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a multivalent mannheimia/bibersteinia vaccine protects bighorn sheep against mannheimia haemolytica challenge.bighorn sheep (bhs) are more susceptible than domestic sheep (ds) to mannheimia haemolytica pneumonia. although both species carry m. haemolytica as a commensal bacterium in the nasopharynx, ds carry mostly leukotoxin (lkt)-positive strains while bhs carry lkt-negative strains. consequently, antibodies to surface antigens and lkt are present at much higher titers in ds, but lower in bhs. the objective of this study was to determine whether repeated immunization of bhs with multivalent mannheimia ...201121832104
sex ratio bias and reproductive strategies: what sex to produce when?several theories predict the evolution of bias in progeny sex ratio based on variations in maternal or offspring reproductive value. for mammals, however, tests of sex-bias theories have produced inconsistent results, and no clear patterns have emerged. each theory is based on assumptions that are difficult to satisfy, and empirical tests require large data sets. using a long-term study on bighorn sheep (ovis canadensis), we identified several parameters that influence progeny sex ratio accordin ...201121618923
qtl mapping for sexually dimorphic fitness-related traits in wild bighorn sheep.dissecting the genetic architecture of fitness-related traits in wild populations is key to understanding evolution and the mechanisms maintaining adaptive genetic variation. we took advantage of a recently developed genetic linkage map and phenotypic information from wild pedigreed individuals from ram mountain, alberta, canada, to study the genetic architecture of ecologically important traits (horn volume, length, base circumference and body mass) in bighorn sheep. in addition to estimating s ...201121847139
Common functional correlates of head-strike behavior in the pachycephalosaur Stegoceras validum (Ornithischia, Dinosauria) and combative artiodactyls.Pachycephalosaurs were bipedal herbivorous dinosaurs with bony domes on their heads, suggestive of head-butting as seen in bighorn sheep and musk oxen. Previous biomechanical studies indicate potential for pachycephalosaur head-butting, but bone histology appears to contradict the behavior in young and old individuals. Comparing pachycephalosaurs with fighting artiodactyls tests for common correlates of head-butting in their cranial structure and mechanics.201121738658
finite element analysis of ramming in ovis canadensis.the energy produced during the ramming of bighorn sheep (ovis canadensis) would be expected to result in undesirable stresses in their frontal skull, which in turn would cause brain injury; yet, this animal seems to suffer no ill effects. in general, horn is made of an a-keratin sheath covering a bone. despite volumes of data on the ramming behavior of ovis canadensis, the extent to which structural components of horn and horn-associated structure or tissue absorb the impact energy generated by ...201121280881
wildlife translocation: the conservation implications of pathogen exposure and genetic heterozygosity.a key challenge for conservation biologists is to determine the most appropriate demographic and genetic management strategies for wildlife populations threatened by disease. we explored this topic by examining whether genetic background and previous pathogen exposure influenced survival of translocated animals when captive-bred and free-ranging bighorn sheep (ovis canadensis) were used to re-establish a population that had been extirpated in the san andres mountains in new mexico, usa.201121284886
predator-driven component allee effects in a wild ungulate.negative density dependence is an important driver of population dynamics of large vertebrates. allee effects (positive density dependence), however, can affect small populations. allee effects can be generated by predation and recent research has revealed potentially important indirect effects of predation on population dynamics. for wild populations, however, quantification of both allee effects and indirect effects of predation remains scarce. we monitored for 27 years a bighorn sheep (ovis c ...201121320261
co-expression of ovine lps receptor cd14 with mannheimia haemolytica leukotoxin receptor lfa-1 or mac-1 does not enhance leukotoxin-induced cytotoxicity.leukotoxin (lkt) and lps are the major virulence determinants of mannheimia haemolytica that contribute to the pathogenesis of bovine and ovine pneumonic pasteurellosis. we have previously identified bovine and ovine cd18 as the functional receptor for lkt. lps complexes with lkt resulting in increased thermal stability and enhanced cytotoxic activity of lkt. cellular recognition of lps involves several different molecules including cd14. we hypothesized that expression of ovine cd14 together wi ...201121420740
a genome-wide set of snps detects population substructure and long range linkage disequilibrium in wild sheep.the development of genomic resources for wild species is still in its infancy. however, cross-species utilization of technologies developed for their domestic counterparts has the potential to unlock the genomes of organisms that currently lack genomic resources. here, we apply the ovinesnp50 beadchip, developed for domestic sheep, to two related wild ungulate species: the bighorn sheep (ovis canadensis) and the thinhorn sheep (ovis dalli). over 95% of the domestic sheep markers were successfull ...201121429138
comparison of passively transferred antibodies in bighorn and domestic lambs reveals one factor in differential susceptibility of these species to mannheimia haemolytica-induced pneumonia.mannheimia haemolytica consistently causes fatal bronchopneumonia in bighorn sheep (bhs, ovis canadensis) under natural and experimental conditions. leukotoxin is the primary virulence factor of this organism. bhs are more susceptible to developing fatal pneumonia in comparison to the related species domestic sheep (ds, ovis aries). in bhs herds affected by pneumonia, lamb recruitment is severely impaired for years subsequent to an outbreak. we hypothesized that a lack of maternally derived anti ...201121613459
pasteurellaceae from colorado bighorn sheep herds.we compared phenotypic and genotypic characterizations of 88 pasteurellaceae isolates from bighorn sheep (ovis canadensis) in the course of exploring epizootiologic relationships. based on our observations, adopting contemporary taxonomic conventions and using molecular methods to detect and compare pasteurellaceae may help improve understanding of bighorn respiratory disease epizootiology and management.201121719858
defective bacterial clearance is responsible for the enhanced lung pathology characteristic of mannheimia haemolytica pneumonia in bighorn sheep.the molecular and cellular basis for the enhanced lung pathology and mortality caused by mannheimia haemolytica in bighorn sheep (bhs, ovis canadenesis), in comparison to domestic sheep (ds, ovis aries), is not clear. polymorphonuclear leukocytes (pmns) of bhs are four- to eight-fold more susceptible to m. haemolytica leukotoxin-induced cytolysis, which is likely to reduce the number of functional phagocytes in the lung. we hypothesized that enhanced lung pathology is due to defective clearance ...201121742446
