Academic literature on the topic 'Grey parrots'
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Journal articles on the topic "Grey parrots"
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Tamungang, Simon A., Robert A. Cheke, Gilbert Z. Mofor, Richard N. Tamungang, and Fritz T. Oben. "Conservation Concern for the Deteriorating Geographical Range of the Grey Parrot in Cameroon." International Journal of Ecology 2014 (2014): 1–15. http://dx.doi.org/10.1155/2014/753294.
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The need for information on Grey Parrot distribution and vegetation associations for informed management and policy decisions was the basis for this study. A nationwide survey of the Grey Parrot population and habitat status was carried out, using questionnaire and point count methods. From the results, the extent of the contemporary range of the parrots was restricted to Southern Cameroon, which harbours the rainforest. Regional parrot population means ranged from 3,487 parrots in the Littoral to 1,351,275 parrots in the East Regions. The extent of the contemporary range as a percentage of the whole country was 25.4% and as a percentage of the regions with rainforest was 44.5%. The historic range of the bird has been reduced by over 55.5%. Estimated percentage of forest lost per region ranged from 20.4% in the Centre to 57.1% in the East and South Regions. At a global level, Cameroon contributed 9% to the total extent of the range of the Grey Parrot in Africa. The range is increasingly fragmented, contracted, and lost through land-based socioeconomic activities. These degradation pressures on the range called for urgent conservation considerations for long-term survival of the parrot species and its associated biodiversity in Cameroon.
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Valle, Simon, Nigel J. Collar, Martim Melo, and Stuart J. Marsden. "What can the abundance of Grey Parrots on Príncipe Island tell us about large parrot conservation?" Journal of Tropical Ecology 36, no. 6 (2020): 293–97. http://dx.doi.org/10.1017/s0266467421000031.
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AbstractWhile populations of the Endangered Grey Parrot Psittacus erithacus have collapsed across its range, the species remains remarkably abundant on the island of Príncipe, Gulf of Guinea. We examine how aspects of its ecology interplay with local environmental conditions, to inform conservation strategies for this species and other large parrots. On Príncipe, parrots breed in large trees of common species, with nest densities (42 ± 34 km−2) greatly exceeding those for any comparably sized parrot. Productivity is high (1.9 chicks per cavity), probably reflecting the absence of nest competitors and predators. Food sources are abundant and much of the island is inaccessible to trappers, so many nests are successful each year. Historically harvest has involved taking only chicks from trees in a few traditional patches. These conditions have combined to allow Grey Parrots to thrive on Príncipe, while elsewhere nest trees are timber targets, nest competition and nest predation are likely to be more intense, trapping is indiscriminate, and few areas remain unexploited by trappers. Preservation of large trees as breeding refugia, and vigilance against the indiscriminate trapping of adult birds, are identified as key conditions to stabilize and recover mainland Grey Parrot populations and indeed large parrots generally, given their very similar ecological traits and anthropogenic circumstances.
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Costa, Pierluca, Elisabetta Macchi, Emanuela Valle, et al. "An association between feather damaging behavior and corticosterone metabolite excretion in captive African grey parrots (Psittacus erithacus)." PeerJ 4 (September 13, 2016): e2462. http://dx.doi.org/10.7717/peerj.2462.
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BackgroundAfrican grey parrots (Psittacus erithacus) are kept as pets and are frequently hand-reared. It has been observed that hand-reared African grey parrots may develop behavioral disorders such as feather damaging behavior (FDB). It is well known that chronic stress is involved in behavioral disorders in captive parrots. The main glucocorticoid in birds is corticosterone; its quantification provides information about adrenocortical activity and is considered to be a reliable indicator of stress levels in birds. We analyzed the differences in the excretion of corticosterone metabolites (CM) in the droppings of African grey parrots characterized by: 1. different rearing histories (parent rearing vs. hand rearing); and 2. the presence or absence of FDB in hand-reared parrots.MethodsA total of 82 African grey parrots that were kept in captivity were considered. According to breeding methods, three groups of birds were defined: 1. The parent-reared (PR) parrots included birds kept in pairs (n= 30 pairs) with a conspecific partner of the opposite sex. All of these birds were healthy and never showed FDB signs; 2. The healthy hand-reared parrots (H-HR) included pet parrots individually kept, that were hand-reared and did not display any sign of FDB (n= 11, 7 males and 4 females); 3. The FDB hand-reared parrot (FDB-HR) included pet parrots individually kept, that were hand-reared and displayed FDB (n= 11, 7 males and 4 females). Droppings were collected in the morning over three alternating days in autumn 2014 and spring 2015. The CM were determined using a multi-species corticosterone enzyme immunoassay kit. Split-plot repeated-measure ANOVA was used to examine any differences using group, season and group × season as the main factors.ResultsDifferent quantities of CM in droppings were found for the three groups. The mean CM value was 587 ng/g in the PR parrots, 494 ng/g in the H-HR parrots and 1,744 ng/g in the FDB-HR parrots, irrespective of the season. The excretion of CM in FDB-HR was significantly higher than in PR or H-HR parrots. CM in droppings were not influenced by the season (autumn vs. spring); furthermore, the interaction between group and sampling season was not significant. Limited to the H-HR and FDB-HR groups, a trend in the significance of the difference in the mean CM excreted by male and female birds was observed, with the levels excreted by males being higher than those excreted by females. When the effect of age was considered (in the two separate groups), there was a statistically significant positive correlation only for H-HR.ConclusionsThe highest amount of CM excretion was found in FDB-HR parrots, and a positive correlation between age and CM excretion was found in H-HR. Given that the CM excretion of both PR and H-HR parrots was similar in our study, future research is recommended to investigate the specific aspects of hand-rearing to improve parrot welfare.
