The study of ecology and horses involves examining the interactions between horses and their environments, including both natural and managed ecosystems. This field explores how horses influence and are influenced by various ecological factors such as vegetation, soil, water sources, and other animal species. Research in this area may address topics such as the grazing behavior of horses, their impact on plant communities, and the role of horses in nutrient cycling within ecosystems. Additionally, studies may investigate the effects of environmental changes and human activities on horse populations and their habitats. This page compiles peer-reviewed research studies and scholarly articles that analyze the ecological roles of horses, their interactions with ecosystems, and the implications for conservation and land management.
Turner JW, Rutberg AT.There are only two nonlethal approaches with which to manage wildlife populations: remove excess individuals or decrease reproductive rates. In the case of wild horse management, the latter has already been shown to be a more humane and less costly approach. Contraception has been known for many years to be effective in wild horses with regard to both fertility and population alteration. Field testing under real-world management situations is a critical aspect of wildlife contraception assessment. Field testing also requires documentation to justify eventual large-scale use of fertility contro...
Sofizadeh A, Telmadarraiy Z, Rahnama A, Gorganli-Davaji A, Hosseini-Chegeni A.A survey on tick species composition was carried out in Golestan Province Iran during year 2010-2011.The aim was to determine tick species parasitizing domestic ruminants and their seasonal population dynamics. Methods: A total of 124 sheep, 92 goats, 84 cattle, 74 camels and 12 horses in several villages were inspected for tick infestation. The collected ticks preserved in 70% alcohol and then were identified. Results: The overall 1059 ticks (453 female, 606 male) were collected. The ticks occur on sheep, goats, cattle, camels and horses as 72.1%, 77.3%, 75.8%, 69.3%, and 50% respectively. Th...
Hendrickson SL.Life at high altitude results in physiological and metabolic challenges that put strong evolutionary pressure on performance due to oxidative stress, UV radiation and other factors dependent on the natural history of the species. To look for genes involved in altitude adaptation in a large herbivore, this study explored genome differentiation between a feral population of Andean horses introduced by the Spanish in the 1500s to the high Andes and their Iberian breed relatives. Results: Using allelic genetic models and Fst analyses of ~50 K single nucleotide polymorphisms (SNPs) across the horse...
Shoemaker L, Clauset A.Horses (family Equidae) are a classic example of adaptive radiation, exhibiting a nearly 60-fold increase in maximum body mass and a peak taxonomic diversity of nearly 100 species across four continents. Such patterns are commonly attributed to niche competition, in which increased taxonomic diversity drives increased size disparity. However, neutral processes, such as macroevolutionary 'diffusion', can produce similar increases in disparity without increased diversity. Using a comprehensive database of Equidae species size estimates and a common mathematical framework, we measure the contribu...
How MJ, Zanker JM.The functional significance of the zebra coat stripe pattern is one of the oldest questions in evolutionary biology, having troubled scientists ever since Charles Darwin and Alfred Russel Wallace first disagreed on the subject. While different theories have been put forward to address this question, the idea that the stripes act to confuse or 'dazzle' observers remains one of the most plausible. However, the specific mechanisms by which this may operate have not been investigated in detail. In this paper, we investigate how motion of the zebra's high contrast stripes creates visual effects tha...
Wang HH, Kung NY, Grant WE, Scanlan JC, Field HE.Zoonoses from wildlife threaten global public health. Hendra virus is one of several zoonotic viral diseases that have recently emerged from Pteropus species fruit-bats (flying-foxes). Most hypotheses regarding persistence of Hendra virus within flying-fox populations emphasize horizontal transmission within local populations (colonies) via urine and other secretions, and transmission among colonies via migration. As an alternative hypothesis, we explore the role of recrudescence in persistence of Hendra virus in flying-fox populations via computer simulation using a model that integrates publ...
