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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Psittacidae, a monograph of the parrot family

Guinn, David S. January 1972 (has links)
The design of this study was a random assignment of subjects to the control and the experimental groups, treatment given to the experimental group, and the collection of data from five post tests on both groups. The five post tests were evaluations of the subjects bys clients, peers, supervisors, faculty, and self-evaluations. There was an elapse of at least nine weeks from the time the experimental group received the treatment and the collection of the data on the control and the experimental groups. The instruments used in testing the main hypothesis was the Client Evaluation Inventory and the Counselor Evaluating Rating Scale. The Student's t was the main statistical analysis employed to test the main hypothesis.
2

Delineating pattern and process in tropical lowland : mealy parrot migration dynamics as a guide for regional conservation planning /

Bjork, Robin D. January 1900 (has links)
Thesis (Ph. D.)--Oregon State University, 2005. / Printout. Includes bibliographical references. Also available on the World Wide Web.
3

On the behavioural ecology and vocal communication of the brown-headed parrot (Poicephalus cryptoxanthus)

Taylor, Stuart. 13 December 2013 (has links)
The Brown-headed Parrot (Poicephalus cryptoxanthus) is a poorly known species inhabiting open woodland in south-eastern Africa. This study elucidates critical aspects of the species ecology and although each of these categories impinge on one another, it concentrates on two broad biological aspects, diet and breeding biology, and vocalizations. The species has a generalist diet, switching from one suite of food species to another as and when those species become available, with no species critical for its survival. Analysis of dietary items throughout the year and comparison with handling times and availability reveals that at no time is the species under dietary constraint. Evidence from association indices and behavioural observation shows that the popular view that the Brown-headed Parrot forms pairs just before breeding is erroneous. Birds retain pair bonds and the bond is long-term, lasting at least throughout the year. Congregations are therefore of a classical fission/fusion type with the sub-units being the paired males and females. A mathematical model of the growth of captive chicks is presented, as a guideline to alert potential breeders of Brown-headed Parrots of malnutrition or disease. The species is a secondary cavity hole nester and whilst, the breeding biology of the species is summarised, the importance of large and old trees for breeding opportunities of the species is emphasised. This theme is continued by testing various adaptive hatching hypotheses as possible explanations of asynchronous hatching in the species. It is suggested that asynchronous hatching may be an adaptive strategy moderating against the number of suitable nesting cavities. The vocalization repertoire of the Brown-headed Parrot is described and seven separate vocalizations are recognized. None of these are associated with sexual situations, offering further evidence of a long-term pair bond. Evidence is offered that Brown-headed Parrot chicks can recognise their parents from individual vocal signatures supporting previous evidence from a number of species where chicks may mingle with unrelated chicks. Conversely, parents seem to be unable to recognise their chicks in the same way. It is concluded that this inability may be a result of strong one-way selection pressure, where the costs outweigh the benefits for parents with more than one chick or may be related to the experimental design. Individual recognition by voice implies individual voice differences and the adult double chip contact call is analysed using multivariate statistical techniques. The analysis separates individuals on the basis of frequency and temporal patterns and it is concluded that these parameters may allow individual voice differentiation. Finally, high frequency aspects of the double chip contact call are examined. These frequencies lie above the normally accepted upper threshold of avian hearing. From laboratory and field experiments, behavioural evidence is presented suggesting that the Brown-headed Parrot reacts to these frequencies and may use their degradation as a means of ranging distances to conspecifics. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 2002.
4

Studies of beak and feather disease virus infection /

Khalesi, Bahman. January 2007 (has links)
Thesis (Ph.D.)--Murdoch University, 2007. / Thesis submitted to the Division of Health Sciences. Includes bibliographical references (p. 124-143).
5

Endangered bird species in South Australia : are current recovery practices for the Orange-bellied parrot and Kangaroo Island glossy black cockatoo succeeding? /

Klövekorn, Henning Andreas. January 1998 (has links) (PDF)
Thesis (M. Env. Sc.)--University of Adelaide, Mawson Graduate Centre for Environmental Studies, 1999. / Includes bibliographical references (leaves 108-113).
6

