No description available.

Limited work has been done in the field of ecology to relate growth and development of wild ungulates to the quality of their natural forage. This study was conducted in Southeast Alaska during the summers of 1959, 1960 and 1961 to identify the factors of the environment which alter the plane of nutrition of deer (Odocoileus hemionus sitkensis) and result in variations in body size. Woronkofski and Coronation Islands, suspected to produce deer of wide contrast in body size, were chosen as study areas and qualitative and quantitative measurements were made of both the deer and the range on the two islands. A total of 63 deer specimens were collected, from which sex, age, weights and measurements were recorded and samples of rumen contents were collected and analysed. Specimens were examined to determine levels of parasitism. Sex and age status of deer that died from natural causes were utilized for additional data. The range was evaluated through the use of line intercept transects correlated with chemical analyses of major forage species. Results of quantitative analyses of vegetation on the two islands indicate that Woronkofski Island greatly outranks Coronation Island in: 1) plant density and species abundance in the forest (110 to 54 interceptions) and muskeg (297 to 242 interceptions) types, 2) total area of subalpine (4.72 to 1.82 sq.mi.) and alpine (5.00 to 0.24 sq.mi) types and total area of forest type on an equal density basis (13.05 to 11.64 sq.mi.), and 3) total vegetated area on an equal density basis (24.31 to 16.51 sq.mi.). Qualitative evaluation of forage species through the use of chemical analyses did not show significant differences between islands in comparisons of similar species under comparable site conditions. There were indications that alpine and muskeg vegetation was of higher quality than forest vegetation and alpine plants appeared of slightly higher quality than similar species growing on low elevation muskegs. The physiological stage of plant growth appeared to be the most important factor in determining nutritive quality of vegetation. Analyses of rumen samples enabled a clear separation between Woronkofski and Coronation Islands on the basis of range quality. Nitrogen content of both the gross and washed rumen samples was consistently higher in the Woronkofski group than in those from Coronation Island. An inverse relationship existed with respect to the fiber content. Other techniques of rumen contents analyses involving centrifuge fractionation of microorganisms, light transmittancy determinations of rumen liquor and microscope counts of protozoa supported the comparative evidence from the chemical analyses. Regression analyses of weights and skeletal measurements of the specimen deer showed growth differences between the two islands which are apparently attributable to differing levels in the annual nutritional regimens of the deer. Skeletal ratios were found to be more reliable than body weight as measures of growth differences because skeletal parts are less subject to short term fluctuations in the environment and they, therefore, more accurately reflect physiological age. The use of the femur/hind foot ratio supports the thesis that the larger size of deer on Woronkofski than on Coronation Island is the product of nutritional rather than genetic causes. No significant differences, that could be related to nutritional factors, were found in the levels of parasitism among the deer of the two islands. The sex and age composition of the deer populations on the two islands reflects the quality and quantity of forage present on the ranges. Conclusions of the study are that the larger size and more rapid rate of growth of deer on Woronkofski Island in comparison to those on Coronation Island are the result of the psysiological response of the deer on both islands to pronounced differences in the nutritive quality and quantity of their respective ranges. These nutritive factors are primarily operative during the summer period of growth of both the vegetation and the deer. The factors of the environment responsible for the differences in quality and quantity of forage present on the two islands are primarily differences in the degree of altitudinal and topographic Variation and in the relative proportions of alpine and subalpine areas and secondarily in the regional climatic differences and the presence or absence of predation. / Science, Faculty of / Zoology, Department of / Graduate