Prow NA.West Nile virus (WNV) is a mosquito-borne virus responsible for outbreaks of viral encephalitis in humans and horses, with particularly virulent strains causing recent outbreaks of disease in Eastern Europe, the Middle East and North America. A strain of WNV, Kunjin (WNVKUN), is endemic in northern Australia and infection with this virus is generally asymptomatic. However in early 2011, an unprecedented outbreak of encephalitis in horses occurred in south-eastern Australia, resulting in mortality in approximately 10%-15% of infected horses. A WNV-like virus (WNVNSW2011) was isolated and found ...
Krueger K, Flauger B, Farmer K, Hemelrijk C.Herds of ungulates, flocks of birds, swarms of insects and schools of fish move in coordinated groups. Computer models show that only one or very few animals are needed to initiate and direct movement. To investigate initiation mechanisms further, we studied two ways in which movement can be initiated in feral horses: herding, and departure from the group. We examined traits affecting the likelihood of a horse initiating movement i.e. social rank, affiliative relationships, spatial position, and social network. We also investigated whether group members join a movement in dominance rank order....
Cabrera-Guzmán E, Crossland MR, González-Bernal E, Shine R.Many invasive species exploit the disturbed habitats created by human activities. Understanding the effects of habitat disturbance on invasion success, and how disturbance interacts with other factors (such as biotic resistance to the invaders from the native fauna) may suggest new ways to reduce invader viability. In tropical Australia, commercial livestock production can facilitate invasion by the cane toad (Rhinella marina), because hoofprints left by cattle and horses around waterbody margins provide distinctive (cool, moist) microhabitats; nevertheless the same microhabitat can inhibit th...
Li X, Buzzard P, Chen Y, Jiang X.Alleviating human-carnivore conflict is central to large carnivore conservation and is often of economic importance, where people coexist with carnivores. In this article, we report on the patterns of predation and economic losses from wild carnivores preying on livestock in three villages of northern Baima Xueshan Nature Reserve, northwest Yunnan during a 2-year period between January 2010 and December 2011. We analyzed claims from 149 households that 258 head of livestock were predated. Wolves (Canis lupus) were responsible for 79.1 % of livestock predation; Asiatic black bears (Selenarctos ...
Krueger K, Farmer K, Heinze J.Social learning is said to meet the demands of complex environments in which individuals compete over resources and cooperate to share resources. Horses (Equus caballus) were thought to lack social learning skills because they feed on homogenously distributed resources with few reasons for conflict. However, the horse's social environment is complex, which raises the possibility that its capacity for social transfer of feeding behaviour has been underestimated. We conducted a social learning experiment using 30 socially kept horses of different ages. Five horses, one from each group, were chos...
Mughini-Gras L, Mulatti P, Severini F, Boccolini D, Romi R, Bongiorno G, Khoury C, Bianchi R, Montarsi F, Patregnani T, Bonfanti L, Rezza G....In Italy, West Nile virus (WNV) equine outbreaks have occurred annually since 2008. Characterizing WNV vector habitat requirements allows for the identification of areas at risk of viral amplification and transmission. Maxent-based ecological niche models were developed using literature records of 13 potential WNV Italian vector mosquito species to predict their habitat suitability range and to investigate possible geographical associations with WNV equine outbreak occurrence in Italy from 2008 to 2010. The contribution of different environmental variables to the niche models was also assessed...
Nuñez CM, Adelman JS, Rubenstein DI.Adoption of nongenetic offspring occurs in a variety of species but is rare in equids. We report a case of adoption by a free-ranging, feral mare Equus caballus and compare the maternal care received by her genetic offspring (born 1995) to that of her adopted offspring (born 1996) for the first 30 weeks of development. We compare five measures of care: (1) total time spent suckling, (2) mare aggression during suckling, (3) number of mare-terminated suckling bouts, (4) contact maintenance, and (5) mare-foal distance. For most behaviors, we detected no difference in the mare's treatment of the t...
