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1.
J Zoo Wildl Med ; 50(2): 427-436, 2019 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-31260210

RESUMO

A group of zoo-housed little penguins (Eudyptula minor) was diagnosed with mycobacteriosis. While undergoing multidetector computed tomography (MDCT) imaging for an unrelated research project, pulmonary lesions were detected in multiple individuals. In general, birds appeared healthy and free of outward signs of disease. After the loss of three individuals, polyclonal mycobacterial disease due to Mycobacterium avium-intracellulare complex was confirmed. Surviving birds were treated with rifampin (45 mg/kg), ethambutol (30 mg/kg), clarithromycin (10 mg/kg), and enrofloxacin (30 mg/kg) compounded into a single capsule administered once a day in food. After 3 mo of therapy, MDCT imaging documented a decrease in nodule size and number in all remaining birds, with further improvement documented after 13 mo of treatment. MDCT imaging was invaluable for diagnosing disease, documenting disease progression over time, and assessing response to therapy. Early initiation of therapy before the development of outward signs of disease led to resolution of mycobacterial pulmonary lesions in multiple penguins. Mycobacterial disease in this group of little penguins, as well as previously published reports, suggests that the species is at increased risk for developing mycobacteriosis.


Assuntos
Antibacterianos/uso terapêutico , Doenças das Aves/microbiologia , Complexo Mycobacterium avium , Infecção por Mycobacterium avium-intracellulare/veterinária , Spheniscidae , Animais , Animais de Zoológico , Doenças das Aves/tratamento farmacológico , Feminino , Masculino , Infecção por Mycobacterium avium-intracellulare/tratamento farmacológico , Infecção por Mycobacterium avium-intracellulare/microbiologia , Infecção por Mycobacterium avium-intracellulare/mortalidade
2.
J Zoo Wildl Med ; 50(2): 396-404, 2019 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-31260206

RESUMO

Multidetector computed tomography (MDCT) scans were performed in clinically healthy, nonanesthetized, standing little penguins (Eudyptula minor) to determine reference ranges for air-sac and lung volumes, as well as lung density. Five of 15 clinically healthy birds were diagnosed with pulmonary granulomas on initial MDCT scans. Granulomas were not readily apparent on radiographs, even in cases where the entire normal pulmonary parenchymal architecture was effaced on the MDCT scan. Serial MDCT scans after antifungal and antimycobacterial therapies demonstrated a response to treatment. MDCT scanning in nonanesthetized little penguins proved to be a well-tolerated, non-invasive imaging modality for respiratory diseases that are otherwise difficult to diagnose, including aspergillosis and mycobacteriosis.


Assuntos
Doenças das Aves/diagnóstico por imagem , Sistema Respiratório/anatomia & histologia , Sistema Respiratório/diagnóstico por imagem , Doenças Respiratórias/veterinária , Spheniscidae , Tomografia Computadorizada por Raios X/veterinária , Sacos Aéreos/anatomia & histologia , Animais , Animais de Zoológico , Feminino , Pulmão/anatomia & histologia , Masculino , Doenças Respiratórias/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos
3.
N Z Vet J ; 65(6): 332-337, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28738733

RESUMO

CASE HISTORY A little penguin (Eudyptula minor) of wild origin, in captivity at Wellington Zoo, became inappetent and lethargic in March 2013. Despite supportive care in the zoo's wildlife hospital, the bird died within 24 hours. CLINICAL FINDINGS Weight loss, dehydration, pale mucous membranes, weakness, increased respiratory effort and biliverdinuria were apparent on physical examination. Microscopic evaluation of blood smears revealed intra-erythrocytic stages of Plasmodium spp. and a regenerative reticulocytosis in the absence of anaemia. PATHOLOGICAL FINDINGS Post-mortem findings included reduced body condition, dehydration, pulmonary congestion and oedema, hepatomegaly, splenomegaly, hydropericardium and subcutaneous oedema. Histopathological findings included protozoal organisms in sections of lung, liver and spleen. A marked, diffuse, sub-acute interstitial histiocytic pneumonia was present. Accumulation of haemosiderin was noted in the Kupffer cells of the liver and in histiocytic-type cells in the spleen. MOLECULAR TESTING DNA was extracted from frozen portions of the liver. Nested PCR results and DNA sequencing confirmed infection of the deceased little penguin with Plasmodium (Huffia) elongatum lineage GRW06. DIAGNOSIS Avian malaria due to Plasmodium (Huffia) elongatum GRW06 RETROSPECTIVE INVESTIGATION A retrospective analysis of 294 little penguin cases in the Massey University post-mortem database revealed three other potential avian malaria cases. Analysis of archived tissues using a nested PCR for Plasmodium spp. followed by DNA sequencing revealed that a little penguin which died at Auckland Zoo was infected with P. elongatum GRW06 and two wild little penguins found dead on New Zealand beaches were infected with P. relictum SGS1 and Plasmodium. sp. lineage LINN1. Therefore, the overall frequency of deaths in little penguins associated with avian malaria was 4/295 (1.36%). CLINICAL RELEVANCE Our results suggest that avian malaria is associated with sporadic mortality in New Zealand's little penguins both in the wild and in captivity, but there is no evidence of mass mortality events due to Plasmodium spp. infection.


