East and 1% in the Southern Central region. No antibodies were detected in the West region and no larvae were found in the muscle tissue samples. These findings support the low presence of Trichinella in Mexican horses, which can positively impact the Mexican horse meat trade.

Horses (Equus ferus caballus) have evolved over the past 300 years in response to man-made selection for particular athletic traits. Some of the selected traits were selected based on the size and horses' muscular power (eg Clydesdales), whereas other breeds were bred for peak running performance (eg Thoroughbred and Arabian). Although the physiological changes and some of the cellular adaptations responsible for athletic potential of horses have been identified, the molecular mechanisms are only just beginning to be comprehensively investigated. The purpose of this review was to outline and discuss the current understanding of the molecular mechanisms underpinning the athletic performance and cardiorespiratory fitness in athletic breeds of horses. A brief review of the biology of epigenetics is provided, including discussion on DNA methylation, histone modifications and small RNAs, followed by a summary and critical review of the current work on the exercise-induced epigenetic and transcriptional changes in horses. Important unanswered questions and currently unexplored areas that deserve attention are highlighted. Finally, a rationale for the analysis of epigenetic modifications in the context with exercise-related traits and ailments associated with athletic breeds of horses is outlined in order to help guide future research.

Approximately 250 feral horses [Equus ferus caballus (Linnaeus, 1758)] living on Karadag Mountain near Karaman City were caught by Kazakh horse herdsmen with permission of the Turkish Ministry of Agriculture and Forestry and brought to a farm in Karkin village in Konya Province, 70 km from Karadag, in November, 2017. This study was carried out to determine the presence of ectoparasites infesting a subsample of 36 feral horses. The horses were visually inspected, and then their bodies were checked by hand for ectoparasites. Thirty-five (97.2%) were infested with at least one of five species of ectoparasites: Bovicola equi (Linnaeus, 1758), Hippobosca equina (Linnaeus, 1758), Haemaphysalis parva (Neuman, 1897), Hyalomma excavatum (Koch, 18449), Dermacentor marginatus (Sulzer, 1776). Most of the horses were coinfested with two ectoparasite species. Prevalence of infestation with H. equina was 80.6% and with B. equi 72.2%. In addition, prevalence of Ha. parva was 25.0%, Hy. excavatum 13.9%, and D. marginatus was 5.6%. This is the first systematic examination for external parasites of feral horses in Turkey. Further studies are needed to determine ectoparasites of greater numbers of feral horses in different localities.

The complete mitochondrial genome of Eimeria leuckarti (Eimeriidae, Coccidia, Apicomplexa) was obtained. This morphologically distinctive coccidium is considered to be the only valid Eimeria species of equids and it infects a range of both domestic and wild horses and their relatives. Despite the distinctive appearance of the oocysts of E. leuckarti, the mitochondrial genome organization and gene contents were comparable to other Eimeria spp. and related eimeriid coccidia infecting a range of mammals and birds. The greatly reduced 6242 bp genome is circular-mapping and contains three protein-coding genes (COI, COIII, CytB), 18 fragments encoding the large subunit rRNA (LSU), and 13 fragments encoding the small subunit (SSU) rRNA. No tRNA was encoded similar to other Apicomplexa. A Bayesian inference tree based on aligned CDS and rDNA fragments from Eimeria leuckarti and 34 other coccidia demonstrated that this mt genome has close phylogenetic affinities to Eimeria and Isospora species, and related eimeriid coccidia.

Water is a requirement for all organisms, including equids. Dehydration-caused mortality of feral horses (Equus ferus caballus) is often cited as a cause of concern and as justification for management of feral horses, yet a paucity of information exists on the matter. We conducted a systematic review from September 1, 2020 through January 15, 2021 of available news reports of feral horse and burro (E. asinus) dehydration mortalities and public interventions to save horses using a public search engine with a priori defined search term combinations and additional snowball sampling. We found 15 uniquely reported mortality incidents representing 744 horse in the United States and Australia that occurred between 1976 and 2019; no similar reports for burros were found. Mortalities occurred during hotter and drier than normal conditions with occurrences escalating through the summer and fall. The number of horses per dehydration mortality event ranged from 1–191 with a mean of 50 horses. Mortalities occurred on a wide range of land jurisdictions including private lands, tribal lands, national forests, national parks, and Bureau of Land Management lands. Increasing feral horse populations in western North America and Australia, coupled with the drought forecasts over the next century, simply cannot be ignored. This study represents the first global and longitudinal assessment of feral horse dehydration mortalities.

H παρακολούθηση του πληθυσμού των ειδών της άγριας πανίδας αποτελεί θεμελιώδες εργαλείο στη διαχείρισή τους, και χρησιμοποιείται για την αναγνώριση των περιβαλλοντικών συνθηκών, οι οποίες συνδέονται άμεσα με τη χρήση και την επιλογή του ενδιαιτήματος τους. Η μοντελοποίηση της καταλληλότητας του ενδιαιτήματος (ΜΚΕ) (Habitat Suitability Modeling, HSM) ενός είδους, συνδυάζοντας τα γεωγραφικά συστήματα πληροφοριών (GIS) και τις στατιστικές μεθόδους, εφαρμόζεται με σκοπό την παροχή πληροφορίας για τη χρήση και αξιοποίηση του ενδιαιτήματος από το είδος. Σε αυτή την εργασία, μελετήθηκαν τα άγρια άλογα (Equus ferus caballus L.) του όρους Μενοικίου, στο νομό Δράμας, το οποίο εντάσσεται στο δίκτυο προστατευόμενων περιοχών του δικτύου «NATURA 2000». Ερευνήθηκε η χρήση του χώρου από τον πληθυσμό των αλόγων, αξιοποιώντας αβιοτικές παραμέτρους (υψόμετρο, κλίση, έκθεση, υδρογραφικό δίκτυο, δρόμοι, χρήσεις γης) και το βιοτικό περιβάλλον (φυτοκάλυψη, αλληλεπιδράσεις με άλλα είδη), με τελική παραγωγή χαρτών, αναπαριστώντας κατά ένα πιθανολογικό πρότυπο την καταλληλότητα για χρήση του ενδιαιτήματος από το άγρια άλογα. Η καταλληλότητα του ενδιαιτήματος κατηγοριοποιήθηκε σε τέσσερα επίπεδα: πλήρως κατάλληλο, κατάλληλο, αποδεκτό και ακατάλληλο ενδιαίτημα, ανάλογα με τα στοιχεία του πεδίου. Σύμφωνα με τα επίπεδα αυτά, διαμορφώθηκε και ο τελικός χάρτης των καταλληλότερων ενδιαιτημάτων για τα άγρια άλογα στο όρος Μενοίκιο., The monitoring of the population of wild fauna species is a fundamental tool in their management, and is used to identify the environmental conditions, which are directly related to the use and selection of their habitat. Habitat Suitability Modeling (HSM) of a species is applied to provide information on the use and utilization of the habitat by the species, combining Geographic Information Systems (GIS) and statistical methods. In this study, the target species was the wild horse (Equus ferus caballus L.) of Mount Menikio, in the prefecture of Drama, which is part of the network of protected areas of the "NATURA 2000".The use of space by the horse population was investigated, utilizing abiotic parameters (altitude, slope, exposure, hydrographic network, roads, land uses) and the living environment (vegetation, interactions with other species), with a final map production, representing a probabilistic model the suitability for habitat use by wild horses. Habitat suitability was categorized into four levels: highly suitable, suitable, acceptable, and unsuitable habitat, depending on field data. According to these levels, the final map of the most suitable habitats for wild horses on Mount Menikio was formed.