Holmquist JG, Schmidt-Gengenbach J, Haultain SA.Grazing management necessarily emphasizes the most spatially extensive vegetation assemblages, but landscapes are mosaics, often with more mesic vegetation types embedded within a matrix of drier vegetation. Our primary objective was to contrast effects of equine grazing on both subalpine vegetation structure and associated arthropods in a drier reed grass (Calamagrostis muiriana) dominated habitat versus a wetter, more productive sedge habitat (Carex utriculata). A second objective was to compare reed grass and sedge as habitats for fauna, irrespective of grazing. All work was done in Sequoia...
van Beest FM, Uzal A, Vander Wal E, Laforge MP, Contasti AL, Colville D, McLoughlin PD.Density is a fundamental driver of many ecological processes including habitat selection. Theory on density-dependent habitat selection predicts that animals should be distributed relative to profitability of habitat, resulting in reduced specialization in selection (i.e. generalization) as density increases and competition intensifies. Despite mounting empirical support for density-dependent habitat selection using isodars to describe coarse-grained (interhabitat) animal movements, we know little of how density affects fine-grained resource selection of animals within habitats [e.g. using res...
Marjamäki PH, Contasti AL, Coulson TN, McLoughlin PD.Movement away from an area or social group in response to increasing density (density-dependent dispersal) is known for most species; why it evolves is fundamental to our understanding of ecology and evolution. However, we have yet to fully appreciate how individuals of varying conditions (e.g., age and sex) might differently consider effects of density (quorum) when deciding to disperse or not, and scale dependence in their sense of quorum. We tracked movements of all individuals of a naturalized population of feral horses (Equus ferus caballus; Sable Island National Park Reserve, Nova Scotia...
Alba A, Allepuz A, Napp S, Soler M, Selga I, Aranda C, Casal J, Pages N, Hayes EB, Busquets N.To enhance early detection of West Nile virus (WNV) transmission, an integrated ecological surveillance system was implemented in Catalonia (north-eastern Spain) from 2007 to 2011. This system incorporated passive and active equine surveillance, periodical testing of chicken sentinels in wetland areas, serosurveillance wild birds and testing of adult mosquitoes. Samples from 298 equines, 100 sentinel chickens, 1086 wild birds and 39 599 mosquitoes were analysed. During these 5 years, no acute WNV infection was detected in humans or domestic animal populations in Catalonia. WNV was not detect...
MacFadden BJ.The dispersal of Equus into South America during the Great American Biotic Interchange (GABI) represented a major event for Pleistocene land-mammal age chronology on that continent. It has been argued that this dispersal occurred during the late Pleistocene, ∼0.125 Ma, and it defines the base of the Lujanian South American Land Mammal Age (SALMA). In this scenario, Equus dispersed during the fourth and latest recognized phase of the interchange, i.e., GABI 4. Although Equus was widely distributed in South America during the Pleistocene, only a few localities are calibrated by independent chr...
Winton CL, Hegarty MJ, McMahon R, Slavov GT, McEwan NR, Davies-Morel MC, Morgan CM, Powell W, Nash DM.The conservation of unique populations of animals is critical in order to preserve valuable genetic diversity and, where populations are free-living, maintain their irreplaceable influence upon habitat ecology. An accurate assessment of genetic diversity and structure within and between populations is crucial in order to design and implement conservation strategies in natural and domesticated species. Moreover, where it is possible to identify relic populations that are related to a structured breed an ideal opportunity presents itself to model processes that reveal historical factors that hav...
Ransom JI, Hobbs NT, Bruemmer J.Abiotic inputs such as photoperiod and temperature can regulate reproductive cyclicity in many species. When humans perturb this process by intervening in reproductive cycles, the ecological consequences may be profound. Trophic mismatches between birth pulse and resources in wildlife species may cascade toward decreased survival and threaten the viability of small populations. We followed feral horses (Equus caballus) in three populations for a longitudinal study of the transient immunocontraceptive porcine zona pellucida (PZP), and found that repeated vaccinations extended the duration of in...