Translating effects of inbreeding depression on component vital rates to overall population growth in endangered bighorn sheep.Evidence of inbreeding depression is commonly detected from the fitness traits of animals, yet its effects on population growth rates of endangered species are rarely assessed. We examined whether inbreeding depression was affecting Sierra Nevada bighorn sheep (Ovis canadensis sierrae), a subspecies listed as endangered under the U.S. Endangered Species Act. Our objectives were to characterize genetic variation in this subspecies; test whether inbreeding depression affects bighorn sheep vital ra ...201122070275
shared bacterial and viral respiratory agents in bighorn sheep (ovis canadensis), domestic sheep (ovis aries), and goats (capra hircus) in montana.transmission of infectious agents from livestock reservoirs has been hypothesized to cause respiratory disease outbreaks in bighorn sheep (ovis canadensis), and land management policies intended to limit this transmission have proven controversial. this cross-sectional study compares the infectious agents present in multiple populations of bighorn sheep near to and distant from their interface with domestic sheep (o. aries) and domestic goat (capra hircus) and provides critical baseline informat ...201122195293
rapid decrease in horn size of bighorn sheep: environmental decline, inbreeding depression, or evolutionary response to trophy hunting?there are numerous examples demonstrating that selection has greatly influenced phenotypes in wild-harvested species. here, a significant reduction in horn size in trophy desert bighorn sheep rams over 30 years in a reintroduced population in aravaipa canyon, arizona is documented. after examining the potential effects of a detrimental change in the environment, inbreeding depression, and hunter-caused evolutionary change, it appears that environmental deterioration, apparently from the effects ...201121900210
Bighorn sheep from Yakutia. 201121953234
patterns of body mass senescence and selective disappearance differ among three species of free-living ungulates.declines in survival and reproduction with age are prevalent in wild vertebrates, but we know little about longitudinal changes in behavioral, morphological, or physiological variables that may explain these demographic declines. we compared age-related variation in body mass of adult females in three free-living ungulate populations that have been the focus of long-term, individual-based research: bighorn sheep (ovis canadensis) at ram mountain, canada; roe deer (capreolus capreolus) at trois f ...201122073785
survival of bighorn sheep (ovis canadensis) commingled with domestic sheep (ovis aries) in the absence of mycoplasma ovipneumoniae.to test the hypothesis that mycoplasma ovipneumoniae is an important agent of the bighorn sheep (ovis canadensis) pneumonia that has previously inevitably followed experimental commingling with domestic sheep (ovis aries), we commingled m. ovipneumoniae-free domestic and bighorn sheep (n=4 each). one bighorn sheep died with acute pneumonia 90 days after commingling, but the other three remained healthy for >100 days. this unprecedented survival rate is significantly different (p=0.002) from that ...201222247385
occurrence, diagnosis, and strain typing of mycobacterium avium subspecies paratuberculosis infection in rocky mountain bighorn sheep (ovis canadensis canadensis) in southwestern alberta.the role that wildlife may play in the transmission of mycobacterium avium subspecies paratuberculosis (map), the causative agent of johne's disease (jd), and the potential consequences of infection in these populations are being given increasing consideration. a yearling male rocky mountain bighorn sheep (ovis canadensis canadensis) from southwestern alberta, canada, was found infected with map in august 2009. clinical signs of emaciation and diarrhea and histologic findings of diffuse granulom ...201222247368
genomic consequences of genetic rescue in an insular population of bighorn sheep (ovis canadensis).genetic rescue is a management intervention whereby a small population is supplemented with individuals from other populations in an attempt to reverse the effects of inbreeding and increased genetic load. one such rescue was recently documented in the population of bighorn sheep (ovis canadensis) within the national bison range wildlife refuge (montana, usa). here, we examine the locus-specific effects of rescue in this population using a newly developed genome-wide set of 195 microsatellite lo ...201222257293
short reads, circular genome: skimming solid sequence to construct the bighorn sheep mitochondrial genome.as sequencing technology improves, an increasing number of projects aim to generate full genome sequence, even for nonmodel taxa. these projects may be feasibly conducted at lower read depths if the alignment can be aided by previously developed genomic resources from a closely related species. we investigated the feasibility of constructing a complete mitochondrial (mt) genome without preamplification or other targeting of the sequence. here we present a full mt genome sequence (16,463 nucleoti ...201221948953
data from selective harvests underestimate temporal trends in quantitative traits.human harvests can select against phenotypes favoured by natural selection, and natural resource managers should evaluate possible artificial selection on wild populations. because the required genetic data are extremely difficult to gather, however, managers typically rely on harvested animals to document temporal trends. it is usually unknown whether these data are unbiased. we explore our ability to detect a decline in horn size of bighorn sheep (ovis canadensis) by comparing harvested males ...201222552634
proximity-dependent inhibition of growth of mannheimia haemolytica by pasteurella multocida.mannheimia haemolytica, pasteurella multocida, and bibersteinia trehalosi have been identified in the lungs of pneumonic bighorn sheep (bhs; ovis canadensis). of these pathogens, m. haemolytica has been shown to consistently cause fatal pneumonia in bhs under experimental conditions. however, m. haemolytica has been isolated by culture less frequently than the other bacteria. we hypothesized that the growth of m. haemolytica is inhibited by other bacteria in the lungs of bhs. the objective of th ...201222798357
pasteurellaceae isolated from bighorn sheep (ovis canadensis) from idaho, oregon, and wyoming.to elucidate the species and biovariants of pasteurellaceae isolated from clinically normal bighorn sheep (ovis canadensis) or bighorn sheep with evidence of respiratory disease.201222738054
causes of pneumonia epizootics among bighorn sheep, western united states, 2008-2010.epizootic pneumonia of bighorn sheep is a devastating disease of uncertain etiology. to help clarify the etiology, we used culture and culture-independent methods to compare the prevalence of the bacterial respiratory pathogens mannheimia haemolytica, bibersteinia trehalosi, pasteurella multocida, and mycoplasma ovipneumoniae in lung tissue from 44 bighorn sheep from herds affected by 8 outbreaks in the western united states. m. ovipneumoniae, the only agent detected at significantly higher prev ...201222377321
mhc class ii dr allelic diversity in bighorn sheep.we hypothesized that decreased diversity and/or unique polymorphisms in mhc class ii alleles of bighorn sheep (bhs, ovis canadensis) are responsible for lower titer of antibodies against mannheimia haemolytica leukotoxin, in comparison to domestic sheep (ds, ovis aries). to test this hypothesis, dra and drb transcripts from 24 captive bhs (ovca-dra and ovca-drb) were sequenced. based on exon 2 (β1 domain) sequences, eight different ovca-drb cdna sequences were identified in bhs. six of them were ...201222750296