Assuntos
Malária Aviária/diagnóstico , Malária Aviária/mortalidade , Spheniscidae , Animais , Animais de Zoológico , Nova Zelândia , Plasmodium , Estudos Retrospectivos
4.
Int J Biometeorol ; 60(8): 1237-45, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26698160

RESUMO

Seabirds are subject to the influences of local climate variables during periods of land-based activities such as breeding and, for some species, moult; particularly if they undergo a catastrophic moult (complete simultaneous moult) as do penguins. We investigated potential relationships between adult penguin survival and land-based climate variables (ambient air temperature, humidity and rainfall) using 46 years of mark-recapture data of little penguins Eudyptula minor gathered at a breeding colony on Phillip Island in southeastern Australia. Our results showed that adult penguin survival had a stronger association with land-based climate variables during the moult period, when birds were unable to go to sea for up to 3 weeks, than during the breeding period, when birds could sacrifice breeding success in favour of survival. Annual adult survival probability was positively associated with humidity during moult and negatively associated with rainfall during moult. Prolonged heat during breeding and moult had a negative association with annual adult survival. Local climate projections suggest increasing days of high temperatures, fewer days of rainfall which will result in more droughts (and by implication, lower humidity) and more extreme rainfall events. All of these predicted climate changes are expected to have a negative impact on adult penguin survival.


Assuntos
Mudança Climática , Spheniscidae , Animais , Austrália , Umidade , Modelos Teóricos , Chuva , Temperatura
5.
R Soc Open Sci ; 11(8): 240593, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39205992

RESUMO

Despite increasing concern about the effects of anthropogenic noise on marine fauna, relevant research is limited, particularly in those inaccessible species, such as the Little Penguin (Eudyptula minor). In this study, we collected freshly deceased Little Penguins for dissection and micro-computed tomography (microCT) scans. The head structures, including the ear apparatus, were reconstructed based on high-resolution imaging data for the species. Moreover, three-dimensional finite-element models were built based on microCT data to simulate the sound reception processes and ear responses to the incident planar waves at the selected frequencies. The received sound pressure fields and motion (i.e. displacement and velocity) of the internal ear-related structures were modelled. The synergistic response of ear components to incident aerial and underwater sounds was computed to predict the hearing capabilities of the Little Penguins across a broad frequency range (100 Hz-10 kHz), both in air and under water. Our predicted data showed good agreement with other diving birds in both the form and range of auditory sensitivity. This study demonstrates a promising method to study hearing in other inaccessible animals. The outputs from this study can inform noise impact mitigation and conservation management.

6.
Biol Open ; 13(5)2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38639412

RESUMO

Penguins are proficient swimmers, and their survival depends on their ability to catch prey. The diving behaviour of these fascinating birds should then minimize the associated energy cost. For the first time, the energy cost of penguin dives is computed from the free-ranging dive data, on the basis of an existing biomechanical model. Time-resolved acceleration and depth data collected for 300 dives of little penguins (Eudyptula minor) are specifically employed to compute the bird dive angles and swimming speeds, which are needed for the energy estimate. We find that the numerically obtained energy cost by using the free-ranging dive data is not far from the minimum cost predicted by the model. The outcome, therefore, supports the physical soundness of the chosen model; however, it also suggests that, for closer agreement, one should consