Brucellosis in elk III. Serologic evaluation

The efficacy of the standard plate agglutination (SPT), buffered Brucella antigen rapid card (BBA), rivanol (Riv) and complement fixation (CFT) tests was statistically evaluated and correlated with known brucellosis infections in elk. Low titers on the SPT were detected in artificially exposed mature cow elk 2 weeks postinoculation and other tests began detecting antibodies at 3 weeks. Titers on all tests were detected as long as 4 years postinoculation. Serologic response was similar in artificially and naturally infected cows. Bulls did not maintain serologic titers as long as cows. The SPT at 1:25 or higher most frequently detected Brucella antibodies in infected elk, while the SPT at 1:100 or more least frequently detected antibodies. The percent of elk reacting at 1:100 or greater on the SPT declined rapidly after 6 months postinoculation. Combinations of any 2 of the 4 tests used had close agreement in concurrently identifying infected elk. The CFT correctly identified the greatest number (93%) of elk which were culture positive at necropsy and CFT titers persisted longer than those of the other tests. A CFT reaction persisted longer (average 10.7 weeks) than that of any other test in calves that demonstrated postnatal titers. The serologic responses of calves which acquired active infections were similar to adults. Criteria for identifying seropositive elk are discussed.     

Serological evidence of California serogroup virus activity in Oregon

We wished to demonstrate evidence of the presence of California serogroup viruses in Oregon and to test for the presence of certain other arboviruses in large ungulates. Blood samples from black-tailed deer (Odocoileus hemionus columbianus), mule deer (O. hemionus hemionus), and Roosevelt elk (Cervus elaphus roosevelti) from nine counties in Oregon were tested by serum-dilution plaque reduction neutralization for antibody to California serogroup viruses, including snowshoe hare, California encephalitis, and Jamestown Canyon, as well as to Cache Valley (Bunyamwera serogroup) and Klamath, an ungrouped rhabdovirus. Of 132 samples tested, 60 (46%) were found to be seropositive at a dilution of greater than or equal to 1:10 for at least one of the five different arboviruses. Forty (30%) samples contained antibody to more than one arbovirus, and 15 samples (11%) contained antibody to all five. Of these 15, 14 were from 75 black-tailed deer sera collected in Lincoln County, Oregon. Seropositivity rates for black-tailed deer ranged from 23% to 35%, with all five arboviruses represented. Positive reactions for all five arboviruses were represented among mule deer sera at rates from 5% to 29%. Elk sera were found to be positive for four of the viruses (none for Klamath virus). Although Cache Valley and Klamath viruses have been reported from Oregon, these data represent the first evidence of a California serogroup virus in the state.     

Prevalence of chronic wasting disease and bovine tuberculosis in free-ranging deer and elk in South Dakota

Heads of hunter-harvested deer and elk were collected throughout South Dakota (USA) and within established chronic wasting disease (CWD) surveillance areas from 1997-2002 to determine infection with CWD and bovine tuberculosis (TB). We used immunohistochemistry to detect CWD-infected individuals among 1,672 deer and elk sampled via geographically targeted surveillance. A total of 537 elk (Cervus elaphus nelsoni), 813 white-tailed deer (Odocoileus virginianus), and 322 mule deer (O. hemionus) was sampled for CWD. Estimated overall prevalence and associated confidence intervals (95%) in white-tailed deer was 0.001% (0-0.007%). Similarly, estimated overall prevalence in elk and mule deer was 0.0% (0-0.004%) and 0.0% (0-0.011%), respectively. A total of 401 elk, 1,638 white-tailed deer, and 207 mule deer was sampled for TB. Estimated overall prevalence of infection with TB in elk harvested in South Dakota was 0.0% (0-0.009%). Similarly, estimated overall prevalence of TB in white-tailed deer and mule deer harvested throughout South Dakota was 0.0% (0-0.002%) and 0.0% (0-0.018%), respectively.     