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Gupfinger, Reinhard, and Martin Kaltenbrunner. "The Design of Musical Instruments for Grey Parrots: An Artistic Contribution toward Auditory Enrichment in the Context of ACI." Multimodal Technologies and Interaction 4, no. 2 (2020): 16. http://dx.doi.org/10.3390/mti4020016.
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One particular approach in the context of Animal Computer Interaction (ACI) is auditory enrichment for captive wild animals. Here we describe our research and the methodology used to design musical instruments and interfaces aimed at providing auditory enrichment for grey parrots living in captivity. The paper is divided into three main phases: a project review and classification, sonic experiments at the parrot shelter and the design of musical instruments. The overview of recent projects that involve animals in the interaction and music-generation process highlights the costs and benefits of projects of this kind and provides insights into current technologies in this field and the musical talents of animals. Furthermore, we document a series of sonic experiments conducted at a parrot shelter to develop acoustically enriched environments through the use of musical instruments. These investigations were intended to provide a better understanding of how grey parrots communicate through sound, perceive and respond to auditory stimuli and possibly generate sound and music through the usage of technological devices. Based on the cognitive, physiological, and auditory abilities of grey parrots, and their intrinsic interest in sonic and physical interactions, we finally developed and tested various interactive instrument prototypes and here we present our design results for auditory enrichment in the context of ACI and artistic research.
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DUEKER, SASCHA, DENIS KUPSCH, SERGE KADIRI BOBO, ECKHARD W. HEYMANN, and MATTHIAS WALTERT. "Congo Grey Parrot Psittacus erithacus densities in oil palm plantation, agroforestry mosaic and protected forest in Southwest Cameroon*." Bird Conservation International 30, no. 1 (2019): 156–67. http://dx.doi.org/10.1017/s0959270919000194.
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SummaryThe Congo Grey Parrot Psittacus erithacus has experienced a severe population breakdown in recent decades. The rainforests of the Korup region in Southwest Cameroon may harbour a large population of this species, but density and population estimates from this area remain controversial. Before the 2016 breeding season, we surveyed Grey Parrots along transects (621.1 km survey effort) in three adjacent landscape types: primary forest in Korup National Park (KNP), smallholder agroforestry matrix (AFM), and industrial oil palm plantation (OPP). We also collected information on the trees used for nesting, feeding and roosting. Using Distance analysis, we estimated relatively low densities of stationary flocks, ranging from 0.30 ind./km2 in KNP, over 0.82 ind./km2 in OPP to 2.70 ind./km2 in the AFM. Parrots were observed feeding or roosting in 17 tree species, of which 15 were located in AFM alone. Feeding was most often observed on cultivated Elaeis guineensis and Dacryodes edulis, but never in maize. The detected parrot densities probably reflect declines within the period 2008–2016, suggesting that the species’ recent IUCN uplisting to ‘Endangered’ and transfer to CITES Appendix I was indeed justified. Our results also suggest that traditional smallholder agroforestry may play a role in habitat conservation strategies, since these forms of cultivation may maintain important breeding and feeding opportunities for Congo Grey Parrots.
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Harkinezhad, Taher, Kristel Verminnen, Caroline Van Droogenbroeck, and Daisy Vanrompay. "Chlamydophila psittaci genotype E/B transmission from African grey parrots to humans." Journal of Medical Microbiology 56, no. 8 (2007): 1097–100. http://dx.doi.org/10.1099/jmm.0.47157-0.
