Thesis (M.S.)--University of Nevada, Reno, 2007. / "August, 2007." Includes bibliographical references (leaves 71-81). Online version available on the World Wide Web.

The genus Ochotona is revised using numerical techniques on 42 craniometric measurements. As a result of this revision 18 extant species are recognized: 0. alpina, 0. collaris, 0. curzoniae, 0. daurica, 0. erythrotis, 0. kamensis, 0. koslowi , 0. ladacensis, 0. lama, 0. macrotis, 0. pallasi, 0. princeps, 0. pusilla, 0. roylei, 0. rufescens, 0. rutila, 0. thibetana and 0. thomasi. A description is given for each species as well as its original reference, synonymies, univariate statistics for the 42 craniometric measurements and a general description of the animal and its habitat. A skull representative of each species and maps outlining general ranges are also presented. Results of linear discriminant function analyses indicate an affinity of species from similar habitats. Phylogenetic relationships among species are discussed, and a cladogram is presented. Changes in overall size dominate the cladogram, with small size appearing to be the plesiomorphic state. Some fossil ochotonid groups are also examined, although the measurement sets used were greatly reduced due to the fragmentary nature of the fossil material. The reduced measurement sets do not appear to be diagnostic of taxonomic differences, but they do appear to be reflective of habitat differences. As a result, the ochotonids may prove to be useful indicators of paleoenvironments. Range reduction due to the influence of climate and competition is also discussed, as is the trend toward an overall increase in body size. / Science, Faculty of / Zoology, Department of / Graduate

Thesis--University of Wisconsin--Madison. / Typescript. Vita. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Texas at Austin, 1999. / Vita. Includes bibliographical references (leaves 184-194). Available also in a digital version from Dissertation Abstracts.

In North America, pikas (mammal genus Ochotona) are distributed throughout the western mountain ranges where they are mostly restricted to higher elevation talus slides. There are two species in North America, the Alaskan or Collared Pika (Ochotona collaris Nelson) and the American Pika (Ochotona princeps Richardson). The former is found north of 58 degrees north latitude and has no subspeciation, while the latter occurs south of 58 degrees latitude and consists of 35 subspecies isolated on various mountain ranges (Hall and Kelson 1959). In Utah there are nine subspecies, which are mostly distributed in the Wasatch range that runs northeast to southwest through Utah. They are also found in the LaSal Mountains and the Uinta Mountains, where this study was conducted. This subspecies of pika, Ochotona princeps uinta (Hollister) is found in the entire Uinta range and extends west into the central Wasatch Mountains.

Pikas from four colonies in the Cascade Mountains of Oregon were examined. Two colonies were chosen from within the geographical distribution of two nominal subspecies. A discriminate analysis of morphological measurements taken from the specimens showed that each colony could be distinguished from each other. Each colony studied showed more intra-colony similarity than inter-colony similarity regardless of distance separating the colonies or subspecies designations. The results indicate that the validity of subspecies designations for this species can be questioned.

Observations or a small group of pikas, (Ochotona princeps) occupying a southwest facing roadfill on Mt. Hood, Oregon (1518 m) were made during the fall or 1976. Territorial sizes of 305.5 m2 and 121 m2 were determined based on territorial displays. These territories were compared with those observed in other studies. The mean distance to the nearest neighbor was 15.1 m. A pair relationship between two of the pikas and a dominance order are discussed. The seasonal progression of the haypiles and the reactions of the pikas to other animals are also noted.

It is the purpose of this study to make gross and histological comparisons of the various segments of the intestinal tracts of the jack rabbit and the pika. The two animals used for this study were the desert jack rabbit (Lepus Californicus deserticola Mearns), and the pika (Ochotona princepts uinta Hollister). The jack rabbits were found only in the desert valleys and low foothills in the areas studied. These areas are typically open bush or sage brush types of communities. The pikas were restricted to certain high rockslides in this region. These areas are described more completely in the section on Methods and Materials. This study is limited to a comparison of the gross and microscopic anatomy of the idgestive tube in these two animals.

Det skrivs en hel del i tidningarna om barn som är utsatta för mobbning. Ca 50 000 elever har någon gång känt sig mobbade i skolan, men bara 500 anmälningar har kommit in till BEO ( barn och elevombudet). I denna studie vill vi synliggöra några lärares syn på mobbning, samt se hur de arbetar förebyggande för att motverka mobbning. Vi vill även ta del av elevers uppfattning om mobbning, delar de samma uppfattning som de vuxna? På de skolor där vi har gjort denna studie arbetar man framför allt med två olika modeller för att motverka mobbning. Dessa två modeller, som är Friends och Farstamodellen, har vi en grundlig beskrivning av. I vår studie använde vi oss av en enkät tagen från Björndell (1997). Vi modifierade den för att passa vårt syfte bättre med hjälp av några lärarintervjuer, som sedan skulle ligga till grund för vår elevenkät. Vi gjorde en kvalitativ elevenkät. Lärarna definierade mobbning som att utsätta någon för trakasserier eller nedsättande ord, där man bedömer det fysiska utseendet eller vad man har för klädsel på sig. Lärarna säger även att man måste lyssna på barnen när de kommer och säger att de blir mobbade, men att man även måste skilja på om det är enskilda händelser eller återkommande. Elevernas svar delade vi in i olika kategorier så som fysisk, social, verbal mobbning. Det mest positiva vi kan se i resultatet är att en stor majoritet av barnen har stor tilltro till sin lärare och dess kompetens att kunna stoppa mobbning. Elevernas tilltro till att lärarna på respektive skolor skulle kunna hjälpa till att stoppa mobbning om det skulle förekomma, är alltså väldigt stark.