Metacommunity theory has been particularly useful in understanding the way spatially structured communities assemble. Both niche and neutral processes are known to influence metacommunity assembly, and the relative influence of each depends on the level of dispersal-limitation. Contemporary trait-based analyses of metacommunity assembly have enhanced our understanding of these processes. Of the traits investigated, individual personalities have received the least attention, but have been suggested to be drivers of metacommunity assembly model parameters, such as dispersal tendencies and patch density. I address this topic from three angles, three chapters, in this dissertation. First, I used a three-year field survey of fish metacommunity assembly in Everglades National Park to investigate the influence of dispersal-limitation on trait-based metacommunity assembly, asking which traits were important under different levels of dispersal-limitation. I found that the relative influence of traits and local environmental factors decreased, and the influence of regional factors increased with increasing dispersal-limitation. The Rocky Glades has recently been invaded by a micropiscivore with many novel traits, the African Jewelfish. In the second chapter I used my field data to ask what influence this invader has on metacommunity assembly. Overall, African Jewelfish abundance was the third most influential factor in driving assembly. I also used data, which were previously collected by collaborators, from three years prior and two years following the invasion to observe shifts in assembly rules. Assembly became significantly more aggregative immediately following the invasion, a condition which persisted more than a decade later. All previous studies asking the same question, found the same result: invasive introductions correspond with increased species aggregation. This may be a consistent, taxa-independent signal of truly invasive species that can be detected early in the invasion process, making it a potentially useful management tool after further empirical review. In the final chapter, I investigate the potential influence of individual personalities on a metapopulation’s structure. To do this, I used a behavioral individual-based model to explore the influence of sociability, an individual’s propensity to associate with conspecifics, on metapopulation structure at ecologically relevant spatiotemporal scales. I found that individual sociability can significant influence key metapopulation parameters such as dispersal distance and patch density but may not influence landscape occupation. Chapter three concludes with new hypothesis to be evaluated by future field studies. Overall, this dissertation demonstrates the relative roles of invasions, species traits, and individual personalities on metacommunity assembly processes.

Retention of young cattle and marketing older cattle from the range has been suggested as one of the profitable means of adjustment for the cow-calf operator. This study was to determine the impacts of the shift from cow-calf ranching operation to cow-calf-yearling operation on the feed energy budget of the ranch, cow herd size, beef production and market price of beef. Ten alternative livestock management options involving cow-calf-yearling operations were tested for these impacts, using two representative Utah size ranches (150 and 300 cow ranches). The extra feed needed to accomodate the increased number of yearlings and the decrease required in brood cow herd size were estimated. Changes in beef production in Utah, the Western eleven States, and the change on national price of beef were estimated from marketing projections of four types of beef. These projections were based on three levels of adoption for the management options by producers in each area. Under complete retention of home grown calves, the total amount of feed required to support the typical cow-calf operation was 93% of the total feed needed for the cow~calf short yearling and 85% of the total feed required for the cow-calf long-yearling operation. Only the production of long-yearlings resulted in a considerable decrease in brood cow carrying capacity (8 to 31%)· Marketing baby-beef and grass-fed beef produced a substantial decrease in beef tonnage and a corresponding increase in beef price. Light-fed short-yearlings and heavy-fed beef (from both short and long yearlings) showed a considerable beef increase in Utah and the western region. Only the marketing of heavy-fed short-yearlings produced a positive change in the beef produced nationally and a slight decrease in beef price (0.3 to 2 %) •

This book was assembled using the latest information for compiling the nutrient requirements of sheep, goats, cattle and water buffalo. Because of the complexity of the interactions between an animal, its diet, its physiological state, and the environment; the values depicting the nutrient requirements are estimates and not absolutes. These values, however, are considered to be adequate to meet the minimum requirements of healthy animals maintained in a thermoneutral environment. The mean energy and protein values used in the nutrient tables were arrived at from combining values found in the literature and those provided in personal communication with animal nutritionists in many developing countries. In some cases, only two or three observations were found for estimating the values used. Future research in ruminant nutrition should be designed to provide information needed to confirm or modify the values presented here. Feed composition tables representing feeds commonly found in Latin America, Africa, Asia and the Middle East have been included for an easy reference when formulating diets. Units of expression of data in the tables of feed composition and animal nutrient requirements are presented using three systems: Metabolizable energy (ME), net energy (NE); total digestible nutrients (TDN) and Scandinavian feed units (FU). conversion factors from SE to ME, TDN, etc., are presented in Section 1 for those who need this information. Also a list of abbreviations used appear in Appendix 5. A brief discussion showing three methods of calculating rations by hand are presented. Each of these methods permits some consideration for calculating a "least-cost" ration. It is important, however, that the person formulating a diet has a knowledge of the animal's nutrient requirements, an understanding of the digestibility and utilization of feeds and the various combinations required to formulate a diet adequate to supply all the needs of animals. Examples of hand calculated rations appear in Appendix 3. Adulteration of feedstuffs is a common complaint from livestock producers in many developing countries. This problem has been encountered at various times throughout most regions of the world. In section 12, some suggestions are offered as a means to establish quality control regulations and to set standards for all manufactured feedstuffs offered for sale.