Many wild horse (Equus ferus caballus) populations that inhabit designated federal land in the United States currently exceed management objectives. Overabundant wild horse populations can adversely impact the ecosystem, native wildlife, and other land uses. Unfortunately, there is not a universal solution, as each impacted area may differ ecologically, economically, socially, and politically. Wild horse management is not just a 1-time project but a long-term program where buy-in is needed from the federal and state agencies, local governments, and private partners. Local county governments and private partners can have important insights and significant influence on the development and success of local wild horse management strategies. The combined involvement of local government and stakeholders can have a wide range of benefits including increasing capacity for management, developing new management and placement techniques, and creating authentic program branding and outreach for better placement success. Partners can often complete projects in tighter time frames, find employees, and experience less government red tape in implementation. Buy-in from the local community can also decrease the amount of negative feedback during management implementation and create a support network to counteract the negative aspects of management. Located in the northeast corner of the state of California, USA, Modoc County recognized early on the need for local government participation in conversations and decisions surrounding wild horses and their management on the Devil’s Garden Plateau Wild Horse Territory (WHT). The county implemented a coordinated planning and government-to-government communication process starting in 2011 to engage the Modoc National Forest, which manages the WHT, in meaningful solution-based dialogue. This paper offers examples of unique collaborative opportunities and solutions that have been successfully used in Modoc County to develop and implement a wild horse management plan. In the years since it was adopted, this plan has halted population growth and started to return the population to the appropriate management level on the Devil’s Garden Plateau.

The Wild Free-Roaming Horses and Burros Act of 1971 provides federal oversight and protection for feral horses (wild free-roaming; WFR horses) that inhabit designated areas on public lands in the western United States. The Bureau of Land Management (BLM) estimated in 2019 that over 80,000 free-roaming equids inhabited 29 million hectares on 177 designated herd management areas. This population estimate exceeds the designated appropriate management level of 26,785. To provide BLM managers with insights regarding the U.S. public knowledge and perceptions about the management of WFR horses in the U.S., we surveyed the public using an online survey process. We hypothesized that respondents from the western U.S. would be more knowledgeable of the ecology and management of WFR horses, because of their proximity to most of the WFR horses managed in the U.S. We stratified the U.S. into five regions, with the intent to acquire at least 400 responses from each; we met this quota in four of the five regions (n of southwest = 376). Overall, the U.S. public was unknowledgeable about the ecology of WFR horses and legal management options to control their populations. While there were some associations between region, sex, age, income, and each of our questions, the strength of these associations was very weak. Therefore, demographics may not be useful in predicting the level of knowledge of the U.S. public concerning WFR horses. Our results highlight the need for improved outreach and communication efforts regarding the issues and consequences of free-roaming equid management approaches.

The objective of this work was to determine how different types of gait affect the physiological and thermographic responses of Pantaneiro horses (Equus ferus caballus) subjected to field conditions under high environmental temperatures. Ten horses were evaluated in a double 5x5 Latin square experimental design, with five gait types: walk, trot, extended trot, gallop, and extended gallop. The following physiological measures were determined immediately after exercise: heart and respiratory rates, blood lactate content, and rectal temperature. Body surface temperatures were evaluated using an infrared camera. The walk, trot, and extended trot were the most adequate gaits for Pantaneiro horses to maintain thermoregulation within the physiological norms under conditions with a high air temperature. The temperatures obtained in the eye and elbow regions show the best predictive capacity for physiological parameters. Resumo O objetivo deste trabalho foi determinar como os diferentes tipos de andamento afetam as respostas fisiológicas e termográficas de cavalos Pantaneiro (Equus ferus caballus) submetidos a condições ambientais com alta temperatura. Dez cavalos foram avaliados em delineamento experimental de quadrado latino 5x5 duplo, com cinco andamentos: passo, trote, trote estendido, galope e galope estendido. As seguintes medidas fisiológicas foram determinadas logo após os exercícios: taxas cardíaca e respiratória, teor de lactato sanguíneo e temperatura retal. As imagens termográficas foram avaliadas por meio de câmera de infravermelho. O passo, o trote e o trote estendido foram os andamentos mais adequados para os cavalos Pantaneiros manterem a termorregulação dentro das normas fisiológicas em condições de alta temperatura do ar. As temperaturas obtidas nas regiões da área do olho e da axila mostram maior capacidade preditiva para os parâmetros fisiológicos.

