Thesis (M. Sc.)--University of Canterbury, 2008. / Typescript (photocopy). Includes bibliographical references. Also available via the World Wide Web.

Thesis (Ph.D.)--Boston University / The electron microscope was used to study comparatively the interrenal tissue of species selected from three vertebrate classes which were chosen as representatives of a particular segment of the evolutionary tree. Certain similarities exist in the interrenals of the species chosen, inasmuch as a similar cordal arrangement of cortical cells, as well as an intermingling of chromaffin and interrenal tissue have been described. In addition, the interrenal cells have been shown to be under the influence of the pituitary gland in all vertebrates. The bases for comparison of the species selected are evolutionary ties, the fact that the interrenal cells produce certain hormones common to all classes, and the fact that the enzymes necessary for hormone production reside in or on the mitochondria. Nine species of animals were used: three amphibians, four reptiles, and two birds, each representing a different order. Several fixatives were tried, but the one most frequently used was a phosphate buffered 1% osmium solution (Millonig, 1962) with modifications to suit the pH and osmolarity of the animal involved. Tissues were fixed for 1/2 to 1 1/2 hours at 4°C. Dehydration was effected in graded acetenes and the material was embedded in either Vestopal W, Araldite 502 or Maraglas 655. Vestopal W gave the most contrast and stability, but was the most difficult to section. Sectioning was accomplished with a Leitz, Hnxley, or PorterBlum microtome with a glass knife. Sections of gold or silver color were chosen for electron microscopy, which were 900 - 1500 A thick (Peachey, 1958). Sections were also cut 1u thick and stained with 1% aqueous methylene blue for light microscopy. The thin sections were picked up on slotted, uncoated grids and routinely stained with phosphotungstic acid. Some were also stained with lead hydroxide or uranyl acetate. The grids were then viewed and photographed with an RCA-EMU-2B or with a Siemens Elmiskop I electron microscope [TRUNCATED]

The alms of this study were to quantify various aspects of predator-prey interactions between Great Black Backed Gulls (Larus marinus) and Common Puffins (Frateroula arotica Le) in order to assess the possible long term effects of predation by gulls on a single Puffin colony and to examine the possible influence of avian predators on Puffin social behaviour. Kiore has been little quantification of the extent of Great Black-Backed Gull predation of Puffins throughout the gull breeding season. Chapter One extends data already published on gull predation of Puffins on the island of Dun, St Kilda, by showing what proportion of gall diet comprised Puffins and by indicating the importance of Puffin prey to gull breading success. Chapter Two describes the ranging behaviour and hunting success of gulls on Dun. Gulls only hunted flying Puffins and concentrated their hunting efforts in areas near, but not directly over, their own nests. Any one pair of gulls shared on average about one third of its hunting range with two or three other pairs of Gulls attempted to catch Puffins most often in areas where Puffins, flying in polarised flocks termed 'wheels', habitually turned in to fly over land or out to fly over the sea. With increasing numbers of Puffins in a wheel, gulls made fewer attempts to catch Puffins and took longer to make a successful kill. The grouping behaviour of Puffins is one of the most striking features of the species' social life at the breeding colony. Chapter Three describes and quantifies temporal and spatial aspects of Puffin grouping behaviour at a. variety of colonies. Differences in the diurnal phasing of the formation of different types of Puffin groups and Abstract (cont.) regularities in the spatial distribution of groups in the sea and in the air indicate that individual Puffins regularly synchronised some of their movements in and around the breeding colony with numbers of other Puffins breeding in or using the same part of the colony. The flight behaviour of an individual Puffin in a wheel flock above a sub-colony was influenced by the number of other Puffins in the wheel, b-wind speed and direction, and by the presence of a hunting gull in the vicinity of the wheel. To conclude, the implications of the present study for the management, monitoring and future study of Great Black-Backed Gulls and Puffins are outlined.

No description available.