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Thirty-six birds from a parrot relief and breeding centre, as well as the manager, were examined for the presence of Chlamydophila psittaci. In the relief unit, 5 of 20 African grey parrots showed depression, ruffled feathers, loss of weight and mild dyspnoea. The birds received no antibiotic treatment. Birds of the breeding unit, 14 blue and gold macaws and 2 green-winged macaws, were healthy. They received doxycycline at the start of each breeding season. The manager complained of shortness of breath but took no medication. Using a nested PCR enzyme immunoassay (EIA), Cp. psittaci was detected in the faeces of all five sick birds, as well as in a nasal and pharyngeal swab from the manager. The veterinarian and her assistant became infected while sampling the parrots, as pharyngeal and nasal swabs from both were positive by nested PCR/EIA after visiting the parrot relief and breeding centre, but they showed no clinical signs of infection. Bacteria could be isolated from three of five nested PCR/EIA-positive birds, the manager and the veterinarian, but not from the veterinary assistant. Using an ompA genotype-specific real-time PCR, Cp. psittaci genotype E/B was identified as the transmitted strain. All breeding birds tested negative for Cp. psittaci. This is believed to be the first report on Cp. psittaci genotype E/B transmission from parrots to humans. In contradiction to genotype A strains, which are thought to be highly virulent to both birds and men, the currently described genotype E/B strain apparently caused no severe clinical symptoms in either parrots or humans.
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Marsden, Stuart J., Emmanuel Loqueh, Jean Michel Takuo, et al. "Using encounter rates as surrogates for density estimates makes monitoring of heavily-traded grey parrots achievable across Africa." Oryx 50, no. 4 (2015): 617–25. http://dx.doi.org/10.1017/s0030605315000484.
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AbstractEstimating population sizes in the heavily traded grey parrots of West and Central Africa would provide insights into conservation status and sustainability of harvests. Ideally, density estimates would be derived from a standardized method such as distance sampling, but survey efforts are hampered by the extensive ranges, patchy distribution, variable abundance, cryptic habits and high mobility of the parrots as well as by logistical difficulties and limited resources. We carried out line transect distance sampling alongside a simpler encounter rate method at 10 sites across five West and Central African countries. Density estimates were variable across sites, from 0–0.5 individuals km−2 in Côte d'Ivoire and central Democratic Republic of the Congo to c. 30 km−2 in Cameroon and > 70 km−2 on the island of Príncipe. Most significantly, we identified the relationship between densities estimated from distance sampling and simple encounter rates, which has important applications in monitoring grey parrots: (1) to convert records of parrot groups encountered in a day's activities by anti-poaching patrols within protected areas into indicative density estimates, (2) to confirm low density in areas where parrots are so rare that distance sampling is not feasible, and (3) to provide a link between anecdotal records and local density estimates. Encounter rates of less than one parrot group per day of walking are a reality in most forests within the species’ ranges. Densities in these areas are expected to be one individual km−2 or lower, and local harvest should be disallowed on this basis.
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Gaspar, H., F. Bargallo, J. Grífols, E. Correia, and ML Pinto. "Haematological reference intervals in captive African Grey parrots (Psittacus erithacus)." Veterinární Medicína 66, No. 1 (2021): 24–31. http://dx.doi.org/10.17221/15/2020-vetmed.
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The African Grey parrot (Psittacus erithacus) is one of the most popular avian pets in exotic animal practice. In this study, blood samples (n = 459) from healthy African Grey parrots (n = 239) were collected for haematological testing. Reference intervals were determined according to the guidelines of the American Society of Veterinary Clinical Pathology with the Reference Value Advisor (v2.1) freeware. The calculated reference intervals (RIs) were: packed cell volume 38–59%; haemoglobin 105–154 g/l; RBC 2.3–3.3 10<sup>6</sup>/µl; MCV 145.5–199.7 fl; MHC 38.3–55.6 pg; MCHC 232–313 g/l; WBC 2.7–12.6 10<sup>3</sup>/µl; heterophils 1.2–10.2 10<sup>3</sup>/µl; lymphocytes 0.8–4.3 10<sup>3</sup>/µl; monocytes 0.0–0.6 10<sup>3</sup>/µl; basophils 0.0–0.1 10<sup>3</sup>/µl; eosinophils 0.0–0.2 10<sup>3</sup>/µl. To the best of our knowledge, this is the first study in psittacines to use such a high number of birds and samples to establish haematological species-specific RIs, providing a valuable tool to professionals dealing with the health of African Grey parrots.
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Brucks, Désirée, Matthew Petelle, Cecilia Baldoni, Anastasia Krasheninnikova, Eleonora Rovegno, and Auguste M. P. von Bayern. "Intra- and interspecific variation in self-control capacities of parrots in a delay of gratification task." Animal Cognition 25, no. 2 (2021): 473–91. http://dx.doi.org/10.1007/s10071-021-01565-6.