SUMMARY: As a result of their intense physical activity, racehorses suffer high tendon stress which may result in various pathologies. One of these is tendonitis in the tendon of the superficial digital flexor muscle (TSDFM). Conventional treatment with rest, has not shown to be very effective, and regenerative medicine through the application mesenchymal stem cells appears to be a promising therapy. The objective of this work was to assess the effect of the application of autologous MSC on reduction of the scar length in recurrent TSDFM tendinitis in Holsteiner horses, using image analysis. This study included two groups of five animals each: A control group that received conventional treatment (CG) and an experimental group which was also treated with intralesional injections of MSC (EG). Scar evolution was assessed by echographic analysis, with measurements taken of the scar length over a four month period; the length at month zero, was taken as the initial value of 100 %. During the first month, the mean scar length diminished to 81.14 % (EG) and 95.85 % (CG); after the second month, lengths were 64.4 % (EG) and 92.3 % (CG); following the third month lengths were 51.92 % (EG) and 87.42 % (CG); finally at the end of the fourth month the lengths recorded were 26.7 % (EG) and 83.92 % (CG). These results show that treatment with autologous MSC helps TSDFM scar length was significantly reduced, as compared to conventional treatment.

The invasive grass cheatgrass (Bromus tectorum L.) presents major challenges for land management and habitat conservation in the western United States. Feral horses (Equus ferus caballus) have become overabundant in some areas of the West and can impact fragile semiarid ecosystems. Amid ongoing efforts to control cheatgrass in the Great Basin, we conducted a study to determine if feral horses contribute to the spread of cheatgrass through distribution via their feces. We collected feral horse fecal samples from Little Book Cliffs Herd Management Area in western Colorado in 2014. Fecal samples were dried, and 20 from each of 3 collection sessions were cultivated to examine germination success. Six species germinated from 18 samples (30%; mostly one plant per sample where germination occurred), including cheatgrass from 8% of samples. In a separate study we examined the diet of this same horse population using fecal plant DNA barcoding. Plant species that germinated were rare in the diet and germinated from fewer samples than expected relative to their detection in the diet. Our results suggest that feral horses could be contributing to cheatgrass propagation. Native ungulates and domestic cattle also have this potential. Although management of all large ungulates is necessary to mitigate cheatgrass spread, control of feral horse numbers is particularly necessary.

In the rapidly expanding field of comparative thanatology, reports from a wide range of taxa suggest that some aspects of a concept of death may be shared by many non-human species. In horses, there are only a few anecdotal reports on behaviors toward dead conspecifics, mostly concerning domestic individuals. Here, we describe the case of a 2-month-old, free-ranging male foal that died around 12 h after being found severely injured due to a presumed wolf attack, focusing on other individuals' reactions to the dying foal. We also placed camera traps near horse carcasses to investigate reactions by other horses. Kin and non-kin of both sexes showed unusual interest in the dying foal. However, horses appeared to avoid dead conspecifics. Recording individual reactions to dead and dying conspecifics in naturalistic settings will enhance our knowledge about death-related behaviors in horses, allowing comparisons with other species that have been more thoroughly studied, to understand the evolutionary basis of these behaviors.

In this paper we analyse the taphonomic signatures of captive jaguars (Panthera onca) in order to explore the potential of experimental frameworks to distinguish between different felid agents in carnivore-altered palaeontological and archaeological bone assemblages. Many papers have considered carnivore ecology and the bone altering behaviour of different animals since the development of taphonomic research since the 1980's, as part of the hunter vs scavenging debate to understand early hominin sites. Hyenas have been the most studied carnivore, followed by felids and lastly canids. Within felids, lions and leopards have been the focus of most research, whereas other agents, such as jaguars or tigers are still relatively uncharacterised taphonomically. Here we present the results of an experimental feeding program to assess the nature and extent of alterations that captive jaguars can produce on horse (Equus ferus caballus) appendicular bones. Working with captive animals has some limitations, namely the generally greater extent of alterations on captive-analysed assemblages in relation to their wild counterparts. Despite this issue, we aim to start developing a broader referential framework of felid ethology that includes jaguars, a relevant taphonomic agent for understanding bone assemblages of the European and American Pleistocene. Therefore, in this preliminary study on the taphonomy of jaguars, we aim to show their prowess as bone-altering agent, capable of generating tooth-marks on long limb bone diaphyses and epiphyseal deletion. The taphonomic behaviour of jaguars has not been documented experimentally in any detail so far.

Ecological and social factors underpinning the inequality of male mating success in animal societies can be related to sex ratio, sexual conflict between breeders, effects of nonbreeders, resource dispersion, climatic conditions, and the various sequential stages of mating competition that constitute the sexual selection process. Here, we conducted an individual‐based study to investigate how local resource availability and demography interact with annual climate conditions to determine the degree of male mating inequality, and thus opportunity for sexual selection across two sequential reproductive episodes (harem and subsequent mate acquisition) in a naturally regulated (feral) horse population in Sable Island National Park Preserve, Canada. Using a 5‐year, spatially explicit, mark‐resight dataset and hierarchical mixed‐effects linear modeling, we evaluated the influence of adult sex ratio (ASR) on mating success and then tested for effects of freshwater availability, density, unpaired male abundance, and precipitation during each breeding season. Unpaired male abundance, freshwater availability, and ASR differed in their effects on male mating success according to year and selection episode. Opportunity for sexual selection in males associated with harem acquisition increased with ASR, and unpaired male abundance further explained weather‐related interannual variation after accounting for ASR. In contrast, once a harem was secured, ASR had little effect on male mating inequality in regard to acquiring additional females, while interannual variation in mating inequality increased with decreasing freshwater availability. Our findings show that local demography, resource availability, and weather effect opportunity for sexual selection in males differently depending on selection episode, and can attenuate or accentuate effects of ASR.