The pathological effects of infections of Dlspharynx nasuta (Nematoda: Acuariidae) on confined, experiment ally-infected chicks of the blue grouse, Dendragapus obscurus, have been studied. The severity of the infection was found to be directly proportional to the number of worms present and the youth of the host. The development of the lesion produced at the site of infection, the proventriculus of the host, is described and its papillomatous nature confirmed. The previously unknown developmental stages of D. nasuta in the avian host are described and related both to the formation of the lesion and to the disease process. The growth of infected birds, expressed as gain in weight, was less than that of the controls although food intake studies indicated that the amount of food eaten by both groups was comparable. Calcium and phosphorus analyses on bones gave no indication that the mineral metabolism of infected birds was affected although their bones broke more readily than those of the controls. Development of the Juvenal feathers which appear from 3 to 5 weeks of age may be severely retarded. These observations suggest that the protein metabolism of the host is impaired. The numbers of hemocytes of infected grouse fluctuate greatly and show two critical low periods. The first, occurring immediately after infection, can be correlated with the invasion of the larvae and possibly to a substance secreted by them. The second occurs 2 to 3 weeks after initial infection and can be correlated with local irritation and hemorrhages and perhaps the moult of the larvae. Chronic hematological symptoms are anemia and leucocytosis. The latter is characterized by heterophil ia, eosinophilopenia, lymphocytosis of small forms and lymphopenia of the larger forms. The presence of circulating antibodies for D. nasuta was not demonstrated with the techniques used. The evidence suggests that the host tissue reaction may be an allergic response. Several ecological questions concerning the survival of D. nasuta during the winter months, temperature for larval development in the intermediate host, longevity of adult D. nasuta in the definitive host, infection and reinfection of adult blue grouse, are considered. In the laboratory, infections of 16 and 22 worms, administered to the host before 2 weeks of age, were fatal. Results of these experiments indicate that D. nasuta is a debilitating pathogen which may prove fatal and, may act as a controlling factor of natural grouse populations. / Science, Faculty of / Zoology, Department of / Graduate

The ribonucleotides in the chorioallantoic membrane of 12-day-old chick embryos have been isolated by ion-exchange chromatography and characterized by their spectrophotometric and paper chromatographic properties. The following nucleotides were identified: adenosine-5' phosphate (AMP), uridine-5' phosphate (UMP), cytidine-5' phosphate (CMP), uridine-5' diphosphate galactose (UDPGal), uridine-5' diphosphate N-acetyl hexosamine (UDPNAHexosamine), guanosine-5' phosphate (GMP), cytidine-5' diphosphate (CDP), uridine-5' diphosphate (UDP), adenosine-51 diphosphate (ADP), guanosine-5' diphosphate (GDP), cytidine-5' triphosphate (CTP), uridine-5' triphosphate (DTP), adenosine-5' triphosphate (ATP), and guanosine-5' triphosphate (GTP). Quantitative determinations of these nucleotides were made on the basis of their ultraviolet absorption at 260 mμ. Similarly, concentrations of these nucleotides were estimated in 12-day-old chorioallantoic membranes after infection with vaccinia virus. Larger amounts of ribonucleoside-5' phosphates were present in the infected tissue at 4 and 12 hours after infection. The amounts of ribonucleoside-5' triphosphates were decreased. In tissues where, it is believed, synchronous infection occurred, the amounts of ribonucleoside-5' diphosphates and triphosphates were markedly lower than in controls after 12 hours of infection. Infection in the presence of tritium₌labelled thymidine showed that the amount of labelled thymidine-5' mono-, di-, and triphosphates had increased after 4 hours and that the amounts of these nucleotides subsequently decreased. / Science, Faculty of / Microbiology and Immunology, Department of / Graduate

The reported tendency for island birds to possess larger wings and bills than their mainland counterparts, was investigated by a study of the passerine birds of the Tres Marias Islands, Mexico. It was found that several species showed this bill trend, but that a tendency for birds to possess larger wings was less apparent; an unexpected tendency for the tarsus of island birds to be large was also demonstrated. On The other hand, there is no apparent tendency for the body-size of island birds to be larger than that of their mainland counterparts. The bill and tarsus characteristics of the Tres Marias birds are also shown by many other passerine birds in islands situations elsewhere in Mexico and North America. The differences in dimensions between mainland and Tres Marias birds cannot be explained as adaptations to different climatic conditions (Allen’s rule). Observations of feeding behaviour and analysis of gizzard contents of collected specimens reveal that some island species have a diet which is different from that of their mainland counterparts and that their use of perches is different too. This suggests that the bill and tarsus are used differently in the two regions. It is postulated that large bill and tarsus are adaptations to a greater exploitation of the environment. Differences inhabit at between the mainland and islands do not account for differences in feeding behaviour, but the relative paucity of specie on the islands offers and explanation. It suggests that there is some more environment available for exploitation to each of those present on the islands that to those on the mainland, assuming that there are approximately equal resources in the two regions. There is additional indirect evidence to suggest that the absence of several species has important effects upon those present. Island birds tend to be more drab in plumage that mainland birds on the Tres Marias and elsewhere and at least one species on the Tres Marias has reduced vocal repertoire. In view of the value of distinctive plumage and song as specific recognition characteristics the futures displayed by the Tres Marias birds may be attributed to the absence of systematically closely-related species. At least one species nests considerably lower in the vegetation On the Tres Marias Islands than on the mainland, which may be due to the relative absence of predators on the islands. There is evidence to suggest that the ecological conditions which have permitted the evolution of bill and tarsus characteristics in island birds, have permitted the evolution of large body-size in island rodents also. If this is true, then it is possible that the recorded tendency for animals to become larger in the course of evolution is related to an increase in the amount of environment available for exploitation. / Science, Faculty of / Zoology, Department of / Graduate