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AbstractForgoing immediate satisfaction for higher pay-offs in the future (delayed gratification) could be adaptive in situations that wild animals may encounter. To explain species-differences in self-control, hypotheses based on social complexity, feeding ecology, brain size and metabolic rate have been proposed. To explore these hypotheses in a comparative setting, we tested three macaw species (neotropical parrots)—great green macaws (N = 8), blue-throated macaws (N = 6), blue-headed macaws (N = 6)—and the distantly related African grey parrots (afrotropical parrots; N = 8) in a modified rotating tray task, in which subjects are required to inhibit consuming a constantly available low-quality reward in favour of a high-quality reward that becomes available only after an increasing delay (min. 5 s, max. 60 s). All four species successfully waited for a minimum of 8.3 s ± 11.7 s (group level mean ± SD) with African greys reaching a delay of 29.4 ± 15.2 s, and great green macaws—as best performing macaw species—tolerating delays of 20 s ± 8 s. The best performing African grey individual reached a maximum delay of 50 s, whereas, a great green and a blue-throated macaw tolerated a delay of 30 s max. Females tolerated higher maximum delays than males. Engaging in distraction behaviours enhanced waiting performance across species and all birds were able to anticipate the waiting duration. Our results suggest that both feeding and socio-ecological complexity may be a factor in self-control, but further systematically collected comparative data on self-control of different (parrot) species are required to test the evolutionary hypotheses rigorously.
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Schloegl, Christian, Judith Schmidt, Markus Boeckle, Brigitte M. Weiß, and Kurt Kotrschal. "Grey parrots use inferential reasoning based on acoustic cues alone." Proceedings of the Royal Society B: Biological Sciences 279, no. 1745 (2012): 4135–42. http://dx.doi.org/10.1098/rspb.2012.1292.
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Our ability to make logical inferences is considered as one of the cornerstones of human intelligence, fuelling investigations of reasoning abilities in non-human animals. Yet, the evidence to date is equivocal, with apes as the prime candidates to possess these skills. For instance, in a two-choice task, apes can identify the location of hidden food if it is indicated by a rattling noise caused by the shaking of a baited container. More importantly, they also use the absence of noise during the shaking of the empty container to infer that this container is not baited. However, since the inaugural report of apes solving this task, to the best of our knowledge, no comparable evidence could be found in any other tested species such as monkeys and dogs. Here, we report the first successful and instantaneous solution of the shaking task through logical inference by a non-ape species, the African grey parrot. Surprisingly, the performance of the birds was sensitive to the shaking movement: they were successful with containers shaken horizontally, but not with vertical shaking resembling parrot head-bobbing. Thus, grey parrots seem to possess ape-like cross-modal reasoning skills, but their reliance on these abilities is influenced by low-level interferences.
Dissertations / Theses on the topic "Grey parrots"
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Dennison, D. T. "A nutritional and financial evaluation of breeding African Grey parrots (Psittacus erithacus)." Thesis, Stellenbosch : University of Stellenbosch, 2004. http://hdl.handle.net/10019.1/2768.
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Thesis (MPhil (Animal Sciences))--University of Stellenbosch, 2004.<br>African Grey Parrots are now being bred on a commercial scale in South Africa, mainly for the export market. In order to produce the best breeding results it is necessary to formulate balanced diets but no research has been done on the feeding value for African Grey parrots of ingredients used in formulating diets. Once the apparent metabolisable energy (AME) of extruded maize for African Greys has been established it will be possible to calculate the AME of other ingredients such as full fat soya, soya oil cake or sunflower oil cake. By feeding an extruded mix containing a known amount of maize mixed with a known amount of soya oil cake and establishing experimentally the AME of the mix, the AME of soya oil cake for African Greys can be calculated by difference. This information will make it possible to decide whether AME results obtained for poultry can be used in formulating diets for African Grey parrots.
The study consisted of two parts where the determination of the apparent metabolisable energy (AME) of extruded maize and the practical application thereof in formulating parrot diets, and the economic viability of a commercial African Grey parrot breeding operation was investigated. A reference procedure adopted by several European laboratories for the in vivo determination of metabolisable energy (ME) was used to determine the apparent metabolisable energy (AME) of extruded whole maize for African Grey parrots. The long term goal is to make a well balanced, extruded diet for these birds. Extruded maize is the form in which maize is generally included in commercial parrot diets and was therefore chosen as the experimental feed. Maize can be conveniently extruded with other single ingredients such as full fat soyabean meal, soyabean oil cake meal or sunflower oil cake meal to determine, by difference, the AME of those ingredients. For the first part of the study, ten, 3-year-old African Grey parrots were individually housed and fed in cages designed to facilitate collection of the faeces. Cage design varied between a tall type (n=6) and a low type (n=4). The parrots were acclimatized to their new environment before the trial commenced to ensure normal feeding behaviour.
The average AME value established for the ten African Grey Parrots was 16.8 MJ/kg. In the trial it became apparent that it is very difficult to get consistent results with the cages used and a modified cage design is proposed for the future. The second part of the study investigated the economic viability of breeding African Grey parrots commercially, with extruded maize as part of their diet. It was generally concluded that the breeding of African Grey parrots for the pet market can be considered as an economical venture.