detection of mycoplasma ovipneumoniae and m. arginini in bighorn sheep using enrichment culture coupled with genus- and species-specific polymerase chain reaction.mycoplasma species are of interest as possible primary pathogens in the pneumonia complex of bighorn sheep (ovis canadensis). previous investigations have not commonly detected low frequencies of mycoplasma spp. from free-ranging bighorn sheep, possibly due to the fastidious and slow growth of these organisms. we developed a culture protocol that employed an average initial 3-day enrichment culture in liquid hayflick broth in a co(2)-enhanced atmosphere. the broth was plated to solid hayflick me ...201222493120
efficacy of a portable oxygen concentrator with pulsed delivery for treatment of hypoxemia during anesthesia of wildlife.portable battery-driven oxygen concentrators provide an alternative to the use of oxygen cylinders for treatment of hypoxemia during field anesthesia. the aim of this study was to evaluate the use of the evergo portable oxygen concentrator (respironics, murrysville, pennsylvania 15668, usa) with pulse-dose delivery for improvement of arterial oxygenation during anesthesia of wildlife. this concentrator delivers oxygen in a pulsed flow with pulse volumes from 12 to 70 ml, up to a maximum capacity ...201222448511
reference intervals for mineral concentrations in whole blood and serum of bighorn sheep (ovis canadensis) in california.whole blood and serum mineral concentrations were measured in diverse bighorn sheep (ovis canadensis) metapopulations in california, and 90% reference intervals were determined. while there were some statistical differences between median concentrations among the different metapopulations, detected values were generally in good agreement with concentrations reported for other bighorn sheep populations and with reference ranges widely accepted for domestic sheep (ovis aries). although median whol ...201222529120
detection probability and pasteurellaceae surveillance in bighorn sheep.we investigated the influence of detection probability (i.e., the probability of detecting the disease or organism of interest) on the repeatability of results reported from bacterial culture tests used to demonstrate the presence of species in the pasteurellaceae family that infect bighorn sheep (ovis canadensis). we also estimated occupancy probabilities (i.e., the probability an individual bighorn in a herd is infected) for each cultured biovariant and examined the effects of detection probab ...201222740525
a review of hypothesized determinants associated with bighorn sheep (ovis canadensis) die-offs.multiple determinants have been hypothesized to cause or favor disease outbreaks among free-ranging bighorn sheep (ovis canadensis) populations. this paper considered direct and indirect causes of mortality, as well as potential interactions among proposed environmental, host, and agent determinants of disease. a clear, invariant relationship between a single agent and field outbreaks has not yet been documented, in part due to methodological limitations and practical challenges associated with ...201222567546
cortisol and corticosterone independence in cortisol-dominant wildlife.species have traditionally been defined as cortisol-dominant or corticosterone-dominant, depending on the glucocorticoid that is reported. to assess the degree of covariance versus independence between cortisol and corticosterone, 245 serum samples belonging to 219 individuals from 18 cortisol-dominant, non-domesticated species (6 mammalian orders) were compared by mass spectrometry. in these samples, which were elevated above baseline, concentration ranges were overlapping for cortisol and cort ...201222449618
population genomics as a new tool for wildlife management.admixture and introgression have varied effects on population viability and fitness. admixture might be an important source of new alleles, particularly for small, geographically isolated populations. however, admixture might also cause outbreeding depression if populations are adapted to different ecological or climatic conditions. because of the emerging use of translocation and admixture as a conservation and wildlife management strategy to reduce genetic load (termed genetic rescue), the pos ...201222443425
evaluation of experimental genetic management in reintroduced bighorn sheep.positive demographic responses have been reported in several species where the immigration or supplementation of genetically distinct individuals into wild populations has resulted in a genetic rescue effect. however, rarely have researchers incorporated what could be considerable risk of outbreeding depression into planning for genetic management programs. we assess the genetic effects of an experiment in genetic management involving replicate populations of california bighorn sheep (ovis canad ...201222423334
evaluation of management treatments intended to increase lamb recruitment in a bighorn sheep herd.we administered a suite of treatments to a herd of rocky mountain bighorn sheep (ovis canadensis canadensis) that was experiencing poor lamb recruitment and showing signs of respiratory disease. despite 3 yr of treatment with various combinations of anthelmentics, antibiotics, vaccines, and hyperimmune serum products, recruitment was not improved.201222740546
free-ranging rocky mountain bighorn sheep and an outbreak of inflammatory bowel disease along the clark fork river in plains, montana.nine individuals with ulcerative colitis or crohn disease grew up or lived in plains, montana, a 1,200-person community adjacent to the clark fork river near herds of free ranging rocky mountain bighorn sheep. this inflammatory bowel disease outbreak is similar to others that have occurred along rivers contaminated by animal feces.201223076274
bighorn sheep may be at risk for tses. 201324236331
despite catch-up, prolonged growth has detrimental fitness consequences in a long-lived vertebrate.individuals experiencing poor growth early in life may later make up their size deficit. compensatory growth or growth prolongation may lead to such catch-up, involving different life-history trade-offs under natural conditions. frequent recaptures and detailed monitoring of animals surviving to asymptotic size are required to compare growth tactics and their fitness consequences. no study to date has obtained such detailed information for wild animals. we used repeated mass measurements (mean 1 ...201324231538
genomic resources notes accepted 1 april 2013-31 may 2013.this article documents the public availability of approximately 15 000 polymorphic snp loci for the bighorn sheep ovis canadensis.201323875910
spatio-temporal dynamics of pneumonia in bighorn sheep.1. bighorn sheep mortality related to pneumonia is a primary factor limiting population recovery across western north america, but management has been constrained by an incomplete understanding of the disease. we analysed patterns of pneumonia-caused mortality over 14 years in 16 interconnected bighorn sheep populations to gain insights into underlying disease processes. 2. we observed four age-structured classes of annual pneumonia mortality patterns: all-age, lamb-only, secondary all-age and a ...201323398603