Simple Summary In modern times, horse breeds, mostly in horse racing, are the Thoroughbred varieties obtained by breeding three Godolphin Arabians with British mares in England. Especially in Jeju Island, Korea, Jeju horses have been introduced from Mongolia since the 13th century. They have contributed a lot to the agricultural community, but their population has been rapidly decreasing due to rapid agricultural industrialization. Therefore, we sympathize with Jeju horse-specific genetic variation and compare and analyze evolutionary correlations by utilizing Whole Genome Sequencing analysis to evaluate the genetic diversity of Jeju horses and preserve genetic information. We explored Jeju horse-specific genetic differences through a comparative analysis of large-capacity genomic data between the public database and a Thoroughbred variety. In order to adapt to the barren external environment, it is predicted that Jeju horses have experienced strong positive selection in the direction of accumulating many genetic variations, enough to cause functional differences in the eqCD1a6 gene to have an efficient immune function. In addition, we further validate the Jeju horse-specific single nucleotide polymorphisms in the aqCD1a6 gene by employing the digital PCR method, a diagnostic technique for genetic variations. Abstract The Jeju horse is a native Korean species that has been breeding on Jeju Island since the 13th century. Their shape has a distinct appearance from the representative species, Thoroughbred. Here, we performed a comparison of the Jeju horse and Thoroughbred horse for the identification of genome-wide structure variation by using the next-generation sequencing (NGS) technique. We generated an average of 95.59 Gb of the DNA sequence, resulting in an average of 33.74 X sequence coverage from five Jeju horses. In addition, reads obtained from WGRS data almost covered the horse reference genome (mapped reads 98.4%). Based on our results, we identified 1,244,064 single nucleotide polymorphisms (SNPs), 113,498 genomic insertions, and 114,751 deletions through bioinformatics analysis. Interestingly, the results of the WGRS comparison indicated that the eqCD1a6 gene contains signatures of positive natural selection in Jeju horses. The eqCD1a6 gene is known to be involved in immunity. The eqCD1a6 gene of Jeju horses commonly contained 296 variants (275 SNPs and 21 INDELs) that were compared with its counterpart of two Thoroughbred horses. In addition, we used LOAA, digital PCR, to confirm the possibility of developing a molecular marker for species identification using variant sites. As a result, it was possible to confirm the result of the molecular marker with high accuracy. Nevertheless, eqCD1a6 was shown to be functionally intact. Taken together, we have found significant genomic variation in these two different horse species.

For an adequate management of natural grasslands, the knowledge and understanding of the dietary habits of herbivores and their trophic interactions are fundamental. During two summer seasons, in a mountain range of a sector of the Coquimbo Region, Chile, the botanical composition, diversity, and similarity of the diets of horses, European brown hares, and guanacos were studied, as was the selectivity of the main grassland plant species, using feces microhistology. The contribution of hydromorphic grasses was similar in the diets of guanacos (35.90 ± 7.27%) and horses (32.25 ± 4.50%), differing from that found in hares (16.32 ± 5.32%). Dryland grassland grasses contributed similarly to the diets of horses (13.21 ± 3.22%), guanacos (22.53 ± 5.21%) and hares (18.35 ± 3.81%), as well as graminoids, which averaged 47.79 ± 6.66%, 35.63 ± 10.76% and 38.94 ± 7.88%, in diets of horses, guanacos, and hares, respectively, without significant differences. The contribution of herbaceous dicotyledons was only important in hares (23.76 ± 3.76%), while that of shrubs was low (&lt, 3%) and similar among the three herbivores. Dietary diversity was similar among the three herbivore species (73–79%), with a higher degree of dietary overlap between horses and guanacos (55.7%), which was higher than that obtained between hares and guanacos (50%) and between horses and hares (48%), for which there would be a potential trophic competition between them. The most abundant species of dryland and wet grasslands generally fulfill a functional role of subsistence and a nutritional role of maintenance, however, for the three herbivores studied, a different selective behavior was evidenced, according to their physiological differences, with the selection process little affected by the relative abundance of these species in the grasslands. Due to the above, herbivores resort to the selection of certain species that, despite being not very abundant in grasslands, play an important nutritional and functional role, improving the quality of their diets.

Rangelands are the Earth’s largest land type and provide the feed source for the extensive grazing of beef and dairy cattle (Bos taurus), sheep (Ovis aries), goat (Capra aegagrus hircus), horse (Equus ferus caballus), camel (Camelus spp [...]

Thesis presented at ISPA – Instituto Universitário as to obtain a Master’s degree in the specialty of Cognitive and Behavioural Neuroscience Recent evidence in the animal kingdom, specifically in the Phylum Chordata, has revealed a variety of asymmetries regarding social and non-social behaviours. These preferences for side use can be translated into a lateralized processing of information in the brain. Studies performed with domestic horses show several behavioural asymmetries, however, domestic horses have a lot of interaction with caretakers and tend to lack real threats. This study investigated lateralization in frequency and duration of social interactions (affiliative and agonistic) and in resting behaviours on feral horses (Equus ferus caballus). While a small skewness of the data for a left-side preference was found for agonistic behaviours, statistical analyses revealed no significant bias. Horses were more prone to display grooming interactions using the right side and this behaviour lasted longer on this side, but no bias was found for cross-resting (although a skewness was visible for the left side). As for resting, although no bias was found for frequency of side use, a marginal (albeit non-significant) difference was present for the duration, resting tends to last longer when performed on the left side. These results do not entirely support a right-hemisphere dominance for social interactions nor a valence-specific assumption (left-hemisphere dominance for positive affect and right-hemisphere dominance for negative affect). Our findings on the right-side bias for grooming may eventually be interpreted as a role of the environment (ecological pressures) that shapes lateralization in different behaviours. Novas evidências no Reino Animal, em específico no Filo Chordata, mostram frequências diferentes na direção de comportamentos sociais e não sociais. A propensão pelo uso de um lado revela um processamento de informação lateralizado no encéfalo. Estudos com cavalos domésticos revelam assimetrias comportamentais, porém, cavalos domésticos podem estar sujeitos a treino, para além de uma ausência de perigos como predação. Este estudo investiga a lateralização em cavalos assilvestrados (Equus ferus caballus) na frequência e duração de comportamentos sociais (afiliativos e agonísticos) e no comportamento de repouso. A tendência para o uso do lado esquerdo em comportamentos agonísticos não revelou nenhum enviesamento significativo. Contudo, uma preferência estatisticamente significativa pelo uso do lado direito foi encontrada para o comportamento de grooming e a duração do mesmo era maior com o uso desse lado. O comportamento de repouso cruzado não apresentou diferenças significativas a nível da frequência ou duração, todavia apesar do repouso não ter exibido diferença na frequência, a duração aparenta (apesar de não significativamente) ser mais longa com o uso do lado esquerdo. Estes resultados não apoiam inteiramente a hipótese de um controlo do hemisfério direito para comportamentos sociais nem são inteiramente congruentes com a ideia de especificidade de valência (dominância do hemisfério esquerdo para comportamentos com valência positiva e do hemisfério direito para comportamentos com valência negativa). Contudo, a lateralização para o lado direito no grooming poderá vir a ser interpretada como o resultado de pressões seletivas que moldam a lateralização de diferentes comportamentos.