Huang ZY, de Boer WF, van Langevelde F, Olson V, Blackburn TM, Prins HH.Hosts species for multi-host pathogens show considerable variation in the species' reservoir competence, which is usually used to measure species' potential to maintain and transmit these pathogens. Although accumulating research has proposed a trade-off between life-history strategies and immune defences, only a few studies extended this to host species' reservoir competence. Using a phylogenetic comparative approach, we studied the relationships between some species' life-history traits and reservoir competence in three emerging infectious vector-borne disease systems, namely Lyme disease, W...
Lubelczyk C, Mutebi JP, Robinson S, Elias SP, Smith LB, Juris SA, Foss K, Lichtenwalner A, Shively KJ, Hoenig DE, Webber L, Sears S, Smith RP.From July to September, 2009, an outbreak of eastern equine encephalitis virus (EEEv) occurred in five counties in Maine. The virus was isolated from 15 horses, 1 llama, and pheasants in three separate captive flocks. One wild turkey, screened before translocation, also showed exposure to the virus in January 2010. Two pools of Culiseta melanura (Coquillett) tested positive for EEEv during routine seasonal surveillance in York County in September, but none of the mosquitoes collected during rapid response surveys tested positive. There were more Cs. melanura in July, August, and September 2009...
Girard TL, Bork EW, Nielsen SE, Alexander MJ.Public lands occupied by feral horses in North America are frequently managed for multiple uses with land use conflict occurring among feral horses, livestock, wildlife, and native grassland conservation. The factors affecting habitat use by horses is critical to understand where conflict may be greatest. We related horse presence and abundance to landscape attributes in a GIS to examine habitat preferences using 98 field plots sampled within a portion of the Rocky Mountain Forest Reserve of SW Alberta, Canada. Horse abundance was greatest in grassland and cut block habitats, and lowest in con...
Beschta RL, Donahue DL, DellaSala DA, Rhodes JJ, Karr JR, O'Brien MH, Fleischner TL, Deacon Williams C.Climate change affects public land ecosystems and services throughout the American West and these effects are projected to intensify. Even if greenhouse gas emissions are reduced, adaptation strategies for public lands are needed to reduce anthropogenic stressors of terrestrial and aquatic ecosystems and to help native species and ecosystems survive in an altered environment. Historical and contemporary livestock production-the most widespread and long-running commercial use of public lands-can alter vegetation, soils, hydrology, and wildlife species composition and abundances in ways that exa...
Vander Kelen PT, Downs JA, Stark LM, Loraamm RW, Anderson JH, Unnasch TR.Eastern Equine Encephalitis virus (EEEV) is an alphavirus with high pathogenicity in both humans and horses. Florida continues to have the highest occurrence of human cases in the USA, with four fatalities recorded in 2010. Unlike other states, Florida supports year-round EEEV transmission. This research uses GIS to examine spatial patterns of documented horse cases during 2005-2010 in order to understand the relationships between habitat and transmission intensity of EEEV in Florida. Methods: Cumulative incidence rates of EEE in horses were calculated for each county. Two cluster analyses wer...
Contasti AL, Tissier EJ, Johnstone JF, McLoughlin PD.Fine-scale spatial variation in genetic relatedness and inbreeding occur across continuous distributions of several populations of vertebrates; however, the basis of observed variation is often left untested. Here we test the hypothesis that prior observations of spatial patterns in genetics for an island population of feral horses (Sable Island, Canada) were the result of spatial variation in population dynamics, itself based in spatial heterogeneity in underlying habitat quality. In order to assess how genetic and population structuring related to habitat, we used hierarchical cluster analys...
Hernández-Jover M, Roche S, Ward MP.Vector-borne diseases can have substantial impacts on human and animal health, including major epidemics. West Nile virus (WNV) is of particular international importance due to its recent emergence and impact in the Western Hemisphere. Despite the presence of a sub-type of WNV (Kunjin virus, KUN) in Australia, a potential ecological niche could be occupied by an exotic strain of WNV of the North American type. This study assesses the probability an exotic strain of WNV enters Australia via an infected mosquito in an aircraft from the United States (U.S.) landing at Sydney airport, the probabil...