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May, Diana L. "The vocal repertoire of grey parrots (Psittacus erithacus) living in the Congo Basin." Diss., The University of Arizona, 2004. http://hdl.handle.net/10150/280626.
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This dissertation is a report on the investigation of the vocal behavior of free-living Grey Parrots (Psittacus erithacus) that inhabit the Congo Basin in Central Africa. I observed Grey Parrots in the Central African Republic and Cameroon and made audio recordings of their vocalizations. The results of spectrographic analysis of vocalizations lend support to the assertion that Grey Parrots produce calls that fall into four major acoustical classes--tonal, harmonic, noisy-harmonic, and noisy--and that these call classes may be subdivided into as many as 39 different acoustical types. A reliability study of this classification scheme demonstrated that both clustering of these acoustical types into aggregate categories and the combined method of visual inspection and basic spectrographic measurement enable reliable classification of calls into classes, types and also subtypes. The majority of calls in the observed repertoire belong to pure tonal call class, which may suggest that a large proportion of Grey Parrot calling behavior is adapted for tonal call production. Grey Parrots may also adjust the acoustic characteristics of their calls to better adapt them to their environment and communication needs. Both observations of Grey Parrots and analysis of the acoustic and production characteristics of their calls indicate that Grey Parrots may share functional call types of some New World and Australian parrot species. Some Grey Parrot calling vocal behavior parallels that of captive Grey Parrots in the laboratory. I conclude with an exploration of possible reasons why Grey Parrots possess such a diverse vocal repertoire.
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Schmid, Rachel. "The influence of the breeding method on the behaviour of adult African grey parrots /." Bern : [s.n.], 2004. http://www.zb.unibe.ch/download/eldiss/04schmid_r.pdf.
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Valle, Simon. "Population viability and conservation of grey parrots (Psittacus erithacus) on the island of Príncipe, Gulf of Guinea." Thesis, Manchester Metropolitan University, 2015. http://e-space.mmu.ac.uk/617952/.
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Parrots are among the most endangered birds in the world, owing to the international pet trade, and habitat degradation. Grey Parrot Psittacus erithacus, the most traded wild-caught species, has suffered a steep decline across its vast African range. This PhD investigates Grey Parrot’s ecology to understand the mechanisms by which harvest and habitat loss affect populations. The island of Príncipe was chosen as a study area owing to its healthy Grey Parrot population, its tradition of parrot harvest and the disturbed-to-pristine range of habitats. Parrot densities were exceptionally high (mean±SE: 53±3 parrots km-1), and their distribution within the island was shown to change significantly between pre- and post-breeding season. The presence of nest tree species was the best predictor of densities in the former (F = 2.99, p = 0.07), while slope and food tree species were in the latter (F = 3.0, p < 0.05 and F = 8.04, p < 0.01). Variation in habitat use across seasons highlights the importance of opportunely timed surveys, and the need of preserving a matrix of habitats. Three simple and inexpensive methods were tested, which may be useful where more precise methods cannot be used. Simple encounter rates were shown to be a workable proxy for actual densities: a relationship was found between the two (R2=0.8, df=9, p=0.01). Long watches proved to be far less accurate and suitable only in limited cases (i.e. enough vantage points overlooking small areas and numerous encounters). Counts along flyways were suggested to be a good monitoring method, although further testing is required. Nest densities were found to be very high (mean±SE: 16.8±7.9 and 72.4±26.2 nests km-2 in secondary and primary forest respectively) compared to those elsewhere. The habitat characteristics measured didn’t affect productivity, suggesting that cavity characteristics may be more important. The best demographic data available on the species, were used to build a Population Viability Model to investigate its population dynamics in the face of harvest and habitat loss. In Príncipe, Grey Parrots were shown to have increased rapidly after a trade ban was put in place, highlighting the recovery potential of the species. Harvest alone was shown to be harmless only when small quotas (e.g. 600 chicks year-1) are yielded from large populations, while habitat loss lowered the predicted maximum population size. The interaction of these threats can be much more unpredictable. The effects of harvest are worsened if poorly regulated or techniques that include the harvesting of adults are used. Extinctions were predicted to occur with significant delay (≥40 years), and the conservation implications were discussed. Finally, the contribution of this thesis to the understanding of Grey Parrots ecology and conservation is highlighted and research priorities identified.
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Zilber-Izhar, Katia. "Acoustic Characteristics of Phonological Development in a Juvenile African Grey Parrot (Psittacus Erithacus) Who Is Learning Referential Speech." Thesis, Harvard University, 2015. http://nrs.harvard.edu/urn-3:HUL.InstRepos:24078346.