PART I The horse numbers of Utah had not been accurately counted since the early 1960's. It was estimated that horse and pony numbers were reaching heights as recorded before the age of tractors and automobiles. Horsemen in Utah were asking for financial assistance for public horse facilities from the Utah legislature. The first part of this study was to survey the horse population to determine an accurate count of Utah horses. PART II In order to be satisfied that the horse industry deserved the spending of public funds, it was necessary to know the economic contribution of the horse industry. Part II information came from a second survey of expenses and incomes of horse owners. This study was to determine the economic importance of the horse industry to the State' s economy. The entire study was to determine the horse population and the impact of the horse industry on the economy of Utah.

This paper entails the economic and biological responses of both rangeland grasses and livestock grazing rangeland grasses to nitrogen fertilization. Five sites received graduated rates of fertilizer in previous studies. Analysis showed all sites failed to exhibit a significant carry-over response to fertilization. Determination of optimum rate or optimum reapplication schedule was not possible due to residual nitrogen present in the soil. Spring application of fertilizer produced the greatest returns from one site while the other site studied failed to produce a profitable response from either spring or fall application. Calf weight gains were shown to be curvilinear and resulted in the production function: Y = 13.99 + .2049N - .00087N2 where Y is the total pounds of calf gain per acre and N is the pounds of nitrogen applied per acre. Economic analysis of costs and returns of both cow-calf operations and estimates of costs and returns from yearling stockers operations indicated that neither operation was economically feasible.

To provide accurate data concerning sheep losses resulting from predation, a verification study of sheep predation was initiated in March 1972 in the Cedar City area of Utah. In cooperation with the Cedar City Wool Growers Association and Southern Utah State College Experimental Farm, ten sheep ranches were chosen as sample operations, forming the data base for the initial phase of the study (1972-1974). Cooperating ranchers were asked to promptly report all sheep carcasses or injured sheep, so that an examination could immediately be made to ascertain the cause of death or injury. Daily horseback searches were also conducted on the spring and summer ranges. Every located sheep carcass was examined to determine cause of death. If a predator was responsible, the kill was photographed and location, date, species of predator and age class of carcass was recorded. Coyotes were the principal predator inflicting 89 to 100 percent of the kills. Lambs were the principal age class of predator kills. The number of sheep carcasses found and verified as predator kills and natural losses was substantially less than the total number lost. Therefore, a proportion was used to estimate the total predation rate. The average predation rate was 5.9 percent expressed as a percent of lamb crop. In the final year of the study (1975) three herds were chosen and research efforts were intensified and the validity of the statistical inference was confirmed. An estimated total predation loss of 3028 lambs was incurred by herds 1-10 in 1972 to 1974. In 1975, 158 lambs were destroyed by predators in herds 1, 3 and 5. These losses were valued at $89,347. Assuming the sample predation rate is representative of predation losses throughout Utah, the state-wide lamb loss to predators was calculated to be 127,521 lambs, representing a direct income loss to the Utah sheep industry of $3,622,061. The indirect or multiplier losses represented an additional $10,072,911 loss to the state economy. Two models were developed. The first, a cost model, illustrated the nature of the costs of coyote predation, their effects upon the rancher and several approaches to profit maximization with and without coyote predation. The second model approached predation economics from a biological standpoint to identify research needs for future inquiries into predation economics. The relationships between coyote population dynamics, coyote control and predatory sheep losses were discussed, leading to the formulation of an economic production function model. The model provides a conceptual framework to determine the effectiveness and optimum rate of predator control efforts.

