| prenatal infection of the rocky mountain bighorn sheep (ovis c. canadensis) of alberta with the lungworm protostrongylus spp. | first- and third-stage (infective) larvae of protostrongylus spp. were recovered from the livers of four fetuses of the rocky mountain bighorn sheep of alberta. this record suggests a more cosmopolitan distribution of prenatal infection with lungworms in bighorn sheep than suspected previously. | 1977 | 916136 |
| [nematodirinae (nematoda:trichostrongyloidea) of antilocapra and ovis in alberta, canada]. | in this first note, the trichostrongyloidea belonging to the nematodirinae parasites of ruminants from alberta are identified. new morphological data were given on nematodirella antilocaprae (price, 1927) parasite of antilocapra americana. nematodirus andersoni n. sp. is described from ovis canadensis. because of the deep indentation of the dorsal lobe, the species is similar to n. bioccai rossi, 1983 parasite of ovis aries in iran. however, it is different in the reduced number of cuticular rid ... | 1989 | 2624376 |
| sarcocystis in wild ungulates in alberta. | muscle samples from 557 wild ungulates in alberta, comprising seven species, were examined grossly and/or histologically for cysts of sarcocystis. sarcocystis was found in 100, 96, 94, 75, 75, 73, and 49% of the wapiti (cervus canadensis), moose (alces alces), bison (bison bison), mule deer (odocoileus hemionus), bighorn sheep (ovis canadensis), mountain goat (oreamnos americanus), and white-tailed deer (o. virginianus), respectively. | 1980 | 6780701 |
| selection and genetic (co)variance in bighorn sheep. | genetic theory predicts that directional selection should deplete additive genetic variance for traits closely related to fitness, and may favor the maintenance of alleles with antagonistically pleiotropic effects on fitness-related traits. trait heritability is therefore expected to decline with the degree of association with fitness, and some genetic correlations between selected traits are expected to be negative. here we demonstrate a negative relationship between trait heritability and asso ... | 2005 | 16050112 |
| geographic distribution of the muscle-dwelling nematode parelaphostrongylus odocoilei in north america, using molecular identification of first-stage larvae. | molecular identification of dorsal-spined larvae (dsl) from fecal samples indicates that the protostrongylid parasite parelaphostrongylus odocoilei occupies a broader geographic range in western north america than has been previously reported. we analyzed 2,124 fecal samples at 29 locations from thinhorn sheep (ovis dalli dalli and o. d. stonei), bighorn sheep (ovis canadensis canadensis and o. c. californiana), mountain goats (oreamnos americanus), woodland caribou (rangifer tarandus caribou), ... | 2005 | 16108550 |
| selection on heritable seasonal phenotypic plasticity of body mass. | the ability to cope with environmental change is fundamental to a species' evolution. organisms can respond to seasonal environmental variation through phenotypic plasticity. the substantial plasticity in body mass of temperate species has often been considered a simple consequence of change in environmental quality, but could also have evolved as an adaptation to seasonality. we investigated the genetic basis of, and selection acting on, seasonal plasticity in body mass for wild bighorn sheep e ... | 2007 | 17683438 |
| never too late? consequences of late birthdate for mass and survival of bighorn lambs. | in strongly seasonal environments, the timing of birth can have important fitness consequences. we investigated which factors affect parturition date and how birthdate interacts with sex, maternal characteristics and environmental variables to affect the growth and survival of bighorn sheep (ovis canadensis) lambs in a marked population in alberta. over 14 years, the estimated birthdate of 216 lambs ranged from 21 may to 18 july. parturition date was heritable and genetically correlated with mat ... | 2008 | 18443828 |
| 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 ... | 2012 | 22247368 |
| sheep-associated malignant catarrhal fever-like skin disease in a free-ranging bighorn sheep ( ovis canadensis ), alberta, canada. | malignant catarrhal fever-like clinical disease was diagnosed in a free-ranging bighorn sheep ( ovis canadensis ) from alberta, canada, in june 2015. antemortem and gross pathology findings included muscle atrophy, marked weight loss, and bilaterally symmetric alopecia with hyperpigmentation and crusting over the face, medial surfaces of the pinnae, dorsal trunk, distal limbs, perineal area, and tail. histologically, the skin lesions were characterized by granulomatous mural folliculitis with nu ... | 2017 | 27749194 |
| 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 ... | 2016 | 27090379 |