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Aerodynamic measurements on some special wing features of nocturnal owls and their acoustic significanceGerakis, J.G. (Jeffrey George) January 1985 (has links)
No description available.
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Aspects of the Ainu spiritual belief systems: an examination of the literary and artistic representations of the Owl God.Kameda, Yuko 19 April 2011 (has links)
This study will examine the integral role of owls in Ainu spiritual belief systems
through the means of Ainu oral literature and Ainu material arts. In the past, the
indigenous people known as Ainu lived only in northern Japan, including Kurile Islands
(“Kurile Ainu”), Sakhalin (“Sakhalin Ainu”), and Hokkaido (“Hokkaido Ainu”). Today,
Ainu people live across Japan; however, Hokkaido is considered their spiritual homeland
and the majority of the population lives in this northern prefecture. This paper will focus
on the group of people called “Hokkaido Ainu”. Before a large number of Japanese
migrated to Hokkaido during the Meiji era (1868-1912), Ainu people had lived close to
nature through various activities such as fishing, hunting, and gathering. As a result of
these daily activities involving nature, the Ainu developed their spiritual belief systems.
For example, they believe that various spirits exist in natural phenomena such as plants,
insects, and animals. Among these animals, the bear, killer whale and owl are considered
in many Ainu societies as the highest-ranked animal kamuy, meaning gods or deities. The
Owl God in particular, is believed to be the guardian of the village. In this project, the
symbolic representation of the Owl God in four different Ainu traditional folklores and
various forms of arts will be carefully examined. The goal of this study is to demonstrate
that although the language and physical communities are under threat by Japanese
migration and a modern industrial economy, the spiritual belief in the Owl God as the
guardian of the village continues to exist in contemporary Ainu works of art. In addition,
I will argue that the representation of the Owl God, Kotan-kor-kamuy, is an important
symbolic expression of Ainu cultural identity. / Graduate
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Sociological perceptions of harvesting, husbandry and sustainable utilization of redundant second-hatched chicks of wild hornbills, eagles and owls at Makuleke Community and the surrounding villagesMakatu, Shumani Elsie January 2000 (has links)
Thesis (M. A. (Sociology)) -- University of the North, 2000 / Refer to the document / NRF (National Research Foundation)
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Estudo morfológico da retina e genético do pigmento visual LWS de cinco espécies de corujas e sua relação com o ritmo circadiano / Not informed by the authorVasconcelos, Felipe Tadeu Galante Rocha de 21 November 2017 (has links)
As corujas formam um grupo diversificado, estando presentes em diversos habitats ao redor do globo e têm diferentes padrões de atividade, com espécies diurnas, noturnas e crepusculares. Os fotorreceptores encontrados em corujas são os bastonetes e três classes de cones, levando potencialmente à tricromacia, e as demais camadas da retina mantém a mesma organização de outras aves. O gene LWS tem sido estudado em aves e o pico de absorção espectral da opsina expressa por esse gene está entre 560-570nm. Exceções foram reportadas no melro-preto (P557), pinguim Humboldt (P543) e na corujado- mato (Strix aluco). Entre esses três gêneros, somente as corujas apresentam espécies com diferentes hábitos circadianos. Dessa forma é possível que diferentes adaptações visuais possam ser encontradas em associação com o padrão circadiano. Neste trabalho foi investigada a morfologia da retina e a genética do pigmento visual LWS de cinco espécies de corujas com diferentes ritmos circadianos: Asio clamator, Megascops choliba, Tyto alba (noturnas), Athene cunicularia e Glaucudium brasilianum (diurnas). Um indivíduo de cada espécie foi utilizado nos experimentos. Foi realizada a extração de RNA a partir de uma retina homogeneizada de cada espécie e o RNA mensageiro (mRNA) foi convertido em DNA complementar (cDNA). Partes do gene LWS foram amplificadas utilizado a reação em cadeia da polimerase (PCR) e sequenciadas utilizando a metodologia de Sanger. Cinco sítios importantes para o ajuste espectral da opsina LWS (164,181, 261, 269 e 292) foram analisados e comparados com a sequência de outras aves e da rodopsina bovina, a qual foi referência para determinar as posições dos aminoácidos. No estudo morfológico, foram realizados cortes transversais em criostato de uma retina de cada espécie de coruja. Para a reação de imunohistoquímica foi utilizado o anticorpo Rabbit anti opsin (AB5405) para marcar cones L/M e DAPI marcando núcleos celulares. Também foi realizada a coloração de Hematoxilina-Eosina (HE) para visualizar a organização da retina. A partir das análises morfológicas foi possível observar a presença de cones nas retinas das cinco espécies de corujas, bem como uma organização laminar semelhante a de outros vertebrados. Para todas as espécies estudadas, os resultados da análise de sequência da opsina LWS foram: A164, H181, Y261, T269 e A292. Ao menos para o gene LWS, não foram encontradas diferenças entre espécies diurnas e noturnas de corujas / The owls forms a diverse group present in many habitats around the world and they have different activity patterns, with diurnal, nocturnal and crepuscular species. Photoreceptors found in owls are the rods and three classes of cones that potentially provide trichromacy, and the other retinal layers maintain the same organization of other birds. The LWS gene has been studied in birds and the peak spectral absorption of opsin expressed by this gene is between 560- 570nm. Exceptions were reported on blackbird (P557), Humboldt penguin (P543) and tawny owl (Strix aluco). Among these three genera, only owls have species with different circadian habits. It is therefore possible that different visual adaptations can be found in association with the circadian pattern. In this study the retinal morphology and the genetics of LWS visual pigment of five owl species with different circadinan habits were investigated: Asio clamator, Megascops choliba, Tyto alba (nocturnal), Athene cunicularia e Glaucudium brasilianum (diurnal). One individual of each species was used in the experiments. RNA extraction was performed from a homogenized retina of each species and messenger RNA (mRNA) was converted into complementary DNA (cDNA). Parts of the LWS gene were amplified using the polymerase chain reaction (PCR) and sequenced using the methodology of Sanger. Five important sites for the spectral tuning of the LWS opsin (164, 181, 261, 269 and 292) were analyzed and compared to the sequence of other birds and bovine rhodopsin, which was referenced to determine amino acid positions. In the morphological study, cross - sections were performed in cryostat of a retina of each owl species. For the immunohistochemistry reaction, the rabbit anti-opsin antibody (AB5405) was used to label L / M cones and DAPI labeling cell nuclei. Hematoxylin-Eosin (HE) staining was also performed to visualize the organization of the retina. From the morphological analyzes it was possible to observe the presence of cones in the retinas of the five species of owls, as well as a laminar organization similar to that of other vertebrates. For all species studied, the results of LWS opsin sequence analysis were: A164, H181, Y261, T269 and A292. At least for the LWS gene, no differences were found between diurnal and nocturnal species of owls
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Ecotoxicological simulation modeling: effects of agricultural chemical exposure on wintering burrowing owlsEngelman, Catherine Allegra 10 October 2008 (has links)
The western burrowing owl, Athene cunicularia hypugaea, is a Federal Species
of Concern, whose numbers and range have been drastically reduced from historic levels
in Texas. Burrowing owls roost and forage in agricultural areas, and it has been
hypothesized that exposure to insecticides may be a factor in the decline of their
population. Burrowing owls wintering in southern Texas use agricultural culverts in
cotton fields as roost sites, which may increase their risk of exposure to agricultural
chemicals, either through ingestion of contaminated prey or through dermal exposure to
agricultural runoff.
Simulation modeling was used to characterize the risks to individual burrowing
owls wintering in agricultural landscapes in southern Texas due to effects of exposure to
insecticides or other agricultural chemicals. The simulation model was created using
Stella® VII software (High Performance Systems, Inc., New Hampshire, USA). The
model is broken into four submodels simulating (1) foraging behavior of burrowing owls, (2) chemical applications to crops, (3) chemical transfer and fate in the crop soil
and prey items, and (4) chemical exposure in the burrowing owl.
This model was used to evaluate (1) which components of the model most affect
the endpoints, (2) the relationship between increased concentrations of agricultural
chemicals in culverts and subsequent lethal and sublethal effects from dermal exposure
to agricultural runoff, and (3) which agricultural chemicals have the greatest potential to
cause adverse effects in burrowing owls. Model results suggested (1) the half-lives of
agricultural chemicals in birds caused the most variation in the results, and data gaps
exist for several important model components (2), exposure to increased concentrations
of agricultural chemicals in culverts is unlikely to result in lethal effects, but is likely to
lead to sublethal effects in burrowing owls, and (3) the chemicals with the greatest
potential to negatively affect burrowing owls wintering in southern Texas are the OP
insecticides chlorpyrifos, dicrotophos, and disulfoton, the oxadiazine insecticide
indoxacarb, the herbicide trifluralin, and the defoliants tribufos and paraquat. The results
of this model demonstrate the usefulness of simulation modeling to guide future research
related to the conservation of burrowing owls.
