Reproductive success in female mountain goats

1991 ◽  
Vol 69 (12) ◽  
pp. 2956-2961 ◽  
Author(s):  
James A. Bailey
Keyword(s):  
Reproductive Success ◽  
Observational Studies ◽  
Rocky Mountain ◽  
Individual Characteristics ◽  
Extrinsic Factors ◽  
Oreamnos Americanus ◽  
Intrinsic Factors ◽  
Mountain Goats ◽  
Mountain Goat

Kid production by marked females, age ratios from a 24-year study, and the literature are used to evaluate hypotheses that three intrinsic and three extrinsic factors affect reproduction by female Rocky Mountain goats (Oreamnos americanus). On Sheep Mountain – Gladstone Ridge, Colorado, mountain goat age ratios declined while the herd grew during 1966–1979, and continued to decline with population stability during 1980–1989, suggesting a continued increase in ecological density of goats 39 years after they were introduced in 1950. Among intrinsic factors, age and persisting individual characteristics have influenced reproductive success of females. Reproductive success in any year has not limited success in the following year, except in 4-year-olds. Among extrinsic factors, reproductive success of female mountain goats has been negatively influenced by density or ecological density and by snowpack during gestation. Reproductive success of females may have been positively influenced by snowpack that enhanced forage conditions prior to breeding. The relative importance of these six factors in determining reproductive success of females may vary among and (temporally) within herds. Most hypotheses regarding reproductive success in female mountain goats remain poorly tested. Short-term observational studies hold little promise for testing hypotheses, owing to large among-years variation in reproductive success. Long-term, intensive observational studies, or manipulative experiments, are suggested.

scholarly journals Does reduced heterozygosity influence dispersal? A test using spatially structured populations in an alpine ungulate

2011 ◽  
Vol 7 (3) ◽  
pp. 433-435 ◽  
Author(s):  
Aaron B. A. Shafer ◽  
Jocelyn Poissant ◽  
Steeve D. Côté ◽  
David W. Coltman
Keyword(s):  
Population Monitoring ◽  
Structured Populations ◽  
Potential Cost ◽  
Opposite Pattern ◽  
Oreamnos Americanus ◽  
Long Term Study ◽  
Spatially Structured Populations ◽  
Mountain Goats ◽  
Mountain Goat

Despite having a profound effect on population dynamics, the reasons that animals disperse are poorly understood. Evolutionary explanations have focused on inbreeding and competition, where the potential cost of philopatry is negated through dispersal. Such scenarios lead to the prediction that less successful individuals preferentially disperse, termed ‘fitness-associated dispersal’. Since heterozygosity is associated with fitness, we assessed whether dispersed animals had less observed heterozygosity ( H O ) than residents. We tested this prediction using both genetic and population-monitoring data of mountain goats ( Oreamnos americanus ). Individuals classified as dispersers through cross-assignment had the lowest mean H O , followed by residents, and then admixed individuals. Dispersed individuals had 6.3 per cent less H O than their subpopulation of origin. In the long-term study of the mountain goat herd at Caw Ridge, Alberta, immigrants had the lowest H O ; however, the opposite pattern was seen in emigrants, which may be related to density dependence. This study is the first to provide empirical evidence that heterozygosity is associated with dispersal.

Glutathione peroxidase activity and selenium levels in Rocky Mountain bighorn sheep and mountain goats

1989 ◽  
Vol 67 (10) ◽  
pp. 2493-2496 ◽  
Author(s):  
Judith Samson ◽  
Jon T. Jorgenson ◽  
W. D. Wishart
Keyword(s):  
Glutathione Peroxidase ◽  
Clinical Signs ◽  
Rocky Mountain ◽  
Selenium Deficiency ◽  
Bighorn Sheep ◽  
Ovis Canadensis ◽  
Domestic Sheep ◽  
Oreamnos Americanus ◽  
Mountain Goats ◽  
Mountain Goat

Selenium levels and glutathione peroxidase (GSH-Px) activity were determined in the blood of wild and captive herds of bighorn sheep (Ovis canadensis), as well as in one wild mountain goat (Oreamnos americanus) herd. No significant relationship was established between blood selenium and GSH-Px activity for individual herds of bighorns, but when all herds were pooled, selenium was significantly (P < 0.01) correlated with GSH-Px. The hypothesis that bighorn sheep would exhibit higher GSH-Px activity per unit of blood selenium than domestic cattle was not supported. One bighorn population had blood selenium levels below those considered deficient in domestic sheep, yet exhibited no clinical signs of selenium deficiency. A blood selenium by GSH-Px relationship did not exist for the single mountain goat herd sampled. The seven blood samples collected from mountain goats did not differ from those from bighorn sheep in their GSH-Px activity relative to blood selenium levels.

scholarly journals Natural salt licks as a part of the ecology of the mountain goat

1971 ◽  
Vol 49 (5) ◽  
pp. 605-610 ◽  
Author(s):  
Daryl Hebert ◽  
I. McTaggart Cowan
Keyword(s):  
Sodium Intake ◽  
Rocky Mountain ◽  
Dry Weight ◽  
Sodium Content ◽  
Early Summer ◽  
Oreamnos Americanus ◽  
Low Sodium ◽  
Mountain Goats ◽  
Mountain Goat ◽  
Trench Area

Mountain goats (Oreamnos americanus) occupying the Rocky Mountain Trench area of southeastern British Columbia use natural earth licks in the spring (males) and early summer (females). Analysis of range vegetation reveals a low sodium content (mean about 0.004% dry weight). Despite low sodium intake from feed, blood sodium values were normal (m = 150.8 meq/liter). Loss of sodium via the fecal route increases abruptly in the spring. This period of increased loss corresponds with the lime of use of the natural licks. Mineral constituents of the licks were Ca (1050–85 000 ppm), P (0–25 ppm), and Na (115–5500 ppm). Each animal visited the lick but once during the summer and did so despite increased exposure to hazards of predation. Despite the low soil sodium content the inference is that the goats are eating the earth to compensate for Na deficiency.