St-Pierre B, de la Fuente G, O'Neill S, Wright AD, Al Jassim R.We investigated the community structure of bacteria that populate the stomach of the Brumby, a breed of feral horses from the Australian outback. Using a 16S rRNA gene clone library, we identified 155 clones that were assigned to 26 OTUs based on a 99.0 % sequence identity cutoff. Two OTUs represented 73.5 % of clones, while 18 OTUs were each assigned only a single clone. Four major bacterial types were identified in the Brumby stomach: Lactobacillaceae, Streptococcaceae, Veillonellaceae and Pasteurellaceae. The first three groups, which represented 98.1 % of the Brumby stomach library clones,...
Onogi A, Shirai K, Amano T.Because native breeds can serve as genetic resources for adapting to environment changes, their conservation is important for future agroecosystems. Using pedigree analysis, we investigated genetic diversity and inbreeding in Japanese Hokkaido native horses, which have adapted to a cold climate and roughage diet. Genetic diversity was measured as the number of founders and the effective number of founders, ancestors and genomes. All metrics imply a decrease in genetic diversity. A comparison of these metrics suggested that pedigree bottlenecks contributed more than did random gene losses to th...
Bernátková A, Oyunsaikhan G, Šimek J, Komárková M, Bobek M, Ceacero F.Reintroduction is a common technique for re-establishing threatened species. However, the adaptation to novel habitats with distinct conditions poses a risk of failure. Weather conditions affect the behaviour of animals, and thus, their adaptation to new conditions and survival. Reintroduced Przewalski's horses living in Mongolia's continental arid climate with extreme temperature and precipitation variability, serve as an ideal model species for studying the behavioural response of selected groups to these harsh conditions. Methods: The research was conducted in The Great Gobi B Strictly Prot...
Tang Y, Liu G, Zhao S, Li K, Zhang D, Liu S, Hu D.Major histocompatibility complex (MHC) genes are the most polymorphic in vertebrates and the high variability in many MHC genes is thought to play a crucial role in pathogen recognition. The MHC class II locus DQA polymorphism was analyzed in the endangered Przewalski's horse, , a species that has been extinct in the wild and all the current living individuals descend from 12 founders. We used the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) to detect the polymorphism within the MHC DQA in 31 Przewalski's horses from two reintroduced populations. Consequently, o...
Feist JD, McCullough DR.A behavioural study of feral horses was conducted on the Pryor Mountain Wild Horse Range in the western United States. All 270 horses on the Range were identified individually. The sex ratio was nearly balanced. Foal to adult female ratio was 43-2:100. Morality was concentrated among foals and old horses. Horses were organized as forty-four harem groups each with a dominant stallion, one to two immature stallions, one to three immature mares, one to three adult mares and their yearling and foal offspring, and 23 bachelor groups of one to eight stallions. Harem groups were quite stable year-rou...
Perera NN, Weston PA, Barrow RA, Weston LA, Gurr GM.Volatile cues can play a significant role in the location and discrimination of food resources by insects. Dung beetles have been reported to discriminate among dung types produced by different species, thereby exhibiting behavioral preferences. However, the role of volatile organic compounds (VOCs) in dung localization and preference remains largely unexplored in dung beetles. Here we performed several studies: firstly, cage olfactometer bioassays were performed to evaluate the behavioral responses of (Coleoptera: Scarabaeidae) to VOCs emanating from fresh horse, sheep, and cattle dung; seco...
Chen J, Weng Q, Chao J, Hu D, Taya K.In China, the first Przewalski's horse (Equus przewalskii) group was released in Kalamaili Ungulate Protected Area in Xinjiang, in August 2001. The objective of this study was to investigate reproduction and development of released Przewalski's horses in Xinjiang, China from 2002 to 2006. Twenty-four descendants were naturally born, average reproduction rate was 38.7%, and average survival rate of foals was 69.1% in this interim. Frequent alternation of the leading stallion and infertility in female horses due to environmental factors were main causes for the low reproduction rate. The infant ...