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Although young children can sometimes produce words in a near perfect form at a very early stage, several diary studies revealed that these correct first productions are usually followed by less faithful renditions, only to be returned later to relative accuracy. In order to investigate if this nonlinear pattern of children vocal production called “phonological regression” might also be shared with birds, we examined here the trajectory of vocal development of a young African Grey parrot (Athena) who is learning referential English. Parrots are excellent model systems for the study of speech acquisition as they possess advanced cognitive skills and are expert imitators of the human voice. By tracking Athena’s acquisition of vowel-like sounds over the course of fifteen months using audio recordings and acoustic software programs, we analyzed her vocal development over time, from her first squeaks to her more distinct pronunciations, and compared her progress with human children and other parrots in the lab. Not one, but multiple U-shaped curves characterized her acquisition of isolated labels. Our results indicate that, like human children, parrots can experience the phenomenon of phonological regression.
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Annorbah, Nathaniel N. D. "Assessing distribution, abundance and impacts of trade and habitat change in western populations of African grey parrot (Psittacus erithacus)." Thesis, Manchester Metropolitan University, 2016. http://e-space.mmu.ac.uk/617150/.
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In Ghana, many large avian frugivores face very serious threats, including habitat loss, hunting, and capture for the pet trade. However, basic ecological information is lacking for most species including the heavily-traded Grey Parrot Psittacus erithacus. The aim of my PhD was therefore to investigate the current distribution, abundance and ecology of Grey Parrot and other large frugivores to help inform their future conservation. I conducted surveys for twenty species of pigeons, parrots, turacos and hornbills in forty-two 10 km × 10 km survey squares in southwest Ghana. Only two species, West African Pied Hornbill Lophoceros semifasciatus and African Green Pigeon Treron calvus, were recorded in most survey squares. The most restricted and rare species included large-bodied species such as Great Blue Turaco Corythaeola cristata, Yellow-casqued Hornbill Ceratogymna elata and Black-casqued Hornbill C. atrata. Canonical Correspondence Analysis showed that large hornbills were especially restricted to large forest reserves with low anthropogenic disturbance. I then used Maxent to predict more precisely the distribution of the frugivores across Ghana, and identify their responses to predictors such as land cover types, enhanced vegetation index (EVI), human population density, and climate data. Frugivores showed varying associations with Ghana’s large forest reserves, with Afep Pigeon Columba unicincta, Great Blue Turaco, and Black Dwarf Hornbill Tockus hartlaubi among the most restricted. Most species had highest occurrence probabilities in the southwest of the country. The main driver of distributions was land cover type, with forest habitats preferred in 90% of species. Differences in human population density and EVI were seldom important. The large southwestern forest reserves are key sites for Ghana’s frugivores, and it is crucial that they are adequately protected and managed. Grey Parrot is believed to have undergone rapid population decline, yet there are almost no quantitative data properly supporting this from anywhere within its huge range. I reviewed its historical abundance across Ghana, undertook targeted searches across the country’s forest zone, repeated counts at 22 parrot roosts first performed two decades ago and gauged around 900 people’s perceptions of the decline and its causes. In over 150 days of fieldwork, just 32 groups were recorded. Encounter rates were 15 times lower than those from the early 1990s. No active roosts, i.e. roosts in current use, were found, and just a handful of birds seen near three roosts that each harboured 700–1200 birds two decades ago. Interviewees stressed the importance of very tall trees of commercially important timber species for nesting and roosting. Ghana has lost 90–99% of its Grey Parrots since 1992, and there is no evidence that, away from one or two localities, declines are less severe anywhere else in West Africa. Despite declines, Grey Parrots paradoxically remain reasonably widely distributed. I developed multiple historical and current Maxent models for the species based on various presence data sources: field surveys from the early 1990s and 2012–14, records from the Global Biodiversity Information Facility, and interview data. Models of historical distribution showed high suitability over much of the study area. Current distributions were predicted to be much more patchy, with large areas unsuitable, but with high suitability in the extreme south/southwest. Historically, Grey Parrot distribution was correlated most strongly with high rainfall, while current distribution is more closely linked with land use. Levels of exploitation of Grey Parrots have been unsustainable and regulation of the trade through quota schemes and enforcement of trade embargoes needs to be strengthened. Ghana should also reintroduce shade cocoa agriculture to improve habitat quality for the Grey Parrot and other frugivores.
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Alexander, Jarryd. "Stable isotope analyses of African grey parrots: a forensic isotope approach." Thesis, 2016. http://hdl.handle.net/10539/21719.
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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.<br>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.<br>LG2017
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Peng, Yun-Wen, and 彭筠文. "The Relationship between Intra-arterial Pressure and Intra-osseous Pressure in African Grey Parrots (Psittacus erithacus)." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/nhztz8.