A study was designed to examine the interaction of axial growth gradients and time specific energy restrictions upon, the growth rates of skeletal dimensions in the Black-tailed deer. A total of 53 new-born fawns was captured and then reared in captivity on controlled energy regimes. The test period of 322 days was divided into five intervals with the energy level in each interval being set as high, medium, or low plane. Representative animals were killed at the end of each interval to examine growth over the previous intervals and to establish a base for evaluating growth in the next interval. Five wild fawns were collected at 112 days and four at 175 days for comparison with the laboratory standards. Relative growth priorities of 23 skeletal dimensions were investigated by challenging skeletal growth with a series of energy restrictions. The amount of growth exhibited by each skeletal element in response to the level of available energy could be integrated into an interpretation of relative growth priorities. Skeletal growth was examined for its ability to provide an indication of total amount and pattern of energy intake over two intervals at the end of 112 days, over three intervals at the end of 175 days, and over five intervals at the end of 322 days. The degree to which the effects of earlier restrictions were removed by compensatory growth was also examined in the fifth interval. A shortage of animals precluded the sacrifice of any standards at 259 days. When skeletal size was graphed against total energy intake, expressed in Calories of apparent digestible energy, at a fixed age, the pattern of energy intake created a distribution of points which could by conveniently bounded by a triangle. On different patterns of energy intake but equal total energy intakes, the relative sizes of the 23 skeletal dimensions change their positions within the boundaries surrounding the distribution of points. A comparison of a set of measurements from an animal of unknown nutritional history with the reference lines in each of the standard triangular distributions leads to a series of energy intercepts that should uniquely characterize the amount of energy consumed by that animal, and the pattern in which it was available. At 112 days, the total energy intake and pattern of restrictions could be derived from skeletal growth. At 175 days, although estimates of total energy intake still appeared to be good, the pattern of energy intake could not be established exactly, but could be limited to a small number of patterns. By 322 days, compensatory growth had reduced differences in skeletal size to the point where neither amount nor pattern of energy availability could be deduced. Four measurements of the fore cannons from wild fawns at 150 days were used to try to define the nutritional regime with a portion of the skeleton which would be readily available from hunter-killed animals. This did not allow a precise evaluation of the nutritional regime for individual animals, but it did point out that there can be tremendous variability in the energy intake of wild fawns from a relatively small area of habitat. It is suggested that a collection of fore cannons should be made along with that of body weights to allow an improved evaluation of range conditions. / Science, Faculty of / Zoology, Department of / Graduate

No description available.

No description available.

No description available.

This study is one phase of a ten-year project designed to evaluate forest-wildlife relationships. The project was initiated in 1958 on the Jefferson National Forest, Broad Run Wildlife Management Area, Craig County, Virginia. The objective of the study was to determine if correlations existed between quantities of available deer browse in the understory of a particular forest cover type and several site quality measurements. The purpose of the study was to determine if weights of browse per acre could be estimated reliably by utilizing easily obtained site quality measurements instead of clipping and weighing browse. Eight site quality measurements (variables) were tested. These were: site index, depth of the A₁ soil horizon, position on slope, basal area per acre, aspect (exposure), percent of slope, elevation, and the number of clipped stems per sampling unit. Fieldwork was conducted in two major forest cover types; the oak, hickory, poplar, white pine type (cove hardwoods type), and the mixed oak-pine type. Sampling units were located randomly, in pairs, within each of these two forest cover types. Each sampling unit consisted of a circular 1/4 acre plot and a square 1/100 acre plot located at the center of the circular plot. A system of double sampling was used to obtain browse weight data and site quality data for comparisons. Data on eight variables recorded at each 1/4 acre sampling unit were compared with the quantity of browse clipped from the 1/100 acre sampling unit located at the center of that particular 1/4 acre plot. A multiple regression analysis was used to determine the degree of correlation between quantities of browse (available browse) clipped from sampling units and all measurements of the eight independent variables (site quality measurements) recorded on sampling units. The final analysis of the oak, hickory, poplar, white pine cover type data indicated that the variables significantly related to browsing weights per acre were the number of stems clipped per sampling unit and the depth of the A₁ soil horizon. These two significant variables explained 48,63 percent of the total variation in browse weights occurring between sampling units. Using only the two significant site quality measurements (independent variables), the final estimating equation was: Y (pounds of browse per acre) = -0.14 + 0.06 (number of stems clipped per sampling unit) + 0.61 (depth of the A₁ horizon, inches). The final estimating equation should not be used for reliable estimates of browse production in the oak, hickory, poplar, white pine forest cover type. A total of 51.37 percent of the variation in browse weights occurring between sampling units is unaccounted for in this equation. The final analysis of the mixed oak-pine cover type data indicated that the only variable significantly related to browsing weights per acre was the number of stems clipped per sampling unit. However, this significant variable explained only 17.97 percent of the total variation in browse weights occurring between sampling units. Using only the one significant site quality measurement (independent variable), the final estimating equation was: Y (pounds of browse per acre) = 2.24 + 0.07 (number of stems clipped per sampling unit). The final estimating equation should not be used for reliable estimates of available browse production in the mixed oak-pine forest cover type. A total of 82.03 percent of the variation in browse weights occurring between sampling units was unexplained in this equation. More research is necessary to determine other easily measured environmental factors (variables) which might bear a significant relationship to quantities of available deer browse produced in the two forest cover types sampled. When several more of these significant variables are discovered, the addition of these variables to the estimating equations for the two cover types might account for a large enough percent of the explained variation to enable the game biologist to use the equations for reliable estimates of browse production. / Master of Science

