Distribution and abundance of terrestrial gastropods on a winter range of bighorn sheep in southwestern Alberta

1982 ◽  
Vol 60 (11) ◽  
pp. 2633-2640 ◽  
Author(s):  
D. A. Boag ◽  
W. D. Wishart
Keyword(s):  
Relative Abundance ◽  
Bighorn Sheep ◽  
Ovis Canadensis ◽  
The Other ◽  
Deciduous Tree ◽  
Annual Species ◽  
Vegetative Cover ◽  
Terrestrial Gastropods ◽  
Winter Range ◽  
Forested Areas

Living specimens of 15 species of terrestrial gastropods (14 snails and 1 slug) were collected on a series of plots located in a variety of habitats associated with a winter range of bighorn sheep (Ovis canadensis) in southwestern Alberta. Four species of snails (Vertigo gouldi, Discus cronkhitei, Vitrina alaskana, and Euconulus fulvus) constituted ca. 85% of all living specimens recorded in 1979, 1980, and 1981. However, the relative abundance of the last three species changed markedly between years. Based on the size of living individuals recovered over the snow-free season, only one snail (Vitrina alaskana) and the slug (Deroceras laeve) appeared to be annual species; the other common snails appear to live more than 1 year. The distribution of gastropods was correlated with the vegetative cover; maximum abundance was found within forested areas where deciduous tree or shrub growth was a major component of the canopy. The implications of the distribution and abundance of these molluscs for the transmission of lungworms to bighorn sheep is discussed.

Gastropod intermediate hosts of lungworms (Nematoda: Protostrongylidae) on a bighorn sheep winter range: aspects of transmission

1990 ◽  
Vol 68 (9) ◽  
pp. 1976-1982 ◽  
Author(s):  
L. A. Robb ◽  
W. M. Samuel
Keyword(s):  
Mule Deer ◽  
Bighorn Sheep ◽  
Ovis Canadensis ◽  
Intermediate Hosts ◽  
Gastropod Species ◽  
Winter Range ◽  
Infective Larvae ◽  
Third Stage ◽  
Inherent Problem

A study of the gastropod intermediate hosts of the lungworms Protostrongylus stilesi and Protostrongylus rushi was conducted on a bighorn sheep (Ovis canadensis canadensis) winter range in southwestern Alberta, 1984–1985. Over 7000 gastropods were examined. Seven gastropod species were infected with Protostrongylus-type larvae: the predominant intermediate hosts were Euconulus fulvus (6.8% infected), Vertigo gouldi (5.6%), and Vertigo modesta (3.2%). Prevalence of third-stage (infective) larvae was highest in September and April, coinciding with use of the winter range by bighorn sheep. An index of lungworm availability to sheep was highest in autumn in the margins of aspen copses and in spring in the grassy openings. Copses were used extensively by sheep in autumn, and open areas were used in the spring. Presence of a mule deer (Odocoileus h. hemionus) lungworm, Orthostrongylus macrotis, was an inherent problem.

scholarly journals Declines of Bighorn Sheep, Ovis canadensis, on Deteriorating Winter Range in Jasper National Park, Alberta, 1981-2010

2009 ◽  
Vol 123 (2) ◽  
pp. 157 ◽  
Author(s):  
Dick Dekker
Keyword(s):  
Cervus Elaphus ◽  
National Park ◽  
Full Range ◽  
Bighorn Sheep ◽  
Ovis Canadensis ◽  
Athabasca River ◽  
Jasper National Park ◽  
Winter Range ◽  
Salsola Kali ◽  
Average Annual Precipitation

Bighorn Sheep (Ovis canadensis) wintering in the lower Athabasca River valley of Jasper National Park, Alberta, were monitored from 1981 to 2010 by recording maximum band sizes per annum on two traditional but separate sheep ranges. In study area #1, the ram band declined significantly from a 20-year mean of 18 in the period 1981-2001 to a 5-year mean of 11 in the period 2001-2006, with a slight recovery in 2006-2010. Ewes in area #1 dwindled from a mean of 20 in the period 1981-1995 to zero in the period 1995-2010. In area #2, the ewe band dropped significantly from a mean of 40 in the period 1981-2001 to 24 in the period 2001-2010. The declines in area #1 coincided with an invasion of Russian Thistle (Salsola kali). Range conditions in area #2 deteriorated following four years with lower than average annual precipitation. The mean lamb:ewe ratio in area #2, pooled for 29 years, was 22:100 (n = 646). The sheep were protected from hunting, but were subject to a full range of indigenous carnivores. However, predation did not appear to be the primary cause of the declines, nor was competition for forage with American Elk (Cervus elaphus).

scholarly journals Brucellosis in Captive Rocky Mountain Bighorn Sheep (Ovis canadensis) Caused by Brucella abortus Biovar 4

2004 ◽  
Vol 40 (2) ◽  
pp. 311-315 ◽  
Author(s):  
Terry J. Kreeger ◽  
Walter E. Cook ◽  
William H. Edwards ◽  
Todd Cornish
Keyword(s):  
Brucella Abortus ◽  
Rocky Mountain ◽  
Bighorn Sheep ◽  
Ovis Canadensis

A survey of terrestrial gastropods from central Maine

1976 ◽  
Vol 54 (5) ◽  
pp. 620-627 ◽  
Author(s):  
J. George Gleich ◽  
Frederick F. Gilbert
Keyword(s):  
Relative Abundance ◽  
Habitat Preferences ◽  
Coniferous Forests ◽  
Snail Species ◽  
Forest Types ◽  
Mixed Forests ◽  
Terrestrial Gastropods

Terrestrial gastropods were collected in central Maine from June to November 1971 to study their distribution, relative abundance, and habitat preferences. Gastropods were widespread, but not abundant. Thirty-five percent of the 1626 gastropods collected were slugs. Thirty-seven snail species, including eight slug species, were found. Discus cronkhitei and Zonitoides arboreus were the most commonly collected gastropods: Deroceras reliculatum and Pallifera dorsalis were the most common slugs. Snails (excluding slugs) were more abundant in the northwestern portion of central Maine, whereas slugs were more abundant in the southeastern portion. Slugs were significantly less abundant in coniferous forests than in deciduous or mixed forests, but snail numbers (excluding slugs) in the three forest types were not significantly different.