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Migratory behavior of the elf owl (Micrathene whitneyi)Tellez, Carol Ann Mead, 1940- January 1968 (has links)
No description available.
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The small mammal component of the Gottschall Rockshelter (47Ia80) : environmental reconstruction and an analysis of possible owl/raptor influenced taphonomic processes /Brand, Robert J. January 2007 (has links)
Thesis (B.S.)--University of Wisconsin -- La Crosse, 2007. / Also available online. Includes bibliographical references.
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Mexican Spotted Owl reproduction, home range, and habitat associations in Grand Canyon National Park /Bowden, Timothy Scott. January 2008 (has links) (PDF)
Thesis (MS )--Montana State University--Bozeman, 2008. / Typescript. Chairperson, Graduate Committee: Mark L. Taper. Includes bibliographical references (leaves 60-68).
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Mexican Spotted Owl reproduction, home range, and habitat associations in Grand Canyon National ParkBowden, Timothy Scott. January 2008 (has links) (PDF)
Thesis (MS )--Montana State University--Bozeman, 2008. / Typescript. Chairperson, Graduate Committee: Mark L. Taper. Includes bibliographical references (leaves 60-68).
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Determining the ecological status and possible anthropogenic impacts on the grass owl (Tyto capensis) population in the East Rand Highveld, Gauteng.Ansara, Tahla 11 September 2008 (has links)
With the increase in the number of fast-moving vehicles and the simultaneous development of road building technology, roadside bird mortality has become an increasingly important environmental issue that has the potential to do serious damage to already vulnerable bird populations. This project was therefore initiated after an alarming number of owls were found dead along the N17 and R550 roads in the rural areas between Springs and Devon in the East Rand highveld of Gauteng Province. Five hundred and fifty four owls of four species, namely Marsh Owls, the Red Data listed Grass Owl, Barn Owl and the Spotted Eagle Owl were collected on the stretches of the R550 and N17 during the period between October 2001 and September 2003. They accounted for 53.6%, 27.4%, 17.5% and 1.3% of the mortalities respectively. Unidentified species of owls accounted for the remaining 0.2%. It was found that the monthly mortality rates of the birds varied throughout the year, with the greatest losses being suffered during July, as opposed to relatively lower mortalities occurring during the warmer months. All carcasses were collected, their GPS locations plotted on a map, and ‘hotspot areas’ identified as places of highest incidences of mortalities of the owls. Vehicle-induced mortalities are then discussed in relation to these hotspots, in terms of vegetation and habitat descriptions, daily vehicle counts along the route, as well as fixtures found along the route. It was found that traffic density was indirectly proportional to owl mortalities, with higher traffic speeds definitely having an increasingly detrimental effect on the owl mortalities. Weather conditions also play a role in mortality counts, with the mortalities being significantly negatively correlated to rainfall. Moon phases were also related to the times of highest mortalities, however, this factor did not play a significant role in influencing road mortalities. Another factor that was studied was the influence of differing tarmac road surface temperatures as opposed to gravel road verge surface temperatures, and how these temperatures differed from the ambient temperature. It was found that there was not a big enough difference in the temperatures that would warrant (the previously thought notion) that the owls were attracted to the roads at night to gain heat. Gravel roads had very low incidences of owl mortalities with the highest mortalities recorded along tarmac roads that are bordered by open grasslands or cattle grazing paddocks. It was shown that tarmac roads, bordered by croplands, had a lesser effect on the owl mortalities. Another factor influencing the road mortalities of the owls is grain that is spilled on the road during transport. This initially seemed to be the major factor in attracting granivorous rodents to the roads, and in turn, attracting the owls to prey on them. Rodents identified from recovered pellets and the stomach contents of dead owls confirmed the fact that the majority of rodent prey items were indeed granivorous species, namely Mastomys natalensis and Rhabdomys pumilio. This is in disagreement with previous studies that indicated that a large proportion of the prey species of the Grass Owl was Otomys irroratus, a grass-eating species, even though a rodent trapping study to determine prey abundance within the area indicated a healthy population of O. irroratus. Further studies into prey items of the owls that were dissected indicated that the majority of the prey items recovered were not caught directly on the road as it was already partially digested, suggesting that the prey was caught prior to the owl being killed. From the pellet analyses, other prey items were also found to form part of the owls’ diets. It was found that insects formed largely the diet of the Marsh Owl during the spring, summer and autumn months, with them resorting to smaller rodents during the winter