International audience; Establishing how collective decisions emerge is central to our understanding of animal societies. A frequent approach in collective behaviour studies is to seek for leaders that will trigger and direct group movements. Relatively few studies on collective movements, notably in mammals, took into account the events preceding group departures. Success in recruitment can depend on the arousal state, the behaviour and the spatial distribution of animals before departure. We tested the effect of such factors on recruitment process in two groups of 9 domestic mares, Equus ferus caballus , at pasture. Predeparture periods were compared to control periods to identify their unique characteristics and to understand how they can predict the following collective outcome. We found that predeparture periods were characterized by the simultaneous increase in the number of active and goal-oriented individuals as well as in group cohesion. However, while the temporal patterns of activity and dispersion were unique to predeparture periods, those of orientation were not different from control periods. We also found that before departure individuals started to move towards the future goal area and to position themselves along the front-back axis. Moreover, the front-to-back position of group members was linked to the order in which they joined a collective movement. Finally, the duration of the joining process was positively correlated to the group dispersion. Our findings demonstrate that decision making is a continuous process and emphasize the necessity, in the study of collective decisions, to look beyond the event of initiation itself and the identity of the initiator as recruitment depends on group state before and at departure.

The Palio of Ronciglione has a centuries-old tradition, but what makes it truly unique is the absence of any jockey. When the canape falls, each horse chooses whether to compete with the others, to tag along or simply not to run, depending on different temperaments. In the context of the Palio, the horse represents a co-producer of cultural processes, which also transmits its experience to the younger specimens; this latter aspect is particularly evident in the trajectories chosen during the race, based on an indisputable non-human subjectivity. A first ‘internal’ form of inscription to the species should be noted: racehorses are the result of centuries-old domestication combined with a controlled genetic selection (breeding), which has gradually entangled Equus ferus caballus in human society. A second ‘external’ aspect concerns the racetrack, an environment of inter-species coexistence: created by the human community, it is crossed and experienced by horses, which engrave the urban tissue with their trajectories. The animal’s agency, therefore, emerges through the creative adaptation to the path, an inscription of non-human geometries in this space. The intentionality of the horse is what establishes the performance of the Palio: it may seem paradoxical, but the conservation of this cultural heritage is possible as long as the horse can choose not to run., Il Palio di Ronciglione vanta una tradizione secolare, ma ciò che lo rende davvero unico è l’assenza di qualunque fantino. Alla caduta del canape ogni cavallo sceglie se competere con gli altri, accodarsi o semplicemente non correre, a seconda del carattere di ciascuno. Nel contesto del Palio il cavallo costituisce un co-produttore di processi culturali, che inoltre trasmette la sua esperienza agli esemplari più giovani; quest’ultimo aspetto è particolarmente evidente nelle traiettorie scelte durante la Corsa, fondate su un’incontestabile soggettività non-umana. Va rilevata una prima modalità di iscrizione ‘interna’ alla specie: i cavalli da corsa sono il risultato di una domesticazione secolare abbinata ad una selezione genetica controllata (breeding), che ha progressivamente embricato l’Equus ferus caballus alla società umana. Un secondo aspetto ‘esterno’ riguarda il tracciato della Corsa, vero e proprio ambiente di coesistenza inter-specie: realizzato dalla comunità umana, viene percorso ed esperito dai cavalli, che incidono il tessuto urbano con le loro traiettorie. L’agency dell’animale emerge dunque attraverso l’adattamento creativo al tracciato, un’iscrizione di geometrie non-umane nello spazio. L’intenzionalità del cavallo è ciò che fonda la performance del Palio: per quanto sembri paradossale, la conservazione di questo patrimonio culturale è possibile fintanto che il cavallo può scegliere di non correre.

Study of the morphologic peculiarities of free-living stages of nematodes of the Strongyloides genus is important in differential diagnostics of pathogens. We studied the parasite of goats (Capra aegagrus hircus Linnaeus, 1758) – Strongyloides papillosus (Wedl, 1856); the parasite of horses (Equus ferus caballus Linnaeus, 1758) – S. westeri Ihle, 1917; the parasite of swine (Sus scrofa Linnaeus, 1758 ) – S. ransomi Schwartz & Alicata, 1930; the parasite of dogs (Canis lupus familiaris Linnaeus, 1758) – S. stercoralis (Bavay, 1876). Rhabditiform larvae (L1, L2), filarial larvae (L3), mature males (M) and free-living females (F) were analyzed for each of the four species by five morphological parameters: body length (Lb), total maximum body width (Sb), length of the esophagus (Lo), length of the intestine (Le), length of the tail end (Lc); for females, we additionally examined length from the head end to the vulva (Lv) and the number of formed eggs in the uterus cavity (E), and for males – length of spicules (Ls). First stage larvae of S. papillosus and S. stercoralis significantly differed in all parameters, and first stage larvae of S. westeri and S. stercoralis significantly differed in four out of five parameters. By indices of ratios of total maximum body width (Sb) to body length (Lb), length of the esophagus (Lo) to length of the intestine (Le), length of the tail end (Lc) to body length (Lb), length of the intestine (Le) to body length (Lb), a reliable difference was recorded between L1 of S. papillosus and S. ransomi, L3 of S. papillosus and S. westeri, S. westeri and S. ransomi, between males of S. papillosus and S. westeri, S. westeri and S. stercoralis, between females of S. papillosus and S. westeri, S. papillosus and S. stercoralis. All four examined species were observed to have reliable differences of ratio of length of esophagus to length of intestine in third stage larvae.

From early infancy, humans reason about the external world in terms of identifiable, solid, cohesive objects persisting in space and time. This is one of the most fundamental human skills, which may be part of our innate conception of object properties. Although object permanence has been extensively studied across a variety of taxa, little is known about how non-human animals reason about other object properties. In this study, we therefore tested how domestic horses (Equus ferus caballus) intuitively reason about object properties like solidity and height, to locate hidden food. Horses were allowed to look for a food reward behind two opaque screens, only one of which had either the proper height or inclination to hide food rewards. Our results suggest that horses could not intuitively reason about physical object properties, but rather learned to select the screen with the proper height or inclination from the second set of 5 trials.

