Life Sciences Commons^™

Vulnerability Of Cougars To Hunting, Dan Barnhurst

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Forty radio-collared cougars (Felis concolor) were monitored for 630 cougar months. Track searches were conducted and tracking information was gathered over a 20-month period. Vulnerability was estimated to be greatest for 0 to 6-month-old kittens. This age class is the most susceptible to starvation after being orphaned, or being killed by hounds when the hunter is unaware of their presence, since their tracks were found with their mother's tracks only 19 percent of the time. Tracks of 7 to 12-month old kittens were found with their mother's tracks 43 percent of the time. Relative road-crossing frequencies of seven …

Manganese Toxicity In Mice: Evaluation Of Neruochemical And Immunologial Alteration, Benjamart Srisuchart

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Neurochemical and immunological effects of manganese chloride (MnCl₂) were evaluated using young male CD-1 mice as the animal model. Intraperitoneal (i.p.) injection of MnCl₂ (1, 3 and 10 mg/kg) daily for 4 weeks did not produce mortality or overt signs of toxicity in any of the treated animals. Manganese treatment increased the thymidine uptake of cultured splenic cells and the selective lymphoproliferative response to T-cell mitogens, phytohaemagglutinin and concanavalin A, in all the treated groups. No difference in the response to B-cell mitogen, lipopolysaccharide was observed. A dose of 10 mg/kg MnCl₂ increased the mixed lymphocyte …

Effect Of Spring Grazing By Cattle On Growth And Survival Of Shrub Seedlings Interplanted In Crested Wheatgrass, Lynn M. Mcconville

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A short duration-high intensity grazing trial was conducted in spring of 1985 to determine whether shrub establishment in crested wheatgrass pastures could be enhanced through spring grazing by cattle, or by fertilization of shrub seedlings. Data was collected on diet selection by cattle during spring grazing, and on subsequent shrub growth and survival. Shrubs studied were transplants of sagebrush, Artemisia tridentata, fourwing saltbush, Atriplex canescens, bitterbrush, Purshia tridentata, and one year old bitterbrush seedlings.

Cattle did not browse sagebrush or fourwing saltbush transplants, but utilization of bitterbrush transplants and seedlings averaged 15 and 42 percent, respectively. Shrub …

Factors Affecting Puberty, Estrus And Ovulation In Corriedale And Criollo Sheep Of The Southern Peruvian Highlands, Pedro Walter Bravo Matheus

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research was conducted at the La Raya experiment station, Cusco, Peru (4200 m elevation, 15°S latitude, and 70 °W longitude) using 60 Corriedale, and 60 Criollo ewes during three consecutive years (April 1981 - March 1984). Age, and weight at puberty, age at physical maturity, and the effects of breed, age (physically immature and mature), year, and month were measured on body weight, incidence of estrus, and incidence and rate of ovulation. There was a significant difference (P<.05) among breed, year, and the interactions for body weight at puberty. The mean age at puberty for 1982-83 was 693.6 days (23.1 months) for Corriedale and 483.3 days (16.1 months) for Criollo. The mean liveweight at puberty was 27.2 kg for Corriedale, and 25.3 kg for Criollo. Corriedale ewe lambs weighed more than Criollo, attained puberty seven months later than Criollo. At comparable age (15-17 months) at the Southern Peruvian Highlands 100 % of the Criollo reached puberty, compared to 58% of the Corriedale. Body weight, incidence of estrus and ovulation were affected (P<.01) by breed, age, year, month, and their interactions. Physical maturity was attained at 39 and 36 months of age for Corriedale, and Criollo, respectively. Weight changes during the year were associated with feed availability. The mean overall incidence of estrus was 45.4 % for Corriedale (43.6 in physically immature, and 47.2 % in mature ewes), and 67.1 % for Criollo ewes (66.3, in physically immature, and 68.7 % in mature ewes). The mean overall incidence of ovulation was 39.6 % for Corriedale (39.7, in physically immature, and 39.5 % in mature ewes), and 58.5 % for Criollo ewes (59.4, in physically immature and 56.7 % in mature ewes). Both breeds demonstrated seasonality of estrus and ovulation with the Corriedale being shorter than the Criollo. The incidence of ovulation in both breeds was less than that of estrus. The ovulation rate was 1.00 for Corriedale, and 1.03 for Criollo (P>.05). Even though Criollo ewes weighed less than Corriedale, they attained puberty earlier, and showed less seasonality in estrus and ovulated …

Aspects Of The Feeding Ecology Of The Bonneville Cisco Of Bear Lake, Utah-Idaho, David C. Lentz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Bonneville cisco (Prospium gemmiferum), a small planktivorous whitefish, is an important part of the distinctive fish community of Bear Lake, Utah-Idaho. The Bonneville cisco plays a key role in the trophic structure by converting zooplankton to fish biomass and providing a major forage source for cutthroat and lake trout. Aspects of cisco feeding ecology studied include characterization of the zooplankton community composition and dynamics and cisco feeding habits and prey selection.

Composition and seasonal dynamics of the zooplankton community were determined for a fifteen month period during 1981-1982. The community was dominated by a calanoid copepod, Epischura …