use of exposure history to identify patterns of immunity to pneumonia in bighorn sheep (ovis canadensis).individual host immune responses to infectious agents drive epidemic behavior and are therefore central to understanding and controlling infectious diseases. however, important features of individual immune responses, such as the strength and longevity of immunity, can be challenging to characterize, particularly if they cannot be replicated or controlled in captive environments. our research on bighorn sheep pneumonia elucidates how individual bighorn sheep respond to infection with pneumonia p ...201323637929
the complete mitochondrial genome sequence analysis of tibetan argali (ovis ammon hodgsoni): implications of tibetan argali and gansu argali as the same subspecies.the genus ovis (bovidae, artiodactyla) includes six species, i.e. ovis ammon, ovis aries, ovis canadensis, ovis dalli, ovis nivicola and ovis vignei. based on morphology, geographical location, habitat, etc., the species o. ammon is divided into nine subspecies. the near threatened tibetan argali is distributed across the tibetan plateau and its peripheral mountains, and believed to be one of the o. ammon subspecies (o. a. hodgsoni). however, considering its morphological features and distributi ...201323542075
evaluating apparent competition in limiting the recovery of an endangered ungulate.predation can disproportionately affect endangered prey populations when generalist predators are numerically linked to more abundant primary prey. apparent competition, the term for this phenomenon, has been increasingly implicated in the declines of endangered prey populations. we examined the potential for apparent competition to limit the recovery of sierra nevada bighorn sheep (ovis canadensis sierrae), an endangered subspecies under the us endangered species act. using a combination of loc ...201322791131
bighorn sheep pneumonia: sorting out the cause of a polymicrobial disease.pneumonia of bighorn sheep (ovis canadensis) is a dramatic disease of high morbidity and mortality first described more than 80 years ago. the etiology of the disease has been debated since its initial discovery, and at various times lungworms, mannheimia haemolytica and other pasteurellaceae, and mycoplasma ovipneumoniae have been proposed as primary causal agents. a multi-factorial "respiratory disease complex" has also been proposed as confirmation of causation has eluded investigators. in th ...201323253148
role of bibersteinia trehalosi, respiratory syncytial virus, and parainfluenza-3 virus in bighorn sheep pneumonia.pneumonic bighorn sheep (bhs) have been found to be culture- and/or sero-positive for bibersteinia trehalosi, respiratory syncytial virus (rsv), and parainfluenza-3 virus (pi-3). the objective of this study was to determine whether these pathogens can cause fatal pneumonia in bhs. in the first study, two groups of four bhs each were intra-tracheally administered with leukotoxin-positive (group i) or leukotoxin-negative (group ii) b. trehalosi. all four animals in group i developed severe pneumon ...201323025980
seasonal foraging ecology of non-migratory cougars in a system with migrating prey.we tested for seasonal differences in cougar (puma concolor) foraging behaviors in the southern yellowstone ecosystem, a multi-prey system in which ungulate prey migrate, and cougars do not. we recorded 411 winter prey and 239 summer prey killed by 28 female and 10 male cougars, and an additional 37 prey items by unmarked cougars. deer composed 42.4% of summer cougar diets but only 7.2% of winter diets. males and females, however, selected different proportions of different prey; male cougars se ...201324349498
clinical, culture, serology, and histopathology outcomes of bighorn sheep experimentally infected with brucella ovis.disease caused by brucella ovis has not been previously reported in bighorn sheep (bhs; ovis canadensis canadensis). antibodies to b. ovis, however, are occasionally detected in free-ranging bhs, and this has been a concern for managers involved in translocation programs. to investigate the pathogenesis of b. ovis infection in this species, 20 bhs (10 male, 10 female) were inoculated intraconjunctivally (ic) with 5.4 × 10(8) colony forming units (cfu) b. ovis. six bhs (three male, three female) ...201324502717
in vitro prion protein conversion suggests risk of bighorn sheep (ovis canadensis) to transmissible spongiform encephalopathies.transmissible spongiform encephalopathies (tses) affect both domestic sheep (scrapie) and captive and free-ranging cervids (chronic wasting disease; cwd). the geographical range of bighorn sheep (ovis canadensis; bhs) overlaps with states or provinces that have contained scrapie-positive sheep or goats and areas with present epizootics of cwd in cervids. no tses have been documented in bhs, but the susceptibility of this species to tses remains unknown.201323938169
effective population size, genetic variation, and their relevance for conservation: the bighorn sheep in tiburon island and comparisons with managed artiodactyls.the amount of genetic diversity in a finite biological population mostly depends on the interactions among evolutionary forces and the effective population size (n(e)) as well as the time since population establishment. because the n(e) estimation helps to explore population demographic history, and allows one to predict the behavior of genetic diversity through time, n(e) is a key parameter for the genetic management of small and isolated populations. here, we explored an n(e)-based approach us ...201324147115
a quantitative trait locus analysis of personality in wild bighorn sheep.personality, the presence of persistent behav105ioral differences among individuals over time or contexts, potentially has important ecological and evolutionary consequences. however, a lack of knowledge about its genetic architecture limits our ability to understand its origin, evolution, and maintenance. here, we report on a genome-wide quantitative trait locus (qtl) analysis for two personality traits, docility and boldness, in free-living female bighorn sheep from ram mountain, alberta, cana ...201323531519
phylogenetic and epidemiologic relationships among pasteurellaceae from colorado bighorn sheep herds.we used 16s rrna sequencing and leukotoxin gene (lkta) screening via pcr assay to clarify phylogenetic and epidemiologic relationships among pasteurellaceae isolated from bighorn sheep (ovis canadensis). only six of 21 bighorn isolates identified as "mannheimia haemolytica" in original laboratory reports appeared to be isolates of m. haemolytica sensu stricto based on 16s rrna sequence comparisons; the remainder grouped with m. glucosida (n=8) or m. ruminalis (n=7). similarly, 16s rrna sequence ...201323778616
safety and immunogenicity of a mycoplasma ovipneumoniae bacterin for domestic sheep (ovis aries).mortality from epizootic pneumonia is hindering re-establishment of bighorn sheep populations in western north america. mycoplasma ovipneumoniae, a primary agent of this disease, is frequently carried asymptomatically by the domestic sheep and goats that constitute the reservoir of this agent for transmission to bighorn sheep. our long-term objective is to reduce the risk of m. ovipneumoniae infection of bighorn sheep; one approach to this objective is to control the pathogen in its reservoir ho ...201424752006