Polley L.Each month for a 1-year period (October through September), equine fecal masses containing eggs of strongylid nematodes were placed outdoors on small grass plots in Saskatchewan, Canada. Thereafter, feces and grass from the plots were sampled after intervals of 1 week or longer, and the strongylid eggs and larvae recovered were counted. These observations were made over a 2-year period. Development of eggs to infective larvae occurred in all experiments, except those established in October, December, and January. Infective larvae from experiments set up in April through September survived that...
Tolesano-Pascoli GV, Torga K, Franchin AG, Ogrzewalska M, Gerardi M, Olegário MM, Labruna MB, Szabó MP, Marçal Júnior O.This is a report of tick species, parasite prevalence and infestation intensity of birds in a forest fragment (18° 56' 57'' S and 48° 12' 14'' W) within the Brazilian cerrado (savanna), in the municipality of Uberlândia, State of Minas Gerais, Brazil. A total of 162 birds from 26 species were captured. One adult tick, 296 larvae and 67 nymphs were found on passerine birds. Of these, it was identified 31 larvae and 27 nymphs of Amblyomma longirostre, 17 nymphs of A. nodosum, one A. cajennense larvae and one male of Rhipicephalus sanguineus. All other ticks were identified as Amblyomma sp. la...
Eronen JT, Evans AR, Fortelius M, Jernvall J.One of the classic examples of faunal turnover in the fossil record is the Miocene transition from faunas dominated by anchitheriine horses with low-crowned molar teeth to faunas with hipparionine horses characterized by high-crowned teeth. The spread of hipparionine horses is associated with increased seasonality and the expansion of open habitats. It is generally accepted that anchitheriine horses did not display an evolutionary increase in tooth crown height prior to their extinction. Nevertheless, to test whether anchitheriines showed any changes interpretable as adaptation to local condit...
Flegal AR, Gallon C, Hibdon S, Kuspa ZE, Laporte LF.Analyses of lead concentration and isotopic composition of recent and archived samples of the lace lichen (Ramalina menziesii) chronicle more than a century of atmospheric lead contamination in central California. The contamination extends back to our oldest sample from 1892, when lead levels in lichen from the northern reach of the San Francisco Bay estuary were 9-12 microg/g and their isotopic composition corresponded to those of high lead emissions from the Selby smelter (e.g., (206)Pb/(207)Pb = 1.165) that were killing horses in adjacent fields at that time. By the mid-1950s lead isotopic ...
Muscatello G, Browning GF.Selective agar media have been used for many years to facilitate the isolation of Rhodococcus equi from environmental and clinical samples. However, characterisation of R. equi still requires the use of immunochemical or polymerase chain reaction (PCR) analysis to differentiate between virulent and avirulent isolates. Here, we describe a novel method to detect and differentiate between R. equi isolates using colony blotting and DNA hybridization. Radiolabelled PCR product derived from the R. equi rrnA gene and specific hybridization conditions enabled differentiation of colonies of R. equi fro...
Berezin VV.Virologic and serological surveys of wild vertebrates carried out in various provinces of Cuba demonstrated definitely that birds were the main hosts of eastern equine encephalomyelitis (EEE) virus in this territory. Fifteen strains of this virus were isolated from 8 species of birds belonging to 5 orders. Isolation of EEE virus from the blood of the endemic genus of iguanas indicates a certain role of cold-blooded animals in the ecology of this agent. Active EEE virus foci have been found in 4 provinces of the Republic of Cuba: Pinar del Rio, Havana, Matanzas and Las Villas. Isolation of a nu...
Tantely ML, Guis H, Randriananjantenaina I, Raharinirina MR, Velonirina HJ, Cardinale E, Raveloarijaona N, Cêtre-Sossah C, Garros C, Girod R.In Madagascar, the high West Nile virus (WNV) antibody prevalence reported in horse populations suggests a high level of vector-horse contact. This study aims to characterize the mosquito species usually involved in WNV transmission in horse stables in Madagascar. Five horse stables were investigated in October and November 2016 in five distinct inland areas. Mosquitoes were collected using double net traps baited with human, poultry or horse as well as light traps. Blood meal identification from engorged females was performed using host-specific PCRs. A total of 2898 adult mosquitoes were col...