Mortality of Rocky Mountain elk in Michigan due to meningeal worm

Mortality from cerebrospinal parelaphostrongylosis caused by the meningeal worm (Parelaphostrongylus tenuis) has been hypothesized to limit elk (Cervus elaphus nelsoni) populations in areas where elk are conspecific with white-tailed deer (Odocoileus virginianus). Elk were reintroduced into Michigan (USA) in the early 1900s and subsequently greatly increased population size and distribution despite sympatric high-density (>or=12/km2) white-tailed deer populations. We monitored 100 radio-collared elk of all age and sex classes from 1981-94, during which time we documented 76 mortalities. Meningeal worm was a minor mortality factor for elk in Michigan and accounted for only 3% of mortalities, fewer than legal harvest (58%), illegal kills (22%), other diseases (7%), and malnutrition (4%). Across years, annual cause-specific mortality rates due to cerebrospinal parelaphostrongylosis were 0.033 (SE=0.006), 0.029 (SE=0.005), 0.000 (SE=0.000), and 0.000 (SE=0.000) for calves, 1-yr-old, 2-yr-old, and >or=3-yr-old, respectively. The overall population-level mortality rate due to cerebrospinal parelaphostrongylosis was 0.009 (SE=0.001). Thus, meningeal worm had little impact on elk in Michigan during our study despite greater than normal precipitation (favoring gastropods) and record (>or=14 km2) deer densities. Further, elk in Michigan have shown sustained population rates-of-increase of >or=18%/yr and among the highest levels of juvenile production and survival recorded for elk in North America, indicating that elk can persist in areas with meningeal worm at high levels of population productivity. It is likely that local ecologic characteristics among elk, white-tailed deer, and gastropods, and degree of exposure, age of elk, individual and population experience with meningeal worm, overall population vigor, and moisture determine the effects of meningeal worm on elk populations.     

Effects of Season and Scale on Response of Elk and Mule Deer to Habitat Manipulation

Abstract: Manipulation of forest habitat via mechanical thinning or prescribed fire has become increasingly common across western North America. Nevertheless, empirical research on effects of those activities on wildlife is limited, although prescribed fire in particular often is assumed to benefit large herbivores. We evaluated effects of season and spatial scale on response of Rocky Mountain elk (Cervus elaphus) and mule deer (Odocoileus hemionus) to experimental habitat manipulation at the Starkey Experimental Forest and Range in northeastern Oregon, USA. From 2001 to 2003, 26 densely stocked stands of true fir (Abies spp.) and Douglas-fir (Pseudotsuga menziesii) were thinned and burned whereas 27 similar stands were left untreated to serve as experimental controls. We used location data for elk and mule deer collected during spring (1 Apr-14 Jun) and summer (15 Jun-31 Aug) of 1999–2006 to compare use of treated and untreated stands and to model effects of environmental covariates on use of treated stands. In spring, elk selected burned stands and avoided control stands within the study area (second-order selection; large scale). Within home ranges (third-order selection; small scale), however, elk did not exhibit selection. In addition, selection of treatment stands by elk in spring was not strongly related to environmental covariates. Conversely, in summer elk selected control stands and either avoided or used burned stands proportional to their availability at the large scale; patterns of space use within home ranges were similar to those observed in spring. Use of treatment stands by elk in summer was related to topography, proximity to roads, stand size and shape, and presence of cattle, and a model of stand use explained 50% of variation in selection ratios. Patterns of stand use by mule deer did not change following habitat manipulation, and mule deer avoided or used all stand types proportional to their availability across seasons and scales. In systems similar to Starkey, manipulating forest habitat with prescribed fire might be of greater benefit to elk than mule deer where these species are sympatric, and thus maintaining a mixture of burned and unburned (late successional) habitat might provide better long-term foraging opportunities for both species than would burning a large proportion of a landscape.     

Prevalence of antibodies to Neospora caninum in white-tailed deer,Odocoileus virginianus,from the southeastern United States

Serum samples from 305 white-tailed deer (Odocoileus virginianus) from 14 states in the southeastern United States were examined for antibodies to Neospora caninum using a direct agglutination test. Positive agglutination titers were found in 145 (48%) of the white-tailed deer examined: 21 (7%) had titers of 1:25, 92 (30%) had titers of 1:50, and 32 (10%) had titers of > or = 1:500. These findings that antibodies to N. caninum are common in white-tailed deer support the concept that a sylvatic cycle might exist for this economically important parasite of domestic cattle.     

Two Theileria cervi SSU RRNA gene sequence types found in isolates from white-tailed deer and elk in North America.