Stable isotope analyses of African grey parrots: a forensic isotope approach

Alexander, Jarryd January 2016 (has links)
A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of requirements for the degree of Master of Science. Johannesburg, 2016. / Stable isotope analyses have been used to infer diets of organisms, define trophic partitioning, and infer geographic origins of species. It has further been applied to forensic ecology to infer the origins of deceased humans and illegally traded animal (elephant ivory and rhinoceros horn) and plant (cycads, coca, and cannabis) material. However, no research has focused on the isotope analysis of avian material in forensic ecology. African grey parrots Psittacus erithacus are one of the most traded species in the world, with the trade often being illegal, and the origins of confiscated or deceased specimens being unknown. The aim of this study was to determine if stable isotopes (δ 13C, δ 15N, and δ 2H) in African grey parrot feathers could be used to determine the wild or captive origins of birds. African grey parrot feathers (primary, body, and tail) differed isotopically so standardising isotope values of African grey parrot feathers to a single feather type was recommended, to maintain consistent sampling and allow for comparisons to be drawn between different feather types. African grey parrot feathers from unknown origins can be identified as wild or captive using δ 13C and δ 2H values, but not δ 15N values. Known wild and captive feathers possibly differ isotopically from one another because of dietary and location differences. Wild African grey parrots inhabit and feed in isotopically depleted C3 forests compared to captive African grey parrots which are usually fed C4 based foods with more positive isotope values. Wild African grey parrot δ 2H isotope values were the most negative in the central region of their native distribution. The ability to differentiate wild from captive African grey parrots, as well as infer basic origins (East from West Africa) may improve the monitoring of the illegal trade as well as help in tracing illegally traded parrots. / LG2017
7

Biology of the greyheaded parrot Poicephalus fuscicollis suahelicus Reichnow.

Symes, Craig Thomas. 30 October 2013 (has links)
This study was conducted to investigate the biology of the Greyheaded Parrot Poicephalus fuscicollis suahelicus in the wild. Field work was conducted in north-east South Africa in the southern limit of the range of the Greyheaded Parrot during two field seasons. Observations from August to December 1999 in the Levubu region, south of the Soutpansberg mountain range, included months of the non-breeding season when Greyheaded Parrots occur seasonally in the area. Observations in the Luvhuvhu-Mutale river confluence area from March to August 2000 included months of the breeding season. No field work was conducted from January to March 2000 due to exceptionally high rains in the southern African sub-region, that prevented access to sites. The Greyheaded Parrot has a widespread distribution, through southern, south Central and East Africa, that has possible changed little in recent years. However, local populations are likely to have suffered extinctions due to habitat destruction and capture for the illegal trade. Populations in protected areas (Makuya Park and Kruger National Park) are less vulnerable to capture than unprotected areas. The conservation of the Greyheaded Parrot outside of protected areas is highlighted. In various parts of the range of the Greyheaded Parrot seasonal movements occur in response to food and nest site availability. Nest sites are possibly limiting in certain parts of its range due to habitat destruction. During post-breeding flocking, the occurrence of larger flocks, possibly family units (mean ± S.E = 4.7 ± 0.2), is common, when birds wander in search for seasonally available food sources. During this period density of Greyheaded Parrots is 0.28 birds/100 ha. Monogamous pairs are more conspicuous during the breeding season (mean ± S.E = 2.1 ± 0.1) and density estimates are 0.14 birds/100 ha. Egg laying is synchronous between pairs with the timed appearance and flocking of juvenile flocks in spring (August/September). Breeding during the dry season reduces competition with other large cavity nesting bird species. Observations suggest that a skewed sex ratio exists in the population (males:females = 2:1). Daily movements are characterised by a bimodal activity pattern. Early morning movements involve flights to activity centres where the accumulation of numerous smaller flocks occur. Here preening, allo-preening and socializing occur with drinking and/or feeding occurring if food and/or water are available. Thereafter, birds move to regular feeding sites, to feed. Activity is decreased during the heat of the day with birds sleeping, resting and/or preening in the canopies of trees. Late afternoon activities involve increased levels of activity and late afternoon return flights to roosts. Greyheaded Parrots are specialist feeders, accessing the kernel of predominantly unripe fruit. This feeding strategy reduces competition with other frugivore competitors. During any one time few tree species are fed on by the Greyheaded Parrot. Greyheaded Parrots were also observed feeding on bark in the breeding season. Two, almost fully fledged, chicks were found dead in a nest and the causes of death undetermined. Their crops contained numerous pieces of masticated bark and insect parts. Behaviours and vocalizations of the Greyheaded Parrot were similar to that recorded in the Cape Parrot. Recognition of the Greyheaded Parrot as a separate species based on species specific calls and DNA warrants further investigation. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2001.
8