disease and predation: sorting out causes of a bighorn sheep (ovis canadensis) decline.estimating survival and documenting causes and timing of mortality events in neonate bighorn sheep (ovis canadensis) improves understanding of population ecology and factors influencing recruitment. during 2010-2012, we captured and radiocollared 74 neonates in the black hills, south dakota, of which 95% (70) died before 52 weeks of age. pneumonia (36%) was the leading cause of mortality followed by predation (30%). we used known fate analysis in program mark to estimate weekly survival rates an ...201424516623
epizootic pneumonia of bighorn sheep following experimental exposure to mycoplasma ovipneumoniae.bronchopneumonia is a population limiting disease of bighorn sheep (ovis canadensis). the cause of this disease has been a subject of debate. leukotoxin expressing mannheimia haemolytica and bibersteinia trehalosi produce acute pneumonia after experimental challenge but are infrequently isolated from animals in natural outbreaks. mycoplasma ovipneumoniae, epidemiologically implicated in naturally occurring outbreaks, has received little experimental evaluation as a primary agent of bighorn sheep ...201425302992
local extinction and unintentional rewilding of bighorn sheep (ovis canadensis) on a desert island.bighorn sheep (ovis canadensis) were not known to live on tiburón island, the largest island in the gulf of california and mexico, prior to the surprisingly successful introduction of 20 individuals as a conservation measure in 1975. today, a stable island population of ∼500 sheep supports limited big game hunting and restocking of depleted areas on the mexican mainland. we discovered fossil dung morphologically similar to that of bighorn sheep in a dung mat deposit from mojet cave, in the mount ...201424646515
pcr assay detects mannheimia haemolytica in culture-negative pneumonic lung tissues of bighorn sheep (ovis canadensis) from outbreaks in the western usa, 2009-2010.mannheimia haemolytica consistently causes severe bronchopneumonia and rapid death of bighorn sheep (ovis canadensis) under experimental conditions. however, bibersteinia trehalosi and pasteurella multocida have been isolated from pneumonic bighorn lung tissues more frequently than m. haemolytica by culture-based methods. we hypothesized that assays more sensitive than culture would detect m. haemolytica in pneumonic lung tissues more accurately. therefore, our first objective was to develop a p ...201424171569
blood values of captive beira antelope (dorcatragus megalotis) prior to and during an outbreak of fibrinous pleuropneumonia syndrome (fpps).currently the only captive population of beira antelope (dorcatragus megalotis) is held at the al wabra wildlife preservation, qatar. an outbreak of a severe respiratory disease--fibrinous pleuropneumonia syndrome, most likely caused by mycoplasma ovipneumoniae--led to a marked population decline. reactive systemic inflammatory (aa) amyloidosis was noted as a chronic manifestation of the disease. blood samples had been collected for biochemistry and hematology baseline values prior to the outbre ...201425632657
bighorn sheep × domestic sheep hybrids survive mannheimia haemolytica challenge in the absence of vaccination.bighorn sheep (bhs, ovis canadensis) are much more susceptible than domestic sheep (ds, ovis aries) to pneumonia caused by leukotoxin (lkt)-producing members of the family pasteurellaceae, particularly mannheimia haemolytica and bibersteinia trehalosi. leukotoxin is widely accepted as the critical virulence factor of these bacteria since lkt-negative mutants do not cause death of bhs. typically, ds carry lkt-positive m. haemolytica and/or b. trehalosi as commensal bacteria in their nasopharynx. ...201424629771
growth of mannheimia haemolytica: inhibitory agents and putative mechanism of inhibition.leukotoxin-producing mannheimia haemolytica consistently causes fatal pneumonia in bighorn sheep (bhs) under experimental conditions. surprisingly, by culture methods, it has been isolated from pneumonic bhs lungs less frequently than other bacteria. however, in one study pcr assays detected m. haemolytica from over 70% of the pneumonic lung samples that were negative for this organism by culture, suggesting that the growth of m. haemolytica is inhibited by other bacteria. previously, we have sh ...201425246231
a spatial risk assessment of bighorn sheep extirpation by grazing domestic sheep on public lands.bighorn sheep currently occupy just 30% of their historic distribution, and persist in populations less than 5% as abundant overall as their early 19th century counterparts. present-day recovery of bighorn sheep populations is in large part limited by periodic outbreaks of respiratory disease, which can be transmitted to bighorn sheep via contact with domestic sheep grazing in their vicinity. in order to assess the viability of bighorn sheep populations on the payette national forest (pnf) under ...201424507886
can phenotypic rescue from harvest refuges buffer wild sheep from selective hunting?human harvests can unwittingly drive evolution on morphology and life history, and these selective effects may be detrimental to the management of natural resources. although theory suggests that harvest refuges, as sources of unselected animals, could buffer the effects of human exploitation on wild populations, few studies have assessed their efficiency. we analyzed records from >7000 trophy bighorn rams (ovis canadensis) harvested in alberta, canada, between 1974 and 2011 to investigate if th ...201425535554
estimating genome-wide heterozygosity: effects of demographic history and marker type.heterozygosity-fitness correlations (hfcs) are often used to link individual genetic variation to differences in fitness. however, most studies examining hfcs find weak or no correlations. here, we derive broad theoretical predictions about how many loci are needed to adequately measure genomic heterozygosity assuming different levels of identity disequilibrium (id), a proxy for inbreeding. we then evaluate the expected ability to detect hfcs using an empirical data set of 200 microsatellites an ...201424149650
costs and benefits of group living with disease: a case study of pneumonia in bighorn lambs (ovis canadensis).group living facilitates pathogen transmission among social hosts, yet temporally stable host social organizations can actually limit transmission of some pathogens. when there are few between-subpopulation contacts for the duration of a disease event, transmission becomes localized to subpopulations. the number of per capita infectious contacts approaches the subpopulation size as pathogen infectiousness increases. here, we illustrate that this is the case during epidemics of highly infectious ...201425377464
demography, not inheritance, drives phenotypic change in hunted bighorn sheep.selective harvest, such as trophy hunting, can shift the distribution of a quantitative character such as body size. if the targeted character is heritable, then there will be an evolutionary response to selection, and where the trait is not, then any response will be plastic or demographic. identifying the relative contributions of these different mechanisms is a major challenge in wildlife conservation. new mathematical approaches can provide insight not previously available. here we develop a ...201425114219