The purposes of this investigation which was conducted from September 1954 through October 1955, were (1) to determine the differences in available nutrients in selected deer browse species growing on different soils, (2) to investigate the variations in available soil nutrients as they may relate to chemical composition of selected deer browse species, and (3) to determine the variations in available nutrients in the selected browse species during different seasons of the year. The current year’s growth of twigs from flowering dogwood (Cornus florida), black locust (Robina pseudoacacia), and red maple (Acer rubrum) were collected at two-month intervals on study areas whose soils had arisen from either Brallier, Clinton, Huntersville chert, or Martinsburg shale geological formations. A proximate analysis was run on each browse collection. In addition to the above three species, rhododendron (Rhododendron maximum) and buffalo nut (Pyrularia pubera) were collected from the Brallier study area and analyzed. One-third of the samples of dogwood, locust, and maple that were collected after leaf fall in October 1955, were analyzed for calcium, phosphorus, cobalt, and manganese. Soil samples were collected on each area and analyzed by a flame spectrophotometer, LeMotte Soil Testing Outfit, and a rapid method. The soil which arose from the Brallier study area was lowest in value for phosphorous and second highest in values for total exchangeable cations and organic matter. The Clinton study area values were second highest in pH, phosphorous, and base saturation, and was highest in organic matter and manganese content. The chert values were the next lowest for phosphorus and lowest for pH, calcium, total exchangeable cations, and base saturation. The shale study area soil gave the highest values for pH, calcium, phosphorous, base saturation, and total exchangeable cations although it was lowest in organic matter. Of the three browse species collected from all the study areas, dogwood was generally high in moisture content, ether extract, ash, and nitrogen-free extract while being average in protein and low in crude fiber. Locust was high in protein and crude fiber and low in moisture, ether extract, and nitrogen-free extract. Maple was generally high in ether extract, crude fiber, and nitrogen-free extract and low in protein and ash. Rhododendron and buffalo nut were collected from the Brallier study area only. In comparison with the other three species on that area, rhododendron was very high in moisture and nitrogen-free extract; average to low in protein, ether extract, and crude fiber; average to high in ash. Buffalo nut was very high in moisture, protein, and ash; average in ether extract and crude fiber; and low in nitrogen-free extract. Seasonal trends in nutrient values for three browse species collected in all areas were observed. Protein content rose generally during the dormant months. Moisture content decreased from June through December and was followed by a rise that lasted until June. There was a rise in ether extract from September through June whereas the level of ash content was erratic during this period. Crude fiber was fairly stable in red maple and black locust although erratic in dogwood. There was a decrease in the nitrogen-free extract during the winter. Trends and consistencies in the nutritive values of the three species collected on all study areas, based on the study area on which they occur, are generally in the order of being high or low for one or two individual species rather than for all the species, or else they are considerably erratic. The different species have different nutritive values when growing on the same soil. During April and August, the different soils have their greatest effect on the nutritive values of plants; moisture content is greatly affected by the soil, and protein content is only slightly less affected. Except for the months of February and August, at least three of the six nutritive qualities of the plants were affected by the interaction between the plant and the soil. Analyses for minor elements reveal that black locust had the highest phosphorous and cobalt content; dogwood had the highest calcium content; red maple had the highest manganese content. On three of the four study areas, the manganese content of red maple exceeded the toxic level for bovines. On the chert area, dogwood and red maple were deficient, by bovine standards, in cobalt. / Ph. D.

Nutritional quality and availability is thought to regulate geographic patterns of variability in animal body size due to phenotypic plasticity. The purpose of this study is to determine how vegetation quality, abundance and population density influence white-tailed deer (Odocoileus virginianus) body size on a subregional spatial scale at Fort Hood, Texas. Harvest and census records are used to test the hypothesis that white-tailed deer exhibit phenotypic plasticity (e.g. larger body size) in response to differences in vegetation quality and availability. Results from these analyses suggest that forage quality and abundance alone is not a main driver of white-tailed deer body size. Analysis of deer population density (generally) resulted in an inverse relationship with body size. Areas with high quality forage and low population density support larger deer while areas with low quality forage and high density support smaller than average deer. The few exceptions occur in areas exhibiting poor quality forage and low population density or high forage quality and high density. Results from this study suggest that continued overcrowding of deer within isolated areas may eventually lead to efficiency phenotypic conditions producing smaller sized deer. These results could prove useful in interpreting deer population responses to harvest management. For successful local management of deer, studies examining the combined influence of habitat variables (such as forage quality, abundance and population density) on deer health offer managers valuable information needed to establish annual harvest goals and understand deer-habitat relationships relative to carrying capacity.