Livestock farming was one of the major economic activities during the early Middle Ages. The exploitation of livestock resources became very important since the Visigothic period (C. 415–711 AD), although our knowledge is still considerably limited for the central regions of Iberia. Some historiographical works about stockbreeding during the Middle Ages as well as zooarcheological analyses exist; however, few researchers have focused on the study of farming during the early Middle Ages. We present here a taphonomical and zooarcheological analysis of several archeological sites, in order to illustrate the range of farming strategies developed in the center of the Iberian Peninsula during the VIII–XI centuries (Andalusian period). This study explores the economic exploitation and management strategies of domesticates such as Bos taurus, Ovis aries, Capra hircus, and other, less frequent animals, such as Sus domesticus, Equus ferus caballus, Equus africanus asinus, and Canis familiaris, in addition to wild species. Our results indicate that Ovis/Capra (caprines) were the most represented species at these sites, even though some animals, such as pigs, were more frequent than what we would expect in the Muslim world. Together, these lines of evidence allow us to discuss not only the economics of everyday life in the early Middle Ages, but also the nature of the changes that Iberian populations experienced with the arrival of Christian conquerors.

The absence of preserved soft tissues in the fossil record is frequently a hindrance for palaeontologists wishing to investigate morphological shifts in key skeletal systems, such as the limbs. Understanding the soft tissue composition of modern species can aid in understanding changes in musculoskeletal features through evolution, including those pertaining to locomotion. Establishing anatomical differences in soft tissues utilising an extant phylogenetic bracket can, in turn, assist in interpreting morphological changes in hard tissues and modelling musculoskeletal movements during evolutionary transitions (e.g. digit reduction in perissodactyls). Perissodactyls (horses, rhinoceroses, tapirs and their relatives) are known to have originated with a four-toed (tetradactyl) forelimb condition. Equids proceeded to reduce all but their central digit, resulting in monodactyly, whereas tapirs retained the ancestral tetradactyl state. The modern Malayan tapir (Tapirus indicus) has been shown to exhibit fully functional tetradactyly in its forelimb, more so than any other tapir, and represents an ideal case-study for muscular arrangement and architectural comparison with the highly derived monodactyl Equus. Here, we present the first quantification of muscular architecture of a tetradactyl perissodactyl (T. indicus), and compare it to measurements from modern monodactyl caballine horse (Equus ferus caballus). Each muscle of the tapir forelimb was dissected out from a cadaver and measured for architectural properties: muscle-tendon unit (MTU) length, MTU mass, muscle mass, pennation angle, and resting fibre length. Comparative parameters [physiological cross-sectional area (PCSA), muscle volume, and % muscle mass] were then calculated from the raw measurements. In the shoulder region, the infraspinatus of T. indicus exhibits dual origination sites on either side of the deflected scapular spine. Within ungulates, this condition has only been previously reported in suids. Differences in relative contribution to limb muscle mass between T. indicus and Equus highlight forelimb muscles that affect mobility in the lateral and medial digits (e.g. extensor digitorum lateralis). These muscles were likely reduced in equids during their evolutionary transition from tetradactyl forest-dwellers to monodactyl, open-habitat specialists. Patterns of PCSA across the forelimb were similar between T. indicus and Equus, with the notable exceptions of the biceps brachii and flexor carpi ulnaris, which were much larger in Equus. The differences observed in PCSA between the tapir and horse forelimb muscles highlight muscles that are essential for maintaining stability in the monodactyl limb while moving at high speeds. This quantitative dataset of muscle architecture in a functionally tetradactyl perissodactyl is a pivotal first step towards reconstructing the locomotor capabilities of extinct, four-toed ancestors of modern perissodactyls, and providing further insights into the equid locomotor transition.

Conocer las patologías más frecuentes facilita la orientación clínica mejorando el pronóstico de los pacientes. Para determinar las patologías que se presentan en caballos (Equus ferus caballus) en la Clínica Veterinaria U.D.C.A, se realizó un estudio retrospectivo, entre enero y diciembre de 2017. Se analizaron 242 historias, clasificando los casos, según la fecha, procedencia, raza, sexo, edad, diagnóstico definitivo, sistema, tratamiento médico-quirúrgico y evolución. La procedencia más frecuente fue del departamento de Cundinamarca y de Bogotá; 55,8% fueron hembras, 44,2% machos, con edad entre 1 día y 25 años; 24% jóvenes, 76% adultos, con edad promedio de 81,5 meses y desviación estándar de 51,7 meses; la raza predominante fue Caballo Criollo Colombiano (CCC). Los sistemas más afectados fueron músculo esquelético (SME), digestivo (SD), y reproductivo; los casos más frecuentes fueron Arpeo idiopático o hipertonía equina refleja, que ocurrió únicamente en CCC; alteraciones del intestino grueso, y criptorquidia, respectivamente. Tratamiento quirúrgico, se dio a 66,5% de los casos, principalmente, a los del SME, digestivo y reproductivo. La mortalidad fue de 13,7%; fallecieron 13 equinos y a 22, se les practicó eutanasia; los casos mortales, se presentaron principalmente en los del SD, relacionados con cólico y ninguno en los de los sistemas respiratorio, órganos de los sentidos y tegumentario. La casuística es amplia y variada; el SME fue el más afectado en los caballos. El compromiso funcional y vital para los animales hace necesario investigar sobre factores de riesgo del Arpeo idiopático y cólico equino. Know the most frequent pathologies facilitates the clinical orientation improving the prognosis of the patients. To determine the pathologies that occur in horses at the U.D.C.A Veterinary Clinic, a retrospective study was conducted between january and december 2017. 242 clinical histories were analyzed, classifying the cases according to date, origin, race, sex, age, defi nitive diagnosis, system, medical-surgical treatment and evolution. The most frequent source was the department of Cundinamarca and the city of Bogotá, 55.8% were females, 44.2% males, age between 1 day and 25 years, 24% young, 76% adults with an average age of 81.5 months and a standard deviation of 51.7 months, the predominant breed was Colombian Creole Horse (CCC). The most affected systems were muscle skeletal (ME), digestive (D), and reproductive, the most frequent cases were classic stringhalt or equine refl ex hypertonia, which occurred only in CCC, alterations of the large intestine, and cryptorchidism, respectively. Surgical treatment was given to 66.5% of the cases, mainly to SME, digestive and reproductive cases. Mortality was 13.7%, 13 equines died and 22 were euthanized, fatal cases occurred mainly in those of SD related to colic and none in the respiratory, organs of the senses and integumentary systems. The casuistic is wide and varied, the MES was the most affected in the horses attended, the functional and vital commitment for the animals makes it necessary to investigate the risk factors of the classic stringhalt and equine colic. Incluye referencias bibliográficas