sexually antagonistic association between paternal phenotype and offspring viability reinforces total selection on a sexually selected trait.the evolution of conspicuous sexually selected traits, such as horns or antlers, has fascinated biologists for more than a century. elaborate traits can only evolve if they substantially increase reproduction, because they probably incur survival costs to the bearer. total selection on these traits, however, includes sexual selection on sires and viability selection on offspring and can be influenced by changes in each of these components. non-random associations between paternal phenotype and o ...201424573156
comparing measures of breeding inequality and opportunity for selection with sexual selection on a quantitative character in bighorn rams.the reliability and consistency of the many measures proposed to quantify sexual selection have been questioned for decades. realized selection on quantitative characters measured by the selection differential i was approximated by metrics based on variance in breeding success, using either the opportunity for sexual selection is or indices of inequality. there is no consensus about which metric best approximates realized selection on sexual characters. recently, the opportunity for selection on ...201525418082
sex-based differences in the adaptive value of social behavior contrasted against morphology and environment.the adaptive nature of sociality has long been a central question in ecology and evolution. however, the relative importance of social behavior for fitness, compared to morphology and environment, remains largely unknown. we assessed the importance of sociality for fitness (lamb production and survival) in a population of mark6d bighorn sheep (ovis canadensis) over 16 years (n = 1022 sheep-years). we constructed social networks from observations (n = 38,350) of group membership (n = 3150 groups) ...201526236860
whole-genome resequencing uncovers molecular signatures of natural and sexual selection in wild bighorn sheep.the identification of genes influencing fitness is central to our understanding of the genetic basis of adaptation and how it shapes phenotypic variation in wild populations. here, we used whole-genome resequencing of wild rocky mountain bighorn sheep (ovis canadensis) to >50-fold coverage to identify 2.8 million single nucleotide polymorphisms (snps) and genomic regions bearing signatures of directional selection (i.e. selective sweeps). a comparison of snp diversity between the x chromosome an ...201526454263
evaluating distributional shifts in home range estimates.a variety of methods are commonly used to quantify animal home ranges using location data acquired with telemetry. high-volume location data from global positioning system (gps) technology provide researchers the opportunity to identify various intensities of use within home ranges, typically quantified through utilization distributions (uds). however, the wide range of variability evident within uds constructed with modern home range estimators is often overlooked or ignored during home range c ...201526445648
psoroptes infestation and treatment in an isolated population of bighorn sheep (ovis canadensis).the authors captured bighorn sheep (ovis canadensis) comprising a small population in the san bernardino mountains of california and evaluated the degree of infestation by mites of the genus psoroptes for each individual. the animals were treated with two novel methods: amitraz-impregnated collars and cyfluthrin-impregnated ear tags and recaptured the following year to evaluate the effect of treatment. the authors compared data on degree of infestation for animals recaptured in the posttreatment ...201526352952
comparison of modified flotac and baermann techniques for quantifying lungworm larvae in free-ranging bighorn sheep (ovis canadensis) feces, montana, usa.lungworms are important parasites of wildlife and host infection status is often evaluated using coprologic techniques, most commonly the baermann method. recently, the flotac® has emerged as a new tool for diagnosing lungworm infections, and methodologic comparison studies in domestic species suggest that this method outperforms many other established techniques. we compared a modified flotac with the beaker-modified (bm)-baermann to evaluate the relative performance of the two techniques for c ...201526267464
beyond mice and men: environmental change, immunity and infections in wild ungulates.in the face of rapid environmental change, anticipating shifts in microparasite and macroparasite dynamics, including emergence events, is an enormous challenge. we argue that immunological studies in natural populations are pivotal to meeting this challenge: many components of environmental change--shifts in biotic assemblages, altered climate patterns and reduced environmental predictability--may affect host immunity. we suggest that wild ungulates can serve as model systems aiding the discove ...201525354672
bighorn sheep (ovis canadensis) sinus tumors are associated with coinfections by potentially pathogenic bacteria in the upper respiratory tract.bighorn sheep (ovis canadensis) sinus tumors are hyperplastic to neoplastic, predominantly stromal masses of the paranasal sinuses that expand the sinus lining and obstruct the sinus cavities. obstruction of the sinus cavities and disruption of normal sinus lining anatomy may interfere with clearance of bacterial pathogens from the upper respiratory tract. to examine this possibility, we explored whether the presence of sinus tumor features (tumor score) affected the likelihood of detecting pote ...201525375938
phenotypic and molecular characterization of intrauterine fetal growth restriction in interspecies sheep pregnancy.interspecies pregnancies between closely related species are usually performed in livestock to obtain improved and enriched offspring. indeed, different hybrids have been obtained for research purposes since many years ago, and the maternal-fetal interactions have been studied as a possible strategy for species preservation. the aim of this study was to characterize by physiological and molecular approaches the interspecies pregnancy between bighorn sheep () and domestic sheep (). hybrids were o ...201526523562
beta-globin gene evolution in the ruminants: evidence for an ancient origin of sheep haplotype b.domestic sheep (ovis aries) can be divided into two groups with significantly different responses to hypoxic environments, determined by two allelic beta-globin haplotypes. haplotype a is very similar to the goat beta-globin locus, whereas haplotype b has a deletion spanning four globin genes, including beta-c globin, which encodes a globin with high oxygen affinity. we surveyed the beta-globin locus using resequencing data from 70 domestic sheep from 42 worldwide breeds and three ovis canadensi ...201526096044
acylation enhances, but is not required for, the cytotoxic activity of mannheimia haemolytica leukotoxin in bighorn sheep.mannheimia haemolytica causes pneumonia in domestic and wild ruminants. leukotoxin (lkt) is the most important virulence factor of the bacterium. it is encoded within the four-gene lktcabd operon: lkta encodes the structural protoxin, and lktc encodes a trans-acylase that adds fatty acid chains to internal lysine residues in the protoxin, which is then secreted from the cell by a type 1 secretion system apparatus encoded by lktb and lktd. it has been reported that lktc-mediated acylation is nece ...201526216418