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碩士<br>國立臺灣大學<br>臨床動物醫學研究所<br>107<br>Blood pressure is one of the vital signs in clinical medicine, its’ reading provides a direct evaluation of systemic circulation. However, in birds, blood pressure measurement is not performed routinely during physical examination owing to special physiologic, anatomic limitations and inaccuracy of indirect blood pressure measurement in avian patients. Intraosseous catheter is now the most commonly used route in avian fluid therapy, especially for those small sized or are hypotensive that makes the vessel inaccessible. In human medicine, similar limitations were encountered in neonatal or critically illed patients, some research has found that intraosseous catheter can be placed more quickly, easily, and with lower complications. Hence, recently, more and more researches has focused on the relationship between intraosseous pressure and arterial pressure, and try to find if the intraosseous pressure measurement could replace blood pressure measurement in clinical condition
In this study, we used 12 healthy sub-adult or adult African grey parrots (Psittacus erithacus) as experimental subjects. Each bird was maintained under general anesthesia condition, a 24 gauge catheter was installed into the deep radial artery and a 22 guage needle was installed into the ulna medullary cavity respectively. Both catheters connected to a disposable pressure sensor, and arterial pressure waveform and intraosseous pressure waveforms were recorded for 10 minutes. The arterial pressure values were normally distributed while the intraosseous pressure values were not. The average of arterial systolic, mean, diastolic pressure values are 118.90±11.66(94.50-136.02) mmHg, 94.86±17.97(66.89-129.51) mmHg and 79.66±20.42(49.05-117.87) mmHg. The average of intraosseous mean pressure values is 49.17± 29.94(2.03-93.21) mmHg, and the average heart rate is 315.19± 101.14(158.20-490.60) beat per minute. There’s no correlation between arterial pressure values and intraosseous pressure values. A positive relationship between heart rate and mean intraosseous pressure values was found and the correlation coefficient was 0.58.
Though future research may need to determine the efficacy of intraosseous pressure, based on its easier and less time consuming techniques, it is still a potential method for further clinical use in avian patients.
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Lee, Yen-Lin, and 李彥霖. "Determination of enhancement effect and diameters of the major arteries using the dual-headed power injector in CT-A in African Grey parrots." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/41822165814037015684.
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碩士<br>國立臺灣大學<br>臨床動物醫學研究所<br>103<br>Atherosclerosis is probably the most common cardiovascular disease in parrots. Nowadays, ante-mortem diagnosis of atherosclerosis in birds is still difficult. In humans, CT-A has long been used as a non-invasive, sensitive tool to identify calcified and non-calcified plaques in major arteries. At this time, it seems to be a promising method to evaluate the avian cardiovascular system. The objective of our study was to establish the CT-A protocol using the dual-headed power injector in African Grey parrots (Psittacus erithacus) as well as reference range of attenuation value and diameters of the major arteries. 16-slice CT scanning was used to measure the region of interest (ROI) in 6 major arteries. Before scanning, each bird underwent physical, blood, and cardiologic examination and were considered healthy. Each bird was under general anesthesia during CT-A procedure. The dual-headed power injector with saline chaser technique was used to administer contrast medium and saline flush. We used the real-time bolus-tracking method, and triggered the scan manually once the peak enhancement of ascending aorta was reached. The measurements were obtained by 2 clinicians double-blindly. The reference range before and after contrast medium administration via body, pulmonary, and bone window were set up accordingly. Inter-observer consistency in measurements was high in post-contrast values via a body window. Hence, we suggested performing CT-A in parrots with contrast medium administration in body window. However, further studies will be needed to improve the potential and utility of CT-A in diagnosis of atherosclerosis in parrots.
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Colbert-White, Erin Natannie. "An African grey parrot's vocal production varies across social context." 2009. http://purl.galileo.usg.edu/uga%5Fetd/colbert-white%5Ferin%5Fn%5F200905%5Fms.
Full textBooks on the topic "Grey parrots"
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Higdon, Pam. The essential African grey. Edited by Higdon Pam and Mancini Julie R. Howell Book House, 1999.
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Athan, Mattie Sue. The African grey parrot handbook. 2nd ed. Barron's Educational Series, 2009.
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Mulliken, Teresa A. South Africa's trade in African grey parrots. TRAFFIC East/Southern Africa, 1995.
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Homberger, Dominique G. The lingual apparatus of the African grey parrot, Psittacus erithacus Linné (Aves: Psittacidae): Description and theoretical mechanical analysis. The American Ornithologists' Union, 1986.
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Alamutu, Sola. Cate saves the Ikopi rainforest: The action adventures of Cate, the African grey parrot. CATE, 2003.
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Gardiner, Jenny. Winging it: A memoir of caring for a vengeful parrot who's determined to kill me. Simon Spotlight Entertainment, 2010.
Find full textBook chapters on the topic "Grey parrots"
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Pepperberg, Irene M. "Referential Vocal Learning by Grey Parrots." In Encyclopedia of the Sciences of Learning. Springer US, 2012. http://dx.doi.org/10.1007/978-1-4419-1428-6_1709.