Two Theileria cervi SSU rRNA gene sequence Types, F and G, from white-tailed deer (Odocoileus virginianus) and elk (Cervus elaphus canadensis) isolates in North America were confirmed. Previously, nucleotide sequencing through a single variable (V4) region showed the presence of SSU rRNA gene Types F and G in T. cervi isolates from white-tailed deer and an elk. In this study, both sequence types were found in four T. cervi isolates (two from deer and two from elk). Microheterogeneity only appeared in the Type G gene, resulting in Subtypes G1, G2 and G3. Subtype G1 was found in two elk and one white-tailed deer T. cervi isolate; Subtypes G2 and G3 were found in a white-tailed deer T. cervi isolate. The Type F SSU rRNA genes were identical in nucleotide sequence in both elk and white-tailed deer T. cervi isolates. The high degree of conservation in the Type F variable regions may be exploited to design specific oligonucleotide primers for parasite detection by the polymerase chain reaction in cervine or tick hosts.     

Epizootiology of chronic wasting disease in free-ranging cervids in Colorado and Wyoming

Surveillance and epidemic modeling were used to study chronic wasting disease (CWD), a transmissible spongiform encephalopathy that occurs naturally among sympatric, free-ranging deer (Odocoileus spp.) and Rocky Mountain elk (Cervus elaphus nelsoni) populations in contiguous portions of northeastern Colorado and southeastern Wyoming (USA). We used clinical case submissions to identify endemic areas, then used immunohistochemistry to detect CWD-infected individuals among 5,513 deer and elk sampled via geographically-focused random surveys. Estimated overall prevalence (prevalence, 95% confidence interval) in mule deer (4.9%, 4.1 to 5.7%) was higher than in white-tailed deer (2.1%, 0.5 to 3.4%) or elk (0.5%, 0.001 to 1%) in endemic areas; CWD was not detected in outlying portions of either state. Within species, CWD prevalence varied widely among biologically- or geographically-segregated subpopulations within the 38,137 km2 endemic area but appeared stable over a 3-yr period. The number of clinical CWD cases submitted from an area was a poor predictor of local CWD prevalence, and prevalence was typically > or =1% before clinical cases were first detected in most areas. Under plausible transmission assumptions that mimicked field data, prevalence in epidemic models reached about 1% in 15 to 20 yr and about 15% in 37 to 50 yr. Models forecast population declines once prevalence exceeded about 5%. Both field and model data supported the importance of lateral transmission in CWD dynamics. Based on prevalence, spatial distribution, and modeling, we suggest CWD has been occurring in northeastern Colorado and southeastern Wyoming for >30 yr, and may be best represented as an epizootic with a protracted time-scale.     

Experimental oral transmission of chronic wasting disease to reindeer (Rangifer tarandus tarandus)

Chronic wasting disease (CWD), a transmissible spongiform encephalopathy of cervids, remains prevalent in North American elk, white-tailed deer and mule deer. A natural case of CWD in reindeer (Rangifer tarandus tarandus) has not been reported despite potential habitat overlap with CWD-infected deer or elk herds. This study investigates the experimental transmission of CWD from elk or white-tailed deer to reindeer by the oral route of inoculation. Ante-mortem testing of the three reindeer exposed to CWD from white-tailed deer identified the accumulation of pathological PrP (PrP(CWD)) in the recto-anal mucosa associated lymphoid tissue (RAMALT) of two reindeer at 13.4 months post-inoculation. Terminal CWD occurred in the two RAMALT-positive reindeer at 18.5 and 20 months post-inoculation while one other reindeer in the white-tailed deer CWD inoculum group and none of the 3 reindeer exposed to elk CWD developed disease. Tissue distribution analysis of PrP(CWD) in CWD-affected reindeer revealed widespread deposition in central and peripheral nervous systems, lymphoreticular tissues, the gastrointestinal tract, neuroendocrine tissues and cardiac muscle. Analysis of prion protein gene (PRNP) sequences in the 6 reindeer identified polymorphisms at residues 2 (V/M), 129 (G/S), 138 (S/N) and 169 (V/M). These findings demonstrate that (i) a sub-population of reindeer are susceptible to CWD by oral inoculation implicating the potential for transmission to other Rangifer species, and (ii) certain reindeer PRNP polymorphisms may be protective against CWD infection.     