harnessing cross-species alignment to discover snps and generate a draft genome sequence of a bighorn sheep (ovis canadensis).whole genome sequences (wgs) have proliferated as sequencing technology continues to improve and costs decline. while many wgs of model or domestic organisms have been produced, a growing number of non-model species are also being sequenced. in the absence of a reference, construction of a genome sequence necessitates de novo assembly which may be beyond the ability of many labs due to the large volumes of raw sequence data and extensive bioinformatics required. in contrast, the presence of a re ...201525990117
a chimeric protein comprising the immunogenic domains of mannheimia haemolytica leukotoxin and outer membrane protein plpe induces antibodies against leukotoxin and plpe.mannheimia haemolytica is a very important pathogen of pneumonia in ruminants. bighorn sheep (bhs, ovis canadensis) are highly susceptible to m. haemolytica-caused pneumonia which has significantly contributed to the drastic decline of bighorn sheep population in north america. pneumonia outbreaks in wild bhs can cause mortality as high as 90%. leukotoxin is the critical virulence factor of m. haemolytica. in a 'proof of concept' study, an experimental vaccine containing leukotoxin and surface a ...201627269790
evidence of bovine viral diarrhea virus infection in three species of sympatric wild ungulates in nevada: life history strategies may maintain endemic infections in wild populations.evidence for bovine viral diarrhea virus (bvdv) infection was detected in 2009-2010 while investigating a pneumonia die-off in rocky mountain bighorn sheep (ovis canadensis, canadensis), and sympatric mountain goats (oreamnos americanum) in adjacent mountain ranges in elko county, nevada. seroprevalence to bvdv-1 was 81% (n = 32) in the bighorns and 100% (n = 3) in the mountain goats. serosurveillance from 2011 to 2015 of surviving bighorns and mountain goats as well as sympatric mule deer (odoc ...201627014215
histophilosis as a natural disease.histophilus somni is responsible for sporadic disease worldwide in cattle and, to a lesser extent, in small ruminants, bighorn sheep (ovis canadensis), and north american bison (bison bison). the importance of h. somni diseases can be attributed to improved clinical and laboratory recognition, combined with the growth in intensive management practices for cattle. although outbreaks of bovine histophilosis can occur year-round, in northern and southern hemispheres, it is most frequent in late fal ...201626847357
genome sequence of bibersteinia trehalosi strain y31 isolated from the pneumonic lung of a bighorn sheep.here, we report the genome sequence for bibersteinia trehalosi strain y31, isolated from the lungs of a bighorn sheep (ovis canadensis) that had succumbed to pneumonia, which exhibits proximity-dependent inhibition (pdi) of mannheimia haemolytica the sequence will be used to understand the mechanism of pdi for these organisms.201627445392
role of carriers in the transmission of pneumonia in bighorn sheep (ovis canadensis).in the absence of livestock contact, recurring lamb mortality in bighorn sheep (ovis canadensis) populations previously exposed to pneumonia indicates the likely presence of carriers of pneumonia-causing pathogens, and possibly inadequate maternally derived immunity. to investigate this problem we commingled naïve, pregnant ewes (n=3) with previously exposed rams (n=2). post-commingling, all ewes and lambs born to them acquired pneumonia-causing pathogens (leukotoxin-producing pasteurellaceae an ...201627185269
potential foraging decisions by a desert ungulate to balance water and nutrient intake in a water-stressed environment.arid climates have unpredictable precipitation patterns, and wildlife managers often provide supplemental water to help desert ungulates endure the hottest, driest periods. when surface water is unavailable, the only source of water for ungulates comes from the forage they consume, and they must make resourceful foraging decisions to meet their requirements. we compared two desert bighorn sheep (ovis canadensis nelsoni) populations in arizona, usa: a treatment population with supplemental water ...201626894504
intense selective hunting leads to artificial evolution in horn size.the potential for selective harvests to induce rapid evolutionary change is an important question for conservation and evolutionary biology, with numerous biological, social and economic implications. we analyze 39 years of phenotypic data on horn size in bighorn sheep (ovis canadensis) subject to intense trophy hunting for 23 years, after which harvests nearly ceased. our analyses revealed a significant decline in genetic value for horn length of rams, consistent with an evolutionary response t ...201627099619
bartonella melophagi in blood of domestic sheep (ovis aries) and sheep keds (melophagus ovinus) from the southwestern us: cultures, genetic characterization, and ecological connections.bartonella melophagi sp. nov. was isolated from domestic sheep blood and from sheep keds (melophagus ovinus) from the southwestern united states. the sequence analyses of the reference strain performed by six molecular markers consistently demonstrated that b. melophagi relates to but differ from other bartonella species isolated from domestic and wild ruminants. presence of 183 genes specific for b. melophagi, being absent in genomes of other bartonella species associated with ruminants also su ...201627283855
fusobacterium necrophorum in north american bighorn sheep ( ovis canadensis ) pneumonia.fusobacterium necrophorum has been detected in pneumonic bighorn sheep (bhs; ovis canadensis ) lungs, in addition to the aerobic respiratory pathogens mannheimia haemolytica , bibersteinia trehalosi , pasteurella multocida , and mycoplasma ovipneumoniae . similar to m. haemolytica , f. necrophorum produces a leukotoxin. leukotoxin-induced lysis and degranulation of polymorphonuclear leukocytes (pmns) and macrophages are responsible for acute inflammation and lung tissue damage characteristic of ...201627224212
snp discovery in candidate adaptive genes using exon capture in a free-ranging alpine ungulate.identification of genes underlying genomic signatures of natural selection is key to understanding adaptation to local conditions. we used targeted resequencing to identify snp markers in 5321 candidate adaptive genes associated with known immunological, metabolic and growth functions in ovids and other ungulates. we selectively targeted 8161 exons in protein-coding and nearby 5' and 3' untranslated regions of chosen candidate genes. targeted sequences were taken from bighorn sheep (ovis canaden ...201627327375
large herbivores surf waves of green-up during spring.the green wave hypothesis (gwh) states that migrating animals should track or 'surf' high-quality forage at the leading edge of spring green-up. to index such high-quality forage, recent work proposed the instantaneous rate of green-up (irg), i.e. rate of change in the normalized difference vegetation index over time. despite this important advancement, no study has tested the assumption that herbivores select habitat patches at peak irg. we evaluated this assumption using step selection functio ...201627335416