The purpose of this study is to investigate experimentally some ecological aspects of social behaviour in Song Sparrows, Melospiza melodia, on Reifel Island, British Columbia. Two main questions are asked: A. Does the temporal pattern of settling on territories influence the number of occupied territories, and hence territory size, and the breeding density in a given area? B. Are the juveniles that obtain territories, when the opportunity arises, the dominant individuals in dominance hierarchies established during the pre-breeding season? A necessary pre-requisite for both questions to be answered is that there exists a surplus of birds which are non-territorial and potentially capable of breeding, but which are prevented from taking territories by the resident territory holders. This also is experimentally investigated. Removal experiments were carried but in the fall of 1972 and the spring of 1973. Subsequent replacements and breeding showed that there was a surplus of Song Sparrows on the study area that were physiologically capable of breeding. All but one of the replacement birds were juveniles, and all were probably of local origin. Two types of removal experiments, simultaneous and successive, were carried out in both the spring and fall. On the Simultaneous Removal areas, total replacement took about nine to ten days. Significantly more territories were taken, and the increases in both spring and fall were about 40%. Further, the mean territory size after the removals was significantly smaller than that before. Finally, territory boundaries were completely rearranged following the removals. The replacement on the Successive Removal areas took upto three to four days. There was no significant difference in the number of territories taken, nor in the mean territory size, after the removals. Further, the territorial pattern was retained. Breeding density on all areas, however, remained much the same before and after the experiments. Therefore, there were several unmated males with territories after the removals, and these unmated males proved to have significantly smaller territories than mated ones. Factors which could have accounted for the different results of the simultaneous and the successive removal experiments are discussed, and a proposed explanation is given. Dominance hierarchies were determined in the loose groups of juvenile Song Sparrows that congregated over the winter at certain localities along the hedgerows. Each group tended to be a discrete unit, although some interchange of individuals (both dominant and subordinate) occurred. The hierarchies themselves were stable and essentially linear, with few reversals and the occasional triangle. The removal experiments presented an opportunity for some of the members of the hierarchies to obtain territories. It was found that dominant males in the hierarchies were the successful ones in establishing territories. Further, in the largest hierarchy, out of 12 juvenile males, 4 from the top 5 obtained territories. Factors which could possibly influence the position of the bird in the hierarchy are discussed, and the possible outcomes of the hierarchy are considered. / Science, Faculty of / Zoology, Department of / Graduate

The ecology of urban birds—populations, foraging ecology, and nest-sites—was studied between 1968 and 1970, mostly in Vancouver, British Columbia. Four census plots in Vancouver, each in a different habitat type, were studied year-round. Additional winter studies were made on two plots each in Sacramento, California and Ottawa, Ontario and on two additional Vancouver plots. Breeding bird densities on the Vancouver plots were lower than those in some other urban areas, but comparable to those in most non-urban habitats. Densities decreased with increasing urbanization. In winter, densities were generally higher than in the breeding season, and were much higher than those in non-urban habitats. Winter densities, unlike breeding densities, increased with greater urbanization. The availability of food is probably a major cause of the high winter densities. Sacramento and Ottawa both had lower winter densities than Vancouver. The species diversity of the urban plots was low at all seasons. This results both from a small number of species and a low equitability (i.e., dominance of the population by a very few species). On the Vancouver plots, species diversity was highest in the breeding season, owing to a higher equitability then. The latter probably results from territorial behaviour, which makes it less likely that one or two species will dominate the community. The urban bird populations were dominated—especially on the most urbanized plots—by House Sparrows, Starlings, and Rock Doves. An attempt is made to explain how the biological features of these three species make them especially well suited to the urban environment. Two types of observations—stopwatch observations and spotchecks —were used, in studies of foraging ecology. This phase of the study was confined to the Vancouver plots. An analysis of the stopwatch observations revealed that nearly every species had a distinctive foraging pattern. The only pair of species which had closely similar patterns were the Starling and the Robin. However, these two had quite different foraging methods and utilized different foods. The spotchecks, being discrete, were amenable to statistical testing. Tests were carried out to see whether the use of different microhabitats corresponded to their availability, and to check for differences between species. In both cases, only tests involving the Crested Mynah failed to show significant differences. This lack of significance is believed to be merely the result of a small sample size. Nest-sites were also studied. Interspecific differences in nest height and placement were demonstrated. A conspicuous feature was the almost total absence of nests near the ground. Cat predation and human disturbance are probably responsible for this. In closing, some general features of urban bird ecology are discussed. The importance of studying the foraging ecology of unrelated species, as well as of related ones, is stressed. While two related species with similar foraging ecology usually occupy different habitats, the same, is probably true of unrelated species to a lesser degree. The foraging patterns of urban birds may be expected to overlap more than those of non-urban birds, and nest-site availability may be particularly crucial to birds in cities. / Science, Faculty of / Zoology, Department of / Graduate