Factors associated with use of wildlife underpasses and importance of long-term monitoring

We evaluated use of 6 wildlife underpasses (UP) using video camera surveillance along State Route 260 in Arizona, USA. We documented wildlife use and compared successful UP crossings by various species and among UP. From 2002 to 2008, we recorded visits by 15,134 animals of 21 species (16 wildlife, 5 domestic) resulting in 72.4% crossing through UP. Elk (Cervus elaphus) accounted for 68% of recorded animals, white-tailed deer (Odocoileus virginianus) and mule deer (O. hemionus) accounted for 13% and 6%, respectively. As elk and white-tailed deer were the only species adequately represented across all UP, we used logistic regression to further evaluate factors associated with successful use of UP. To evaluate habituation over time we limited this analysis to 5 UP monitored for ≥4 yr. For elk, structural attributes and placement, season, time of day, and months monitored were associated with successful elk UP crossing in year 1, however, by year 4 only structural attributes and placement were significant, suggesting that UP structure and placement likely were of primary importance for successful elk passage. By year 4, probabilities of crossing at 4 of 5 UP converged on >0.70, indicating that given sufficient time to allow habituation, most UP we evaluated appeared to be effective for elk, regardless of structural attributes or placement. For deer, only structural attribute and placement were significant, and aside from one structure did not increase in probability of a successful crossing over time. The overall number of animals and species that crossed SR 260 via UP underscores efficacy of UP in promoting multi-species permeability. Long-term monitoring allows wildlife and highway managers to evaluate adaptation to wildlife crossing structures by different species. Results from this study add to our knowledge of mitigating the impact of highways on wildlife. © 2011 The Wildlife Society.     

Condition of mule deer during winter: stress and spatial overlap with North American elk

We assessed body condition, diet quality (indexed by fecal nitrogen), and stress levels (using fecal glucocorticoid metabolites) in mule deer Odocoileus hemionus in southeastern Idaho, USA, during a mild (2007) and a harsh winter (2008) to evaluate spatial overlap and potential competition with North American elk Cervus elaphus. We used data from GPS telemetry to construct spatially explicit maps of local population density of elk for January–April. Loss of body condition over winter in yearling and adult female mule deer was not related to elk density but to winter severity. Fecal nitrogen increased as winter progressed in both winters, was significantly lower during 2008 than in 2007, but was not related to local population density of elk. In the mild winter of 2007, a significant positive relationship existed between local population density of elk and fecal glucocorticoid metabolite levels of mule deer, indicating increased physiological stress among mule deer wintering in close proximity to elk. Fecal glucocorticoid metabolite levels in deer were lower in 2008 than in 2007 and exhibited no significant relationship with elk density. Declining fecal glucocorticoid levels through winter may be typical of northern cervids. No difference existed in levels of fecal glucocorticoids between sexes of deer. A reduction in elk populations may not improve diet quality, physiological stress levels, or body condition of mule deer on winter range, especially during severe winters. Consequently, management and conservation of winter habitat are more likely to benefit mule deer than would altering density of elk.     

Estimating the true prevalence of Mycobacterium bovis in free-ranging elk in Michigan

Although relatively small, Michigan's elk (Cervus elaphus nelsoni) herd is highly valued by both hunters and the general public. Elk and red deer (Cervus elaphus elaphus) are highly susceptible to infection with Mycobacterium bovis, the causative agent of bovine tuberculosis (TB), and outbreaks have been documented worldwide. The Michigan elk range lies entirely within counties where TB is known to be enzootic in white-tailed deer (Odocoileus virginianus). Consequently, a project was undertaken to estimate the true prevalence of TB in Michigan's free-ranging elk herd. All elk harvested by licensed hunters during 2002-2004, and all nonharvest elk mortalities examined by the Michigan Department of Natural Resources Wildlife Disease Laboratory from November 2002-May 2005, were screened for gross lesions of TB with samples of cranial lymph nodes and palatine tonsils collected for histopathology and mycobacterial culture. In all, 334 elk were included in the study. Twenty-three elk with gross lesions were considered TB suspects; all were culture-negative for M. bovis. However, M. bovis was cultured from two elk without gross lesions. The sensitivity, specificity, and negative predictive value of the current TB surveillance protocol were 0%, 100%, and 99.4%, respectively, while the apparent prevalence and true prevalence calculated directly from the sample were 0% and 0.6%, respectively. The positive predictive value and the estimated true prevalence of the population were undefined. The poor sensitivity of current surveillance was likely an artifact of its application to a relatively small sample, in order to detect a disease present at very low prevalence. The low prevalence of TB in Michigan elk, and the early stage of pathogenesis of the few infected animals, does not suggest elk are maintenance hosts at the present time.     