A cell synchronization technique was used that consistently yielded numerous elongated chromosomes, which are necessary for producing high-resolution G-banding. The prometaphase stage of contraction was determined to have the greatest utility for detailed comparative analysis and, therefore, was used in the preparation of the proposed standard high-re solution karyotypes and idiogram. A proposed standard high-resolution G-band karyotype of the domestic sheep and goat is presented, along with a high-resolution G-band idiogram of the goat. The karyotypes presented contain considerably more bands than contemporary karyotypes and provide much greater resolution for linear differentiation. The X chromosome of the sheep is acrocentric, rather than having a minute p arm as recently reported. A side -by-side comparison of high-resolution G-band sheep and goat chromosomes indicates identical equivalence of banding patterns. Of special note is the homology of banding patterns for the six acrocentric autosomes of the goat and the respective three submetacentric autosomes of the sheep, reinforcing the evidence that the goat is representative of the ancestral karyotype. C-bands and NORs of the sheep and goat are also presented. When C-banded, the centromeric regions of the sheep and goat acrocentric autosomes were found to be densely stained. The centromeric regions of the X and Y, however, were not stained differently from the chromosome arms. In the sheep submetacentrics, chromosomes 1 and 3 showed weak C-bands while chromosome 2 showed stronger bands. In the sheep and goat, 10 NORs located terminally on five chromosomes pairs were found. Sheep NORs occurred on the three pairs of submetacentric autosomes and on one large and one small pair of acrocentric autosomes. Goat NORs occurred on four large and one small pair of acrocentric autosomes. Sine the banding patterns obtained when staining for NORs do not permit individual identification of each chromosome, duplicate G-banding and silver staining of elongated chromosomes of both sheep and goat would need to be conducted to identify specific NOR-bearing chromosomes.

Prairie dog control was found to be economically feasible on the Conata basin in South Dakota with future annual maintenance control to prevent re-invasions. The large difference between the present net worth values of the two viewpoints ($2587 for the U.S. Forest Service acting as an agent of the sovereign and $109,011 for the ranchers ) was due to the added costs of environmental considerations included in the U.S. Forest Service control program, but assumed not to be included in control by ranchers. In order for prairie dog control to remain economically feasible, annual maintenance control for the U.S. Forest Service must be below 5 percent of the total initially controlled acreage in the control program (9 percent for the rancher viewpoint). Sun sedge (Carex heloiphila) constituted the major cattle forage increase from control in this study while western wheatgrass (Agropyron smithii), the dominant mid-grass in the area, showed no increase in production after five years of prairie dog elimination. Overall, 84 pounds per acre of usable cattle forage was gained from control.

Stomach contents of 3,672 Dolly Varden char collected from September 1967 to November 1968 were examined to determine the food habits of this species. Of these, 3,100 (86%) had food in their stomachs. Aquatic invertebrates (Insecta and Crustacea) comprised over 90% of the diet. Food habits varied with habitat. Aquatic insects were most important in the diet of stream fish while aquatic insects and crustaceans were most important in the diet of lake fish. Food habits of lake fish were re- 1ated to lake bottom type and access to the sea. Fish in landlocked lakes fed primarily on aquatic insects, fish, and fish eggs. In lakes with access to the sea, crustaceans, followed by aquatic insects, were the major food items in those with firm bottoms adjacent to shore while aquatic insects, followed by crustaceans, were the major food items in those with muck bottoms adjacent to shore. As fish size increased, feeding activity decreased and aquatic insects became less important in the diet while crustaceans and fish became more important. During summer, feeding activity was highest for lake fish while it was highest during autumn and summer for stream fish. Aquatic insects were the dominant food item in summer while crustaceans and fish were dominant in spring and autumn. Mature and immature fish of similar size ate similar organisms. Mature fish, however, fed more sporadically prior to spawning. Feeding activity was highest during daylight hours. Dolly Varden selected larger food items, such as insects and amphipods and ignored small items such as nematodes and oligochaetes.

Turkey production in Utah is one of the most important farm enterprises of the state. In 1945, 11.5 percent of the total farm cash income of the state was from the turkey enterprise. In 1946, 9.4 percent came from this source. Turkey production made up 8.9 percent of the total cash income from farm enterprises in 1944; 5.8 percent in 1945; 4.9 percent in 1940; 1.7 percent in 1935; and 1.3 percent in 1930. The objectives of this study were: (1) to ascertain charges for processing and hauling turkeys from the farm to the processing plants; (2) to determine the average and variation in size and grad of hen and tom turkeys processed by grower and plant; (3) to ascertain where Utah turkeys were marketed in 1947-48 and (4) to determine the average and variation in prices received by Utah growers for turkeys in1947-48.