In vitro measurements of the competitive interactions between two saprobic basidiomycetes on Typha latifolia

2005 ◽  
Vol 83 (11) ◽  
pp. 1523-1527 ◽  
Author(s):  
Michael J. Schulz ◽  
James F. Cahill, ◽  
Randolph S. Currah
Keyword(s):  
Relative Abundance ◽  
Typha Latifolia ◽  
The Other ◽  
Competitive Interactions ◽  
In Vitro Measurements ◽  
Leaf Tissues ◽  
Leaf Segments

Psathyrella typhae (Kalchbr.) Pearson & Dennis forms small basidiomata (mushrooms) and Sclerotium hydrophilum Saccardo in Rothert numerous minute sclerotia at the base of senescent shoots of Typha latifolia L. To assess how the two might compete in nature, isolates of these fungi were paired on autoclaved leaf segments of T. latifolia and incubated at 15 and 25 °C. The relative abundance of each species in the segments was determined by macerating the leaf tissues and then transferring fragments of macerate to microplates containing two types of media: one conclusively demonstrated the presence of P. typhae while the other demonstrated the presence of S. hydrophilum. Relative numbers of microplate wells showing positive reactions for each species on each medium indicated the proportion of the segment occupied following single and paired inoculations. These data demonstrated that competition was asymmetric, with P. typhae the stronger competitor at both temperatures, and uninhibited by the presence of S. hydrophilum. In contrast, S. hydrophilum was competitively excluded by P. typhae.

scholarly journals Desert Bighorn Sheep: Changes in Genetic Variation Over Time and the Impact of Merging Populations

2014 ◽  
Vol 5 (1) ◽  
pp. 3-13 ◽  
Author(s):  
Philip W. Hedrick ◽  
John D. Wehausen
Keyword(s):  
Genetic Variation ◽  
New Mexico ◽  
Monitoring And Evaluation ◽  
Bighorn Sheep ◽  
Ovis Canadensis ◽  
Mexican Population ◽  
Desert Bighorn Sheep ◽  
Two Generations ◽  
The Impact ◽  
Over Time

Abstract Founder effects, genetic bottlenecks, and genetic drift in general can lead to low levels of genetic diversity, which can influence the persistence of populations. We examine genetic variation in two populations of desert bighorn sheep Ovis canadensis from New Mexico and Mexico to measure change over time and evaluate the impact of introducing individuals from one population into the other. Over about three generations, the amount of genetic variation in the New Mexico population increased. In contrast, over about two generations the amount of genetic variation in the Mexican population decreased by a great extent compared with an estimate from another Mexican population from which it is primarily descended. The potential reasons for these changes are discussed. In addition, although both populations have low genetic variation, introduction of Mexican rams into the New Mexico population might increase the amount of genetic variation in the New Mexico population. Overall, it appears that management to increase genetic variation might require substantial detailed monitoring and evaluation of ancestry from the different sources and fitness components.

Factors influencing heart rate in free-ranging bighorn sheep: a physiological approach to the study of wildlife harassment

1979 ◽  
Vol 57 (10) ◽  
pp. 2010-2021 ◽  
Author(s):  
Robert A. MacArthur ◽  
Ronald H. Johnston ◽  
Valerius Geist
Keyword(s):  
Bighorn Sheep ◽  
Ovis Canadensis ◽  
Activity Level ◽  
Base Line ◽  
Vehicular Traffic ◽  
Behavioral Reactions ◽  
Factors Influencing ◽  
Close Range ◽  
Physiological Approach ◽  
Free Ranging

The telemetered heart rates (HR) of unrestrained female bighorn sheep (Ovis canadensis canadensis) were recorded under various behavioral and environmental circumstances. In all ewes HR varied positively with activity level and inversely with distance to a road traversing the study area. The HR recorded from animals moving at night or through timber by day were higher than during daytime movement across open slopes.Responses to transient stimuli varied greatly. The appearance of free-ranging canids evoked maximal increases in HR in all ewes. Vehicular traffic and aircraft elicited HR responses only at close range (< 200 m). Most (78.1%) HR responses to disturbing stimuli preceded or occurred in the absence of overt behavioral reactions. The HR usually peaked within 60 s of the onset of the response and recovered to predisturbance base line in less than 200 s. The appearance and continued presence (1–10 min) of a human within 50 m of the sheep resulted in a 20% rise in mean HR. The significance of these findings is discussed in relation to the behavior, ecology, and bioenergetics of bighorn sheep.

scholarly journals Differences in leukocyte differentiation molecule abundances on domestic sheep (Ovis aries) and bighorn sheep (Ovis canadensis) neutrophils identified by flow cytometry

2016 ◽  
Vol 46 ◽  
pp. 40-46 ◽  
Author(s):  
Margaret A. Highland ◽  
David A. Schneider ◽  
Stephen N. White ◽  
Sally A. Madsen-Bouterse ◽  
Donald P. Knowles ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Bighorn Sheep ◽  
Ovis Canadensis ◽  
Ovis Aries ◽  
Domestic Sheep
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