Differential prey use by male and female cougars in Washington

Male and female predators are often assumed to have the same effects on prey. Because of differences in body size and behavior, however, male and female predators may use different species, sexes, and ages of prey, which could have important implications for wildlife conservation and management. We tested for differential prey use by male and female cougars (Puma concolor) from 2003 to 2008 in Washington State. We predicted that male cougars would kill a greater proportion of larger and older prey (i.e., adult elk [Cervus elaphus]), whereas females would kill smaller and younger prey (i.e., elk calves, mule deer [Odocoileus hemionus]). We marked cougars with Global Positioning System (GPS) radio collars and investigated 436 predation sites. We located prey remains at 345 sites from 9 male and 9 female cougars. We detected 184 mule deer, 142 elk, and 17 remains from 4 other species. We used log-linear modeling to detect differences in species and age of prey killed among cougar reproductive classes. Solitary females and females with dependent offspring killed more mule deer than elk (143 vs. 83, P < 0.01), whereas males killed more elk than mule deer (59 vs. 41, P < 0.01). Proportionately, males killed 4 times more adult elk than did females (24% vs. 6% of kills) and females killed 2 times more adult mule deer than did males (26% vs. 15% of kills). Managers should consider the effects of sex of predator in conservation and management of ungulates, particularly when managing for sensitive species. © 2011 The Wildlife Society.     

Winter predation patterns of wolves in Northwestern Wyoming

Wolf (Canis lupus) diets and potential effects on prey have been a prominent subject of interest to wildlife researchers and managers since reintroduction into Yellowstone National Park, Wyoming, USA, in 1995 and 1996. Post-reintroduction, wolves expanded south and recolonized areas in the southern Yellowstone ecosystem. Elk (Cervus elaphus) in this area are supplementally fed during winter (Dec–Mar) at state-managed feedgrounds, resulting in high-density congregations of elk. From December to March 2000–2007, we determined the winter predation patterns of wolves by examining the remains of 289 wolf kills on 3 state-managed feedgrounds and adjacent winter range near Jackson, Wyoming. During winters 2002–2005, we also monitored the movements of radio-collared elk on feedgrounds to describe the response of elk to the presence of wolf kills. Thirty-seven percent (n = 106) of kills were located on elk feedgrounds where elk composition included 49% calves, 42% adult females, 5% adult males, and 5% unknown. Sixty-three percent (n = 183) of kills were located on winter range adjacent to feedgrounds and prey species consisted of 90% elk (38% calves, 35% adult females, 24% adult males, 2% unknown), 9% moose (Alces alces; 13% calves, 69% adult females, 6% adult males, 1% unknown), 1% mule deer (Odocoileus hemionus; 1 fawn, 1 adult female), and 0.5% adult female bison (Bison bison). Mean age of elk killed on feedgrounds was 4.2 years (range = 0–20) and 4.6 years (range = 0–23) on winter range. Calves were selected more than available in most years with female elk killed less than expected. Adult males were killed more than expected in 2005–2007. Eighty-eight percent (n = 198) of the time elk remained on the feedground even when wolves made a kill. Less commonly, elk left the feedground, gathered in larger herds on adjacent feedgrounds absent of wolves, and returned within a few days (6%, n = 13) or left the feedground for another feedground and did not return for the rest of the winter (6%; n = 14). Elk were less likely to leave feedgrounds in the presence of a wolf kill when there were more elk on that feedground. Elk left feedgrounds with greater topography and tree cover (Alkali and Fish Creek) and gathered on the flat, open feedgrounds (Patrol Cabin) more frequently than they left flat, open feedgrounds for feedgrounds with greater topography and tree cover. Our results indicate wolves in our study area primarily preyed on elk and exhibited a strong preference for elk calves. High-density concentrations of elk on feedgrounds will continue to be an attractant for wolves. Although elk leave feedgrounds for reasons other than wolf presence, any displacement of elk from feedgrounds due to wolves will be temporary. State managers have the ability to alter management strategies (e.g., increasing wolf harvest, phasing out elk feeding, increasing the intensity of elk feeding) in an effort to affect predator-prey relationships. © 2019 The Wildlife Society.     