Individual Variation in the Strength of Territory Defense in Male Song Sparrows: Correlates of Age, Territory Tenure, and Neighbor Aggressiveness

Behaviour ◽  
2004 ◽  
Vol 141 (1) ◽  
pp. 15-27 ◽  
Author(s):  
Jeremy Hyman ◽  
Melissa Hughes ◽  
Stephen Nowicki ◽  
William Searcy
Keyword(s):  
Individual Differences ◽  
Reproductive Success ◽  
Extrinsic Factors ◽  
Territory Defense ◽  
Intrinsic Factors ◽  
Territorial Aggression ◽  
Male Song ◽  
Song Sparrows ◽  
Territory Owner ◽  
Older Males

AbstractIn many species, the ability to defend a territory is essential for a male to obtain any reproductive success at all, and even among territorial individuals, variation in the strength of territory defense could have a significant impact on how much reproductive success is obtained. Previous studies have documented consistent individual differences in the vigor with which male song sparrows (Melospiza melodia) defend their territories, as measured by the strength of their reactions to territorial intrusions simulated through song playback. Variation in the strength of defense could reflect intrinsic differences among individuals in their resource holding potential (RHP), or variation in extrinsic factors. In this study, we examined whether variation in the strength of territory defense corresponds to differences in intrinsic factors such as the age or experience of the territory owner, the extrinsic factor of the level of aggression shown by neighbours, or both. Results indicate that males that previously held territories on the study site, regardless of whether they were holding the same territory as the previous year, show higher levels of territory defense than males that are new to the study site, and, assuming that returning males are older males, suggest that age is more important than experience on a specific territory in determining strength of territory defense. In addition, we found evidence that males with high levels of territorial aggression tend to be spatially clustered. The pattern observed suggests that a combination of intrinsic and extrinsic factors contribute to the expression of individual differences in territorial aggression.

Resource limitation in mountain goats: a test by experimental cropping

1988 ◽  
Vol 66 (1) ◽  
pp. 228-238 ◽  
Author(s):  
D. B. Houston ◽  
V. Stevens
Keyword(s):  
Population Dynamics ◽  
Density Dependence ◽  
National Park ◽  
Resource Limitation ◽  
Oreamnos Americanus ◽  
Olympic National Park ◽  
Fat Reserves ◽  
Goat Population ◽  
Mountain Goats ◽  
Mountain Goat

Changes are reported in the population dynamics and physical condition of mountain goats (Oreamnos americanus) following a reduction in their density at Olympic National Park, Washington, U.S.A. The goat population showed density-dependent responses in initial breeding ages and in litter size. Production and recruitment of kids were more variable at high densities, and these population attributes may show nonlinear density dependence. These shifts in dynamics were associated with increases in live weights and, possibly, in fat reserves. The density dependence shown was insufficient to compensate for removals that approximated the initial production of young, and goat numbers declined precipitously. The implications of these relationships to mountain goat ecology are examined.

Management and breeding of the Rocky Mountain goat Oreamnos americanus at Woodland Park Zoo

2007 ◽  
Vol 26 (1) ◽  
pp. 297-308 ◽  
Author(s):  
MICHAEL HUTCHINS ◽  
GREGG THOMPSON ◽  
BARBARA SLEEPER ◽  
JAMES W. FOSTER
Keyword(s):  
Rocky Mountain ◽  
Oreamnos Americanus ◽  
Mountain Goat

scholarly journals FatalCaprine arthritis encephalitis virus–like infection in 4 Rocky Mountain goats (Oreamnos americanus)

2012 ◽  
Vol 24 (2) ◽  
pp. 392-396 ◽  
Author(s):  
Kristin M. Patton ◽  
Robert J. Bildfell ◽  
Mark L. Anderson ◽  
Christopher K. Cebra ◽  
Beth A. Valentine
Keyword(s):  
Rocky Mountain ◽  
Encephalitis Virus ◽  
Oreamnos Americanus ◽  
Mountain Goats

scholarly journals Frequent Major Changing: Extrinsic and Intrinsic Factors

2008 ◽  
Vol 28 (2) ◽  
pp. 5-13 ◽  
Author(s):  
Michael W. Firmin ◽  
Lisa M. MacKillop
Keyword(s):  
Practice Theory ◽  
Research Practice ◽  
Structured Interviews ◽  
Extrinsic Factors ◽  
Intrinsic Factors ◽  
Personal Interests ◽  
Extrinsic And Intrinsic Factors ◽  
Lack Of Knowledge

Twenty undergraduates participated in individual, semi-structured interviews concerning their decisions to change majors. We found three common extrinsic and three intrinsic factors related to their decisions. Extrinsic factors included parents who were supportive but not meaningfully directive, lack of familial external guidance, and lack of knowledge concerning chosen majors and future careers. Intrinsic factors included students' difficulty making long-term decisions, desires for a major that meshed well with their personal interests, and satisfaction with majors that met those requirements. Relative Emphasis: research, practice, theory

Management and breeding of the Rocky Mountain goat Oreamnos americanus at Woodland Park Zoo

1986 ◽  
Vol 26 (1) ◽  
pp. 297-308
Author(s):  
MICHAEL HUTCHINS ◽  
GREGG THOMPSON ◽  
BARBARA SLEEPER ◽  
JAMES W. FOSTER
Keyword(s):  
Rocky Mountain ◽  
Oreamnos Americanus ◽  
Mountain Goat
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