Environmental factors (extracellular macromolecules) possibly operating in somite differentiation were examined by using an in vitro system with myogenesis as the end point. It was found that differentiation depended on the time of removal of the somitic tissue from the host, i.e. between stages 17 and 26 (2½ to 5 days of age), and the question was raised as to the relation of these observations and the appearance of glycosamino-glycans (mucopolysaccharides). A review of the literature revealed that no information was available on this subject so that an examination of the time of appearance, distribution, and nature of the glycosaminoglycans and neutral polysaccharides in the axial region (dermatome, myotome, scleratome, neural tube and notochord) of the developing chick embryo during early somite differentiation was necessary. It became apparent that both histochemical and biochemical analysis were required to identify, quantify, and localize the glycosaminoglycans since histochemical techniques alone limit the interpretations possible because interference from proteins and glycoproteins could not be ruled out. Histochemical analysis indicated that there was very little sulphated anionic glycosaminoglycan present in the early embryonic stages examined. The cytoplasm of cells in all axial areas contained strongly acidic material, but extracellularly, sulphated anionic glycosaminoglycans were almost all confined to the notochordal sheath. The extracellular matrix in all areas contained weakly acidic anionic glycosaminoglycans. With development, the weakly acidic anionic glycosaminoglycans increased in concentration in most areas, but most noticeably in the neural tube and scleratome. The concentration of sulphated anionic glycosaminoglycans also increased and they began to appear in the extracellular matrix in all areas although never attaining the deep staining intensity demonstrated by the weakly acidic anionic glycosamino-glycans. By stage 25, however, the extracellular matrix of the scleratome around the notochord was mostly sulphated anionic glycosaminoglycans. Testicular hyaluronidase digestion suggested that most of the stainable material was either hyaluronic acid or chondroitin 4- and/or 6-sulphate (chon-croitin sulphates A and/or C). A small amount of strongly acidic anionic glycosaminoglycan present in the scleratome, neural tube and notochord was polysulphated. Biochemical analysis confirmed that the weakly acidic anionic glycosaminoglycan was hyaluronic acid and that the sulphated anionic glycosaminoglycan was mainly chondroitin 4- and/or 6-sulphate (chondroitin sulphate A and/or C). Only trace amounts of dermatan sulphate (chondroitin sulphate B) were present. A small amount of heparin could be present since some glucosamine was present in the sulphated fractions. This heparin could account for the polysulphated material observed with histochemical staining. On a quantitative basis, the hyaluronic acid concentration (uronic acid/gm dry wt. of tissue) was at a peak between stages 21 to 25 and was greater than the chondroitin sulphate concentration up until stage 25. After that stage, the chondroitin sulphate concentration began to increase very rapidly, concomitant with the formation of cartilage around the notochord, and the hyaluronic acid concentration began to decline slowly. Thus, whereas the hyaluronic acid content was 2½ times greater than the chondroitin.sulphate content in stage 17 embryos, this ratio was almost completely reversed by stage 28 due to the rapid increase in chondroitin sulphate. Histochemical staining supported these findings. It would seem that the increase in sulphated anionic glycosaminoglycans is directly related to cartilage formation while the high hyaluronic acid content present during stages 21 to 25, a time in development when myotube formation and scleratome cell aggregation and orientation are occurring, may play some more general developmental role in somite differentiation. / Science, Faculty of / Zoology, Department of / Graduate