Cervids with different vocal behavior demonstrate different viscoelastic properties of their vocal folds

The authors test the hypothesis that vocal fold morphology and biomechanical properties covary with species‐specific vocal function. They investigate mule deer (Odocoileus hemionus) vocal folds, building on, and extending data on a related cervid, the Rocky Mountain elk (Cervus elaphus nelsoni). The mule deer, in contrast to the elk, is a species with relatively little vocal activity in adult animals. Mule deer and elk vocal folds show the typical three components of the mammalian vocal fold (epithelium, lamina propria and thyroarytenoid muscle). The vocal fold epithelium and the lamina propria were investigated in two sets of tensile tests. First, creep rupture tests demonstrated that ultimate stress in mule deer lamina propria is of the same magnitude as in elk. Second, cyclic loading tests revealed similar elastic moduli for the vocal fold epithelium in mule deer and elk. The elastic modulus of the lamina propria is also similar between the two species in the low‐strain region, but differs at strains larger than 0.3. Sex differences in the stress–strain response, which have been reported for elk and human vocal folds, were not found for mule deer vocal folds. The laminae propriae in mule deer and elk vocal folds are comparatively large. In general, a thick and uniformly stiff lamina propria does not self‐oscillate well, even when high subglottic pressure is applied. If the less stiff vocal fold seen in elk is associated with a differentiated lamina propria it would allow the vocal fold to vibrate at high tension and high subglottic pressure. The results of this study support the hypothesis that viscoelastic properties of vocal folds varies with function and vocal behavior. J. Morphol., 2010. © 2009 Wiley‐Liss, Inc.     

Influence of Landscape Characteristics on Hunter Space Use and Success

Sport hunting of ungulates is a predominant recreational pursuit and the primary tool for managing their populations in North America and beyond, given its influence on ungulate distributions, social organization, and population performance. Similarly, land management, such as motorized vehicle access, influences ungulate distributions during and outside hunting seasons. Although research on ungulate responses to hunting and land use is widespread, knowledge gaps persist about space use of hunters and what landscape features discriminate among hunt types and between successful and unsuccessful hunters. We used telemetry location data from hunters (n = 341) to estimate space use from 2008–2013 during 3 types of controlled, 5-day hunts for antlered mule deer (Odocoileus hemionus) and elk (Cervus canadensis) in northeastern Oregon, USA: archery elk, rifle deer, and rifle elk. To evaluate space use, we developed utilization distributions for each hunter, created core areas (50% contours) for groups of hunters, and derived several metrics of space-use overlap between successful and unsuccessful hunters. We also modeled predictors of space use using resource utilization functions with beta regression and stepwise model building. Hunter space use was compressed, with even the largest core area (unsuccessful rifle elk hunters) encompassing <16% (1,178 ha) of the area. We found strong similarities in space use of rifle hunters compared to archers, and core areas of successful hunters were markedly smaller than those of unsuccessful hunters (e.g., = 104 ha vs. 681 ha, respectively, for archers). Percentage cover and distance from open roads were the most consistent covariates in the 6 final models (successful vs. unsuccessful for each of 3 hunts) but with different signs. For example, predicted use of archery and rifle elk hunters increased with cover but decreased for rifle deer hunters. Although the same covariates were in the final models for unsuccessful and successful rifle elk hunters, their negligible spatial overlap suggested they sought those features in different locales, a pattern also documented for rifle deer hunters. Our models performed well (Spearman's rank correlation coefficients = 0.99 for 5 of 6 models), reflecting their utility for managing hunters and landscapes. Our results suggest that strategic management of open roads and forest cover can benefit managers seeking to balance hunter opportunity and satisfaction with harvest objectives, especially for species of special concern such as mule deer, and that differences in space use among hunter groups should be accounted for in hunting season designs. © 2021 The Wildlife Society. This article has been contributed to by US Government employees and their work is in the public domain in the USA.     

Experimental infection of some North American wild ruminants and domestic sheep with Mycobacterium paratuberculosis: clinical and bacteriological findings

Mycobacterium paratuberculosis originally isolated from bighorn sheep (Ovis canadensis) with spontaneous paratuberculosis was used to orally inoculate Rocky Mountain elk (Cervus elaphus nelsoni) calves, mule deer (Odocoileus hemionus) fawns, white-tailed deer (Odocoileus virginianus) fawns, bighorn X mouflon (Ovis musimon) hybrid lambs, and domestic lambs. All experimentally exposed animals became infected. During the first year of infection, hybrid and domestic sheep were able to control the infection but infection was progressive in elk and deer. Clinical paratuberculosis occurred only in mule deer.     

