Thesis (M. Sc.)--Acadia University, 1997. / Includes bibliographical references. Also available on the Internet via the World Wide Web.

Recent studies have advanced our knowledge of factors that could affect problem solving performance, and also of the positive effects of problem solving ability on fitness measures (the ‘what’ of problem solving). However, a missing linkage exists between this ‘what’ and the corresponding ‘how’. Such linkage requires the understanding of how these factors contribute to problem solving. Therefore, the central aim of this thesis is to examine this ‘how’. The roles of learning and behavioural flexibility in the context of problem solving are shown across the experiments, primarily with laboratory and free-ranging grey squirrels and to a lesser extent with wild red squirrels. Under a recurring change, laboratory grey squirrels showed a rapid decrease in the number of errors they made per reversal phase in a serial spatial reversal learning task. Such efficiency is achieved by a gradual tactic change, from sequential to integrative tactics, with increased experience. It also involves support from cognitive mechanisms such as attention and inhibitory control. In a puzzle box task, wild grey squirrels showed that they were better problem solvers than the wild red squirrels. However, red squirrels that solved the puzzle box were more efficient than the grey solvers. Detailed analysis of the results showed that learning and flexibility play independent roles in problem solving. Each process is associated with particular traits that to increase efficiency. For grey squirrels, behavioural selectivity (effective behaviours) and persistence increased with increased experience. Flexibility, however, showed minimal positive effect for them, given that it decreased behavioural selectivity. In contrast, flexibility primarily provided a positive effect for red squirrels’ solving efficiency. These results showed that the two species appear to use both similar and different cognitive processes in solving the task. The discussion gathers the results and explores how learning and flexibility, along with other behavioural traits, vary in their contributions to problem solving performance. As learning and flexibility are definitely not limited in problem solving, the discussion also addresses how these two processes might be involved a construct of general intelligence (‘g’) in animals, and how they are relevant to wilder ecological aspects.

京都大学 / 0048 / 新制・論文博士 / 博士(理学) / 乙第13320号 / 論理博第1567号 / 新制||理||1663(附属図書館) / (主査)教授 本川 雅治, 准教授 中野 隆文, 教授 曽田 貞滋 / 学位規則第4条第2項該当 / Doctor of Science / Kyoto University / DFAM

Hematological comparisons were made on the Uinta ground squirrel (Citellus armatus) trapped at different altitudes and during vari ou s stages of seasonal activity in 1965 and 1966. Hematological variation due to sex, sexual activity and body weight were also analyzed. Ground squirrels were secured from the Mt. Timpanogos area near Provo, Utah County, Utah. Erythrocyte count, hematocrit, total blood hemoglobin, mean erythrocyte volume, mean erythrocyte hemoglobin and reticulocyte counts were measured using standard procedures; banding patterns of hemoglobin and serum proteins wer e determined by means of electrophoresis with polyacetate strips.

The purpose of this investigation was to study the weight changes of selected internal organs to determine possible physiological variation occurring at six different altitudes ranging from 5,800 to 8,500 feetand during the summer season. This report was limited to the study of changes in the adrenal glands, kidneys, testes, heart and intestines. Electrocardiogram, heart and respiration rates were investigated also. These changes were statistically analyzed to determine possible seasonal differences along with any significant changes occurring at different elevations. The results of the study should in part overcome the lack of current experimental data for Citellus armatus.

Golden-mantled ground squirrels (Citellus lateralis Say) typically inhabit coniferous forest regions, but they occasionally occur in desert shrub habitats. The principal purpose of this study was to observe activities of mantled squirrels in a sagebrush community, and to ascertain factors which contribute to their success in an unusually arid habitat. Squirrels of this community belong to the subspecies C. l. lateralis; however, intergradation between typical C. l. lateralis and C. l. castanurus is evident. This community is in the Wasatch Mountains at an elevation of 5,750 feet, and in the Upper Sonoran Zone. These three conditions were not previously recorded for members of this subspecies.

No description available.

Master of Science

The principle objectives of the study were; (1) determine accurately the time of breeding, (2) lactation, (3) breeding age, (4) number per litter, and to obtain other miscellaneous data on this popular game animal. Three study areas of varying habitat were chosen. The President’s Hill (17.5 acres) is located on the V. P. I. college campus; Turkey Pen Woods (3.7 acres) is about one-half mile from the President’s Hill and adjacent to a paved highway, and North Crumpacker Woods (6.7 acres) is about 200 yards from Turkey Pen Woods. A special trap was designed, and 74 were constructed for use throughout the study. The Monel, size I, fish tag was used for tagging the ear of the squirrel. The original handling techniques were patterned from those used by previous investigators, however, shortly after the project was begun a squirrel funnel, made of tightly woven sack and one-fourth inch hardware cloth, was constructed and successfully used throughout the remainder of the study. / M.S.

Introduced species present one of the greatest threats to biodiversity of native species, and knowledge of introduced species ecology is imperative for the development of management plans to ensure conservation of native species populations. We sought to determine the distribution and nesting behavior of an introduced population of red-bellied squirrels (Sciurus aureogaster) on islands of the Florida Keys currently managed as part of Biscayne National Park, and document potential for the species to impact native flora and fauna. Squirrels were difficult to observe in the dense vegetation of the subtropical forest, so we relied on their leaf nests, which were highly visible in the canopy of trees, to determine current presence and distribution on the Park's islands. We found nests throughout the mixed-hardwood forests of Elliott Key and Sands Key, and also documented a single, old nest on Old Rhodes Key, the first ever documentation of the species that far south in the Upper Keys. Nests were located in tall trees with more canopy linkages than random focal trees, and nests were placed in the upper canopy on the north side of the nest tree more often than expected by chance. Squirrels selected West Indies mahogany (Swietenia mahagoni) to place nests more often than available in the forest. Squirrels used areas with greater tree density and canopy cover, but lower recent hurricane damage and fewer woody shrub stems, than areas available at random in the forest. Squirrels built nests only in mixed-hardwood forest. Overall, this introduced species exhibited nest site selection behavior similar to other tree squirrels, and appears capable of continued spread despite the initial site of introduction on an oceanic island. Knowledge obtained from this research is being used by managers and applied to an eradication program to remove this invasive species from Biscayne National Park.