months. Spotted Eagle Owls also preyed almost exclusively on insects. Grass Owls, on the other hand, preyed on small mammals exclusively, with the very rare exception of some insects also being taken. Of all of the dead owls recovered on the roads, post mortems were carried out on only 78 of the carcasses. All of the dead owls examined were in good health prior to death. Various morphometrics of the examined owls were noted. Comparisons of body mass showed that females were larger than males for most species. This was also found for most other measurements as well. It was also found that, according to body mass comparisons, Barn Owls and Marsh Owls were significantly similar. Conducting ANOVA analysis on other morphometrics to determine gender differences, it was found that Grass Owl males were significantly different to females in terms of body mass and length. Marsh Owl males were significantly different to females in terms of body mass and tail length; with Barn Owl males being significantly different in terms of tarsus length to females. Except for Spotted Eagle Owl tarsus lengths all other measurements were in favour of females being significantly larger. These findings were also confirmed when applying the Dimorphism Index to all morphometrics measurements, especially body mass. The degree of parasite infestation was also studied during post mortem examinations. Very few cestodes and nematodes were found, with too few to have an effect on the overall health of the birds prior to death. The vegetation type was studied at transects that coincided with hotspot and non-hotspot sites. Using the PRIMER statistical software package, hotspot sites were found to have highest plant cover and diversity, whereas nonhotspot sites showed lowest plant cover and diversity, generally dominated by Hyparrhenia hirta. During these studies, the degree of available nesting habitat was determined and nesting sites were identified, using the ropedragging technique to flush out roosting and nesting owls that would otherwise have been impossible to find in the thick cover. It was found that Grass Owls preferred a habitat rich in thick grass cover that was relatively high (0.75 m–1 m). It was found that the grass species preferred by these owls were Eragrostis curvula, Paspalum sp., Setaria sp., Sporobolis sp., with few other small herbaceous plants. Marsh Owls, on the other hand, seemed not to be too partial regarding roosting and nesting sites, with them roosting and breeding in more mixed vegetation grasslands that had sparser cover, not reaching the height of the grass cover typical of the habitat preferred by the Grass Owls. Opposed to this were the non-hotspot vegetation sites. These sites were found to have vegetation cover unsuited to both the Marsh and Grass owls, with mixed H. hirta grassland not forming the dense cover, or the height, needed by those two species of owls. Foraging owls were also observed, with the vegetation type in the immediate vicinity noted. Vegetation types similar to breeding areas were noted in these foraging areas. Habitat preferences as well as breeding performance were noted for both grassland species of owls, and found to be directly related to land usage in terms of varying agricultural practices and regimes. Fallow, undisturbed lands were found to be highly productive for the owls. Lands planted with Eragrostis sp. were also found to be very productive, but only if left undisturbed for a period of time sufficient to allow the grassland owls to colonise it. Maize-planted fields were found to be utilised only as foraging fields and no breeding of owls was found to take place close to these fields. After extensive nest searching, it was found that both Marsh and Grass owls were breeding from late March to early June, with the Barn Owls breeding in October and again in March. Grass Owls occur in the study area because of the presence of a natural corridor of suitable habitat that runs parallel with the Blesbokspruit. This favourable habitat of the study area is thus conducive to high population density of grassland owls utilising these uncultivated patches of dense and tall vegetation. The high incidence of mortalities on the road in the study area is due to the concomitant high population densities. This healthy population seems to be sustaining the losses occurring on roads. Owls also seem to be gathering in larger numbers in hotspot zones because of the easy available prey, which are attracted to these high productive areas. Agricultural practices in the area lead to the spillage of grain on the road during transportation. Potential prey species foraging on the roads expose themselves to the nocturnal hunters offering an easy dinner. This process leaves these owls vulnerable to vehicle collisions. The overall population size may be larger than previously thought, not with standing the high mortalities already recorded. The small patches of viable habitat in the study area remains suitable for the breeding of the two grassland owl species allowing for such high densities to occur in the area. The Grass Owl, nonetheless, remains severely threatened as it already occurs as a high priority species for conservation concern in the Gauteng Province. This study provides the first assessment of this owl species of this scale in South Africa and this will ultimately promote the long-term survival of these owls. / Dr. V. Wepener
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