Feral horse (Equus ferus caballus) grazing can alter arid shrubland habitat in the western United States to the detriment of sympatric wildlife species, including the greater sage-grouse (Centrocercus urophasianus). To date, studies of horse-influenced habitat alteration have only occurred in a few locations and have infrequently represented gradients of horse use. We investigated whether greater sage-grouse habitat quality metrics were negatively associated with feral horse use in southcentral Wyoming, USA. We also tested whether utilization distributions generated from feral horses tracked with global position system transmitters were correlated with dung pile density, our index of horse use. Dung pile density did not vary among utilization distribution levels, indicating utilization distributions were a poor predictor of cumulative horse use. Bare ground increased with dung pile density (β = 0.06, 85% CI = 0.04–0.18), and grass height exhibited a threshold response and began to decline after 638 piles/ha. Other habitat metrics including percent shrub cover, native perennial grass cover, and visual obstruction were better explained by topographic and temporal variation. Our results suggest that herd size reduction may limit soil erosion potential and improve desired herbaceous structure, though additional management actions regarding feral horse use are needed to sustain high-quality greater sage-grouse habitat.

Place memory, the ability to remember locations, is a feature of many animal species. This episodic-like memory is displayed in the foraging behavior of animals and has been studied in many different kinds of laboratory spatial tasks. A horse stallion, Equus ferus caballus, will create “dung-heaps or stud-piles” by defecation in the same place suggesting that the behavior is central to spatial behavior but to date there has been little investigation of horse olfactory/spatial behavior. The present study describes investigatory behavior of horses for objects on the surface of a riding arena. Horses under saddle approached objects on the arena surface that included small pieces of straw, fur, and paper and larger objects including clumps of debris and were especially interested in dung droppings left by other horses. Once an object was investigated by sniffing, it was usually not approached again during that outing but could be approached anew on the following day. Dung investigatory behavior and place memory were confirmed in a number of structured tests in which test-retest intervals were varied. The results are discussed in relation to the dual process theory that proposes that spatial representations central to adaptive behavior require both allocentric Cartesian spatial information and egocentric episodic-like information.

Background and Objective: Reactive sulphydryl groups in haemoglobin has been related with oxygen binding. In this study, the researchers analyzed the reactive sulphydryl groups in horse (Equus ferus caballus) carbonmonoxyhaemoglobin. Materials and Methods: Hemolysate gotten from fresh horse blood was converted to yield the carbonmonoxy derivative. It was then separated via carboxymethylcellulose into major and minor fractions of haemoglobin. These fractions were titrated with Ellmanʼs reagent (DTNB) and p-hydroxymercuri(II)benzoate (p-MB) stock solutions in increasing volumes. Results: Results showed that two sulphydryl groups reacted with DTNB and p-MB in both major and minor haemoglobin fractions. p-MB is known to be more reactive with thiols than DTNB, on the other hand the reactivity is the same with horse carbonmonoxyhaemoglobin. Conclusion: This study will enable a better understanding as regards the kinetics and equilibrium behind this reaction.

A human physical asymmetry is the near 90% clockwise occipitoparietal scalp hair-whorl direction in Europeans, an incidence that approximates the left lateralization of speech and right-handedness. Hair-whorl direction is also asymmetric in horses, Equus ferus caballus and placement is proposed to be related to temperament and lateralized skill in equitation manoeuvres. We describe a hair-whorl asymmetry in the horse, mane direction. Of 526, 3-year-old American Quarter horses, 69% of horses had mane directed to the right and 31% had mane directed to the left. The bias was larger in females, with 74% of females vs. 65% of males having mane directed to the right. Mane direction was unrelated to coat colour. The behavioural significance of mane asymmetry was investigated using judges' scores from a reining competition requiring symmetrical maneuvers of spin, circle and roll-back to either the left or to the right. There was no relation between mane asymmetry and overall reining performance and no relation between mane direction and scores for left or right manoeuvres. The results are discussed in relation to the significance of morphological asymmetries, neural function and the influence of planar cell polarity genes, such as Frizzled, that influence epidermal hair cell patterning.

Wild horse (Equus ferus caballus) management in western North America is an escalating concern for ecological integrity on these landscapes. Identifying potential diet overlap among horses, livestock, and wildlife will inform management decisions to optimize multiple interests. To understand dietary relationships, we conducted a quantitative synthesis of microhistological fecal studies for wild horse, beef cattle ( Bos spp.), domestic sheep (Ovis aries), elk (Cervus elaphus), pronghorn (Antilocapra americana), and mule deer (Odocoileus hemionus) diet composition on western rangelands of North America. Our search yielded 60 studies from 14 states, 1 Canadian province, and 2 Mexican states with 392 unique species-season samples. We summarized plant species into graminoid, forb, and browse functional groups. For wild horses, seasonal diet composition means for graminoids (77−89%), forbs (4−15%), and browse (3−10%) did not vary seasonally for any plant group ( P ≤ 0.05). Univariate analyses and the calculation of effect sizes corroborated our finding that graminoid composition explained the potential overlap of wild horses with cattle regardless of season, with sheep and elk in the spring, with sheep in the summer, and with elk in the fall and winter. Although data indicate wild horse diets are primarily composed of graminoids, several studies reported unusual, regionally specific shifts in response to winter snow that limited graminoid accessibility, leading to higher browse composition. Season, plant composition, and ungulate assemblage may all influence dietary competition between wild horses and other large ungulate sharing western North American rangelands; however, the low and nonsignificant heterogeneity values at alpha 0.01 for cattle:horse effect size comparisons suggest that cattle and horses respond to regional and seasonal variation similarly—a result not observed for other ungulate:horse comparisons. Our meta-analysis provides a robust data set for evaluations of diet composition for wild horses, livestock, and wildlife, whereas no empirical studies have assessed all species together.