differences in leukocyte differentiation molecule abundances on domestic sheep (ovis aries) and bighorn sheep (ovis canadensis) neutrophils identified by flow cytometry.although both domestic sheep (ds) and bighorn sheep (bhs) are affected by similar respiratory bacterial pathogens, experimental and field data indicate bhs are more susceptible to pneumonia. cross-reactive monoclonal antibodies (mabs) for use in flow cytometry (fc) are valuable reagents for interspecies comparative immune system analyses. this study describes cross-reactive mabs that recognize leukocyte differentiation molecules (ldms) and major histocompatibility complex antigens on ds and bhs ...201627260809
genome-wide set of snps reveals evidence for two glacial refugia and admixture from postglacial recolonization in an alpine ungulate.past glaciation events have played a major role in shaping the genetic diversity and distribution of wild sheep in north america. the advancement of glaciers can isolate populations in ice-free refugia, where they can survive until the recession of ice sheets. the major beringian refugium is thought to have held thinhorn sheep (ovis dalli) populations during times of glacial advance. while isolation in the major refugium can account for much of the genetic and morphological diversity seen in ext ...201627272944
experimental transmission of bighorn sheep sinus tumors to bighorn sheep (ovis canadensis canadensis) and domestic sheep.bighorn sheep sinus tumors are a recently described disease affecting the paranasal sinuses of rocky mountain bighorn sheep (ovis canadensis canadensis). several features of this disease suggest an infectious cause, although a specific etiologic agent has not been identified. to test the hypothesis that bighorn sheep sinus tumors are caused by an infectious agent, we inoculated 4 bighorn sheep lambs and 4 domestic sheep lambs intranasally with a cell-free filtrate derived from a naturally occurr ...201627020536
disease introduction is associated with a phase transition in bighorn sheep demographics.ecological theory suggests that pathogens are capable of regulating or limiting host population dynamics, and this relationship has been empirically established in several settings. however, although studies of childhood diseases were integral to the development of disease ecology, few studies show population limitation by a disease affecting juveniles. here, we present empirical evidence that disease in lambs constrains population growth in bighorn sheep (ovis canadensis) based on 45 years of p ...201627859120
an individual-based modelling approach to estimate landscape connectivity for bighorn sheep (ovis canadensis).background. preserving connectivity, or the ability of a landscape to support species movement, is among the most commonly recommended strategies to reduce the negative effects of climate change and human land use development on species. connectivity analyses have traditionally used a corridor-based approach and rely heavily on least cost path modeling and circuit theory to delineate corridors. individual-based models are gaining popularity as a potentially more ecologically realistic method of ...201627168997
horn and horn core trabecular bone of bighorn sheep rams absorbs impact energy and reduces brain cavity accelerations during high impact ramming of the skull.bighorn sheep (ovis canadensis) routinely experience violent impacts to the head as part of intraspecific fighting. dynamic 3d finite element models of the skull and horns of a male bighorn sheep were developed to gain an understanding of the roles that the horn and bone materials and structure play in absorbing the impact that occurs during ramming. the geometry and volume mesh of the model were derived from ct scan images. the models included the horn, bony horn core, and bone of the skull. th ...201627544811
demographic drivers of age-dependent sexual selection.sexual selection has a critical role in evolution, and it is fundamental to identify what ecological factors drive its variation. disentangling the ecological correlates of sexual selection over the long term, however, is challenging and has rarely been done in nature. we sought to assess how demographic changes influenced the intensity, direction and form of sexual selection and whether selective pressures varied with age. we tested whether breeder sex ratio, number of competitors and age struc ...201627090379
maternal condition and previous reproduction interact to affect offspring sex in a wild mammal.trivers and willard proposed that offspring sex ratio should vary with maternal condition when condition, meant as maternal capacity to care, has different fitness consequences for sons and daughters. in polygynous and dimorphic species, mothers in good condition should preferentially produce sons, whereas mothers in poor condition should produce more daughters. despite its logical appeal, support for this hypothesis has been inconsistent. sex-ratio variation may be influenced by additional fact ...201627512136
paternal reproductive success drives sex allocation in a wild mammal.parents should bias sex allocation toward offspring of the sex most likely to provide higher fitness returns. trivers and willard proposed that for polygynous mammals, females should adjust sex-ratio at conception or bias allocation of resources toward the most profitable sex, according to their own body condition. however, the possibility that mammalian fathers may influence sex allocation has seldom been considered. here, we show that the probability of having a son increased from 0.31 to 0.60 ...201626792564
phylogeographic and population genetic structure of bighorn sheep ( ovis canadensis ) in north american deserts.fossil data are ambiguous regarding the evolutionary origin of contemporary desert bighorn sheep ( ovis canadensis subspecies). to address this uncertainty, we conducted phylogeographic and population genetic analyses on bighorn sheep subspecies found in southwestern north america. we analyzed 515 base pairs of mtdna control region sequence and 39 microsatellites in 804 individuals from 58 locations. phylogenetic analyses revealed 2 highly divergent clades concordant with sierra nevada ( o. c. s ...201629899578
hierarchical structure and compressive deformation mechanisms of bighorn sheep (ovis canadensis) horn.bighorn sheep (ovis canadensis) rams hurl themselves at each other at speeds of ∼9 m/s (20 mph) to fight for dominance and mating rights. this necessitates impact resistance and energy absorption mechanisms, which stem from material-structure components in horns. in this study, the material hierarchical structure as well as correlations between the structure and mechanical properties are investigated. the major microstructural elements of horns are found as tubules and cell lamellae, which are o ...201728974475
age-specific infectious period shapes dynamics of pneumonia in bighorn sheep.superspreading, the phenomenon where a small proportion of individuals contribute disproportionately to new infections, has profound effects on disease dynamics. superspreading can arise through variation in contacts, infectiousness or infectious periods. the latter has received little attention, yet it drives the dynamics of many diseases of critical public health, livestock health and conservation concern. here, we present rare evidence of variation in infectious periods underlying a superspre ...201728871636
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