Kirkpatrick JF.There are few wildlife populations existing today that can be supported without some form of management. Wildlife fertility control, as one option, has moved from the research stage to actual application with a number of species, including wild horses, urban deer, captive exotic species and even African elephants, but this approach remains controversial in many quarters. Strident debate has arisen over the possible effects of contraception on behaviour, genetics, stress and even management economics, among other parameters. Part of the debate arises from the fact that critics often fail to rec...
Comer JA, Irby WS, Kavanaugh DM.Hosts of Lutzomyia shannoni Dyar, a suspected biological vector of the New Jersey serotype of vesicular stomatitis (VSNJ) virus, were determined using an indirect enzyme-linked immunosorbent assay (ELISA) of 333 blood-fed female sandflies collected from their diurnal resting shelters on Ossabaw Island, Georgia, U.S.A. Sandflies had fed primarily on white-tailed deer (Odocoileus virginianus) (81%) and to a lesser extent on feral swine (Sus scrofa) (16%), two species of host infected annually with VSNJ. Other hosts were raccoons (Procyon lotor) and horses (Equus caballus) or donkeys (E. asinus),...
Bast TF, Whitney E, Benach JL.In September 1970 three horses in eastern Long Island were clinically diagnosed
as having Eastern equine encephalomyelitis (EEE). At this time, EEE virus was isolated
from the blood clots of three migrating Northern Yellow-shafted Flickers, and from the brain
and liver of another Northern Yellow-shafted Flicker (Colaptes auratus lutetts). Following
this episode, a I-year arbovirus survey was conducted beginning in September 1970. Serologic
surveys indicated widespread prevalence of EEE antibodies in the avian population and also
low grade activity in various mammals. Powassan and St. Lou...
Barton MD, Hughes KL.A total of 189 isolates of Rhodococcus equi and related organisms and 16 marker strains representing the genera Rhodococcus and Corynebacterium were screened for 160 unit characters in a numerical taxonomic study. Analysis of the data indicated that R. equi forms a relatively homogeneous cluster distinctly separated from the recognized species of Rhodococcus and Corynebacterium (sensu stricto). Other members of the genus Rhodococcus are soil organisms and R. equi appears to fit into the genus on ecological as well as taxonomic grounds. It seems unlikely that R. equi could be a gastrointestinal...
Vega-Pla JL, Calderón J, Rodríguez-Gallardo PP, Martinez AM, Rico C.In the 1980s, a conservation programme involving a feral horse population, the Retuertas horses from the Guadalquivir marshes, was started in the Doñana National Park. The analysis of an extensive genetic survey of this population, which now numbers 100 animals, and 10 additional European and North African breeds using DNA polymorphisms from 22 microsatellites is presented. Highly significant fixation indexes were obtained for all pairwise comparisons between the Retuertas population and other breeds. A population neighbour-joining breed phenogram was built using different distance measures, ...
Silliman BR, Mozdzer T, Angelini C, Brundage JE, Esselink P, Bakker JP, Gedan KB, van de Koppel J, Baldwin AH.Invasive species threaten biodiversity and incur costs exceeding billions of US$. Eradication efforts, however, are nearly always unsuccessful. Throughout much of North America, land managers have used expensive, and ultimately ineffective, techniques to combat invasive Phragmites australis in marshes. Here, we reveal that Phragmites may potentially be controlled by employing an affordable measure from its native European range: livestock grazing. Experimental field tests demonstrate that rotational goat grazing (where goats have no choice but to graze Phragmites) can reduce Phragmites cover f...