Parasite infection status, intensity and resistance have traditionally been quantified via flotation techniques, but the need for immediate analysis following defecation imposes limitations and has led to the use of several faecal storage techniques. However, their effect on nematode egg counts has not been systematically validated and is often generalised across taxa despite evidence of differences between species. Here, we take the domestic horse Equus ferus caballus as a model to examine the impact of commonly used storage techniques on egg recovery: 1) high and low concentrations of ethanol and formalin fixative solutions for up to four weeks and 2) refrigeration (3–5°C) over a two-week period. We found a significant decline in faecal egg counts (FEC) following storage in high and low concentrations of both fixative solutions after two weeks, which stabilised after four weeks, and this pattern was uniform across replicates. FECs remained relatively stable over a week of refrigeration, but declined when refrigeration exceeded 8 days. Prior to FEC analysis, we recommend sample refrigeration for no more than one week. Storage in either fixative solution is sub-optimal for the preservation of nematode eggs, although the uniformity of the decline across samples could hold potential for projective calculation of parasite egg shedding when storage time is effectively controlled for.

A new species of lobosean amoeba, Stenamoeba polymorpha n. sp., was isolated from the diarrheic stool of a domesticated horse in Great Falls Virginia, U.S. It shares characteristics with the five other described Stenamoeba species. However, electron microscopy revealed S. polymorpha has a substantially thickened cell surface lamina. Under light microscopy, the amoebae had a dynamic polymorphic appearance because hyaloplasm readily formed and resorbed subpseudopodia from any peripheral region of the cell. While in locomotion, the amoebae produced subpseudopodia that led and alternated the direction of movement with an apparent zigzag path. Sometimes, stationary amoebae had a vertical cell posture that was substantially taller than wide or long. The new species description is also supported by small subunit ribosomal ribonucleic acid gene analyses using phylogenies with both broad and narrow taxon sampling, pairwise nucleotide comparisons, and in-silico secondary structure predictions. The latter suggested Stenamoeba spp. discriminatory motifs in variable region eight. Stenamoeba polymorpha n. sp. is the first of its genus to be recovered from mammal feces, the first to yield a potential group one intron and the second described from North America. Here, the phylogenies suggest Stenamoeba limacina is this new species' nearest known relative.

In New York State (NYS), Eastern equine encephalitis (EEE) was first reported in a human in 1971, in horses in 1970, and in pheasants in 1952.Following work for the interval from 1970 to 1991, we identified cases in vertebrates from 1992 to 2012, through a passive surveillance system involving veterinarians in clinical practice, county health departments, and the Departments of Agriculture and Markets, Environmental Conservation, and Health, of the State of New York.During an 11-year hiatus, from 1992 to 2002, no case in any vertebrate was observed. In a re-emergence, from 2003 to 2012, disease occurred in 12 counties, including 7 counties where disease had never been documented. Vertebrate cases included 4 cases in humans and 77 nonhuman occurrences; in 58 horses, Equus ferus caballus L.; 2 deer, Odocoileus virginianus Zimmermann; 6 dogs, Canis familiaris; 10 birds; and 1 flock of pheasants, Phasianus colchicus L. These were the first reported cases in NYS in white-tailed deer, the domestic dog, and in five species of birds: American crow, Corvus brachyrhynchos Brehm; American goldfinch, Carduelis tristis L.; bald eagle, Haliaeetus leucocephalus L.; blue jay, Cyanocitta cristata (L.); and red-tailed hawk, Buteo jamaicensis Gmelin. One crow was dually infected with EEE virus and West Nile virus. The northern, southern, and southeastern borders of the state were newly affected.The geographic area, time periods, and vertebrate species with risk of EEE disease expanded from 1992 to 2012.

The development of next-generation sequencing technologies has spurred a surge of research on bacterial microbiome diversity and function. But despite the rapid growth of the field, many uncertainties remain regarding the impact of differing methodologies on downstream results. Sample storage temperature is conventionally thought to be among the most important factors for ensuring reproducibility across marker gene studies, but to date much of the research on this topic has focused on short-term storage in the context of clinical applications. Consequently, it has remained unclear if storage at −80 °C, widely viewed as the gold standard for long-term archival of feces, is truly required for maintaining sample integrity in amplicon-based studies. A better understanding of the impacts of long-term storage conditions is important given the substantial cost and limited availability of ultra-low temperature freezers. To this end, we compared bacterial microbiome profiles inferred from 16S V3–V4 amplicon sequencing for paired fecal samples obtained from a feral horse population from Sable Island, Nova Scotia, Canada, stored at either −80 °C or −20 °C for 4 years. We found that storage temperature did not significantly affect alpha diversity measures, including amplicon sequence variant (ASV) richness and evenness, and abundance of rare sequence variants, nor presence/absence, relative abundances and phylogenetic diversity weighted measures of beta diversity. These results indicate that storage of equine feces at −20 °C for periods ranging from a few months to a few years is equivalent to storage at −80 °C for amplicon-based microbiome studies, adding to accumulating evidence indicating that standard domestic freezers are both economical and effective for microbiome research.

Emotional recognition has been demonstrated to occur between members of different species. However, the majority of studies on interspecific communication of emotions so far focused on the senses of vision and hearing while the contribution of the sense of smell has rarely been studied in this context. Thus, the aim of our study was to assess if horses display differential behaviour in response to human fear and non-fear odour. Body odour samples were collected from 10 adult humans (Homo sapiens) in fear and happiness condition, respectively. The human body odour samples collected in these two conditions, together with a control condition, were then presented to a total of 21 horses (Equus ferus caballus). We found that the horses displayed some differential behaviour in response to human fear and non-fear odour. The horses lifted their heads significantly more frequently and for longer in the fear and in the control condition compared to the happiness condition. Similarly, the horses tended to touch a familiar person that was present during the test more frequently and for longer in the fear condition compared to the happiness condition. Additionally, depending on odour condition, the horses differed in the time they spent keeping their ears back. These results can be explained in the context of the process of domestication which may have favoured the development of the ability to recognize heterospecific emotions. To conclude, in the present study we provide evidence for a possible purely olfactory recognition of human emotions by horses.