Analysis of avian 'speech' : patterns and production

Scanlan, James Patrick January 1988 (has links)
No description available.
9

Comparative cognition and behavioural flexibility in two species of neotropical parrots

van Horik, Jayden Owen January 2014 (has links)
Similarities in brain size, life histories, psychology and behaviour in parrots, corvids and apes suggest that certain socio-ecological selection pressures may have driven the convergent evolution of cognition in these families. However, very little is known about parrot behaviour and cognition, outside of African greys and kea. Therefore, captive red-shouldered macaws (Diopsittaca nobilis) and black-headed caiques (Pionites melanocephala) were presented with a variety of tasks to assess their social and physical cognition and behavioural flexibility. Although these species possess many similarities in their life history and ecology, there are also substantial differences in their morphology and natural habitats that could have driven differences in their cognitive evolution. Observations of social and physical interactions in both species revealed that macaws engaged in high levels of affiliative behaviour, and object neophobia, whereas caiques displayed high levels of social play and object exploration. However, such differences did not appear to result in differences in their social or physical cognition. Macaws and caiques displayed comparable performances on Serial Reversal Learning tasks (as an index of behavioural flexibility). Both species also demonstrated similar performances on two Means-End transfer tasks and a series of innovative foraging tasks that were designed to assess their comprehension of object relationships. However, macaws and caiques appeared to solve such problems by generalising learned information across novel tasks. Overall, these findings suggest that these two species may approach certain socio-ecological problems using flexible cognition that may be generalised across different problems, supporting claims for a domain general intelligence.
10

Psittacid herpesvirus associated with internal papillomatous disease and other tumors in psittacine birds

Styles, Darrel Keith 01 November 2005 (has links)
Internal papillomatous disease (IPD) is characterized by mucosal papillomas occurring primarily in the oral cavity and cloaca of Neotropical parrots. These lesions can cause considerable morbidity, and in some cases result in mortality. Efforts to demonstrate papillomavirus DNA or proteins in the lesions have been largely unsuccessful. However, increasing evidence suggests that mucosal papillomas may contain psittacid herpesviruses (PsHVs). In this study, PsHV 1 genotype 1, 2, and 3 DNA was found in 100% of mucosal papillomas from 30 Neotropical parrots by PCR using PsHV specific primers. However, Psittacus erithacus papillomavirus and finch papillomavirus DNA were not detected. Additionally, a novel PsHV sequence related to, but phylogenetically distinct from PsHV 1, was identified in 4 African grey parrots (Psittacus erithacus), two of which exhibited papillomas. These findings suggest that mucosal papillomas may develop in parrots latently infected with PsHV. Tumors of the bile and pancreatic ducts have also been observed in parrots with IPD. Other mucosal tumors including carcinomas of the proventriculus and ventriculus may be coincident with bile duct tumors, but cloacal carcinomas usually develop as solitary lesions. To test whether PsHV was associated with these tumors, the fresh tissues from 11 parrots and the formalin-fixed paraffin-embedded (FFPE) tissues of 5 parrots exhibiting mucosal tumors were examined by PCR. All tumors were found to contain PsHV 1 genotype 3 DNA except one bird with a cloacal carcinoma that contained genotype 4. Histologically normal tissues available from six parrots did not contain PsHV DNA. Experiments were performed using the FFPE tissues of 5 parrots with IPD related tumors known to contain PsHV by PCR, to show that the virus was in significantly higher concentration in the neoplastic tissue compared to adjacent histologically normal tissue. Neoplastic and adjacent unaffected cells were dissected from the tissues using laser capture microdissection and the DNA was examined by PCR. In situ hybridization using PsHV specific probes and direct in situ PCR were also performed on the tissues. A strong association was shown between infection by PsHV 1 genotype 3 and birds manifesting IPD related tumors and other neoplasms of the digestive tract.

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