Girard TL, Bork EW, Nielsen SE, Alexander MJ.Public lands occupied by feral horses in North America are frequently managed for multiple uses with land use conflict occurring among feral horses, livestock, wildlife, and native grassland conservation. The factors affecting habitat use by horses is critical to understand where conflict may be greatest. We related horse presence and abundance to landscape attributes in a GIS to examine habitat preferences using 98 field plots sampled within a portion of the Rocky Mountain Forest Reserve of SW Alberta, Canada. Horse abundance was greatest in grassland and cut block habitats, and lowest in con...
Anderson RA, Gallaway WJ.The capillary tube precipitin test was used to determine the host utilization patterns of Culiseta inornata in southwestern Manitoba. Ruminant blood was identified in 83.3% and equine blood in 15.8% of 1,036 positively reacting blood-meals. Human, swine and avian blood accounted for 0.9% of these blood-meals and mixed blood-meals accounted for 1.5% of the total. Culiseta inornata preferentially fed on large mammals, and selection between cattle and horses reflected the relative abundance of these two hosts rather than a specific preference for either one.
Barrón-Ortiz CI, Rodrigues AT, Theodor JM, Kooyman BP, Yang DY, Speller CF.Horses were a dominant component of North American Pleistocene land mammal communities and their remains are well represented in the fossil record. Despite the abundant material available for study, there is still considerable disagreement over the number of species of Equus that inhabited the different regions of the continent and on their taxonomic nomenclature. In this study, we investigated cheek tooth morphology and ancient mtDNA of late Pleistocene Equus specimens from the Western Interior of North America, with the objective of clarifying the species that lived in this region prior to t...
Elghandour MMMY, Adegbeye MJ, Barbabosa-Pilego A, Perez NR, Hernández SR, Zaragoza-Bastida A, Salem AZM.Greenhouses gas emission mitigation is a very important aspect of earth sustainability with greenhouse gasses reduction, a focus of agricultural and petrochemical industries. Methane is produced in nonruminant herbivores such as horses because they undergo hindgut fermentation. Although equine produce less methane than ruminant, increasing population of horses might increase their contribution to the present 1.2 to 1.7 Tg, estimate. Diet, feeding frequency, season, genome, and protozoa population influence methane production equine. In population, Methanomicrobiales, Methanosarcinales, Methan...
Vorobieva NV, Makunin AI, Druzhkova AS, Kusliy MA, Trifonov VA, Popova KO, Polosmak NV, Molodin VI, Vasiliev SK, Shunkov MV, Graphodatsky AS.A growing number of researchers studying horse domestication come to a conclusion that this process happened in multiple locations and involved multiple wild maternal lines. The most promising approach to address this problem involves mitochondrial haplotype comparison of wild and domestic horses from various locations coupled with studies of possible migration routes of the ancient shepherds. Here, we sequenced complete mitochondrial genomes of six horses from burials of the Ukok plateau (Russia, Altai Mountains) dated from 2.7 to 1.4 thousand years before present and a single late Pleistocen...
Thirstrup JP, Bach LA, Loeschcke V, Pertoldi C.In this study, we performed a population viability analysis on 3 domestic horse breeds (Equus caballus) of Danish origin, namely, the Frederiksborg, the Knabstrupper, and the Jutland breeds. Because of their small population sizes, these breeds are considered endangered. The Vortex software simulation package was used for the population viability analysis. First, we investigated the future viability of these breeds based on present demographic and environmental parameters. Second, a sensitivity analysis revealed the most important variables for the viability of these breeds. Third, we examined...
Ostermann-Kelm SD, Atwill EA, Rubin ES, Hendrickson LE, Boyce WM.Free-ranging horses (Equus caballus) in North America are considered to be feral animals since they are descendents of non-native domestic horses introduced to the continent. We conducted a study in a southern California desert to understand how feral horse movements and horse feces impacted this arid ecosystem. We evaluated five parameters susceptible to horse trampling: soil strength, vegetation cover, percent of nonnative vegetation, plant species diversity, and macroinvertebrate abundance. We also tested whether or not plant cover and species diversity were affected by the presence of hors...
Castellaro G, Orellana CL, Escanilla JP.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%), differ...