Serosurvey for selected infectious disease agents in free-ranging black and white rhinoceros in Africa

Two hundred and eighty one serum samples collected from free-ranging black (Diceros bicornis) and white (Ceratotherium simum) rhinoceros, in the Republic of South Africa (RSA), Namibia, and Kenya from 1987-97, were examined for antibody to 16 different infectious agents. Positive antibody titers were detected against Akabane (59.8%), bluetongue (55%), African horse sickness (27.9%), epizootic haemorrhagic disease of deer (19.4%), parainfluenza type 3 (25.3%), bovine herpes virus 1 (3.1%), equine herpes virus 1 (8.8%) and bovine viral diarrhea (1.2%) viruses, and four serovars of Leptospira interrogans, (ranging 1.2 to 8.8%). No antibody was detected against Rift Valley fever virus, encephalomyocarditis virus, Brucella abortus, and Trypanosoma equiperdum. Interspecies differences were detected for African horse sickness, epizootic haemorrhagic disease of deer and parainfluenza type 3 viruses. There appeared to be some geographic variation in the prevalence of antibody for African horse sickness, bluetongue, epizootic haemorrhagic disease of deer, parainfluenza type 3, equine herpes virus 1 and Leptospira interrogans serovar bratislava.     

Mineral deficiencies in tule elk, Owens Valley, California

Male tule elk (Cervus elaphus nannodes) are susceptible to high rates of antler breakage in Owens Valley, California. We hypothesized that a mineral deficiency in the diet predisposed male elk to antler breakage. We analyzed elk antler, liver, and forage samples to identify mineral imbalances. We compared the mineral content of livers and antlers from elk in Owens Valley to samples taken from tule elk at Grizzly Island Wildlife Area, a population experiencing normal rates (<5%) of antler breakage. Antler and liver samples were collected from 1989 to 1993, and in 2002, and were tested for calcium (Ca), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), molybdenum (Mo), phosphorus (P), sulfur (S), and zinc (Zn). Mineral levels from antler and liver samples were compared to reference values established for elk and deer. We also compared the mineral content of elk forage in Owens Valley, collected in 2002-03, to dietary reference values established for cattle. In antlers, Ca, Fe, and Mg levels were higher in Owens Valley elk than in Grizzly Island elk, although all mineral levels were lower than reference values established for deer antlers. In liver samples, Cu levels from elk in Owens Valley were lower than those from Grizzly Island and lower than minimum reference values; liver Ca and Mo levels were higher in elk from Owens Valley than in those from Grizzly Island. Compared to reference values, elk forage in Owens Valley had high levels of Ca and Mo, and low levels of Cu, P, and Zn. Mineral analyses from antlers, livers, and forage suggest that tule elk in the Owens Valley are Cu and/or P deficient. High levels of Mo and Ca may exacerbate Cu and P deficiencies, respectively. Bone fragility is a symptom of both deficiencies, and an imbalance in Cu, P, or a combination of both, may predispose male tule elk in the Owens Valley to antler breakage.     

Antibodies to granulocytic Ehrlichia in moose, red deer, and roe deer in Norway

Serum samples from 104 moose (Alces alces), 124 red deer (Cervus elaphus) and 114 roe deer (Capreolus capreolus), collected from different counties in southern Norway from 1994 to 2000, were analysed by an indirect immunofluorescent antibody staining method for antibodies to Ehrlichia equi. The overall seroprevalences for granulocytic Ehrlichia spp. in moose, red deer, and roe deer from Ixodes ricinus infested counties were 43%, 55%, and 96%, respectively. Antibody prevalence was significantly higher in roe deer than in moose and red deer (P < 0.001). Mean antibody titers (log10 +/- SD) to E. equi in sera from moose, red deer, and roe deer were 1:1,497 (3.17 +/- 0.646), 1:234 (2.37 +/- 0.424) and 1:676 (2.83 +/- 0.404), respectively. The present work indicates that all these wild ruminant species are exposed to granulocytic Ehrlichia in Norway.