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Pepperberg, Irene M. "Emergence of Linguistic Communication: Studies on Grey Parrots." In Emergence of Communication and Language. Springer London, 2007. http://dx.doi.org/10.1007/978-1-84628-779-4_19.
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Pepperberg, Irene M. "Interspecies Communication with Grey Parrots: A Tool for Examining Cognitive Processing." In Biocommunication of Animals. Springer Netherlands, 2013. http://dx.doi.org/10.1007/978-94-007-7414-8_12.
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Pepperberg, Irene M. "Adaptive Behavior and Learning: How Cognitive Processing and Social Interaction Might Affect Allospecific Vocal Learning in Grey Parrots (Psittacus erithacus)." In Prerational Intelligence: Adaptive Behavior and Intelligent Systems Without Symbols and Logic, Volume 1, Volume 2 Prerational Intelligence: Interdisciplinary Perspectives on the Behavior of Natural and Artificial Systems, Volume 3. Springer Netherlands, 2000. http://dx.doi.org/10.1007/978-94-010-0870-9_69.
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Pepperberg, I. M. "Communication in Grey Parrots." In Encyclopedia of Language & Linguistics. Elsevier, 2006. http://dx.doi.org/10.1016/b0-08-044854-2/00829-4.
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Martinho-Truswell, Antone. "PARROTS IN THE MIRROR." In The Parrot in the Mirror. Oxford University PressOxford, 2022. http://dx.doi.org/10.1093/oso/9780198846109.003.0007.
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Abstract This chapter focuses on parrots, looking at three groups that exemplify convergent evolution—and parallel history—with humans: the cockatoos, the grey parrots, and the macaws. Like humans, they represent the extreme edge of what it means to be a parrot, the case where all the evolutionary forces combined to push a species or group of species towards an extreme version of its type. What is remarkable is that these two extreme groups of animals, the humans and the urparrots, have, in their extremity, become so remarkably similar. Rather than each being pushed to opposite ends of what it means to be an animal, they have ended up mirror images of each other, with parrots a whispered answer to the question: what if a different group of animals were to evolve like the humans? The chapter then considers the similarities that humans share with parrots, including longevity and monogamy. Where the parrots truly become our mirror image, however, is in their brains and their language. They share with us learning, fretfulness, personality, and artistry. Laboratory research has confirmed the expert lockpicking ability of these birds as well.
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PEPPERBERG, IRENE M. "Grey parrots: learning and using speech." In Nature's Music. Elsevier, 2004. http://dx.doi.org/10.1016/b978-012473070-0/50016-5.
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Pepperberg, Irene M. "Grey Parrots: A Studies in Avian Cognition." In Encyclopedia of Animal Behavior. Elsevier, 2019. http://dx.doi.org/10.1016/b978-0-12-809633-8.90709-x.
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"Cognitive and Communicative Abilities of Grey Parrots." In The Cognitive Animal. The MIT Press, 2002. http://dx.doi.org/10.7551/mitpress/1885.003.0035.
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"Allospecific Referential Speech Acquisition in Grey Parrots (Psittacuserithacus)." In Imitation in Animals and Artifacts. The MIT Press, 2002. http://dx.doi.org/10.7551/mitpress/3676.003.0005.
Full textConference papers on the topic "Grey parrots"
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Gupfinger, Reinhard, and Martin Kaltenbrunner. "Sonic Experiments with Grey Parrots." In ACI2017: Fourth International Conference on Animal-Computer Interaction. ACM, 2017. http://dx.doi.org/10.1145/3152130.3152137.
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Grammar, Alex W., and Robert L. Williams. "Design of a Robotic Gripper Based on a Psittacus Erithacu Beak." In ASME 2012 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/detc2012-70244.
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A high versatility, low degrees-of-freedom (DOF) gripper was designed based on avian morphology. Grasping mechanisms for robotic manipulators are often developed for application-specific tasks, such as manipulating a single part or performing a repetitive action. In contrast, more dexterous grippers are complex, multiple-DOF mechanisms. A simple, minimal-DOF, versatile gripper has been developed based on the morphology of the Psittacus Erithacu (African Grey Parrot) beak shape. This species is highly intelligent and uses its beak for digging, gripping, climbing, and foraging. Giving a robot a similar capability would allow the platform to pick up targets such as single, small seeds, liquids, large irregular rocks and soft Robocup style balls. By using the beak as a model for a grasping mechanism the design maintains its versatility without the need for a complex system and allows a large range of targets to be gripped. This gripper is intended for use in the new open-source humanoid robot DARwIn-OP.
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Pepperberg, Irene M. "Referential use of American English speech by an African Grey parrot (Psittacus erithacus): phonological output reflects cognitive capacities." In Medical Imaging 1997, edited by Eric A. Hoffman. SPIE, 1997. http://dx.doi.org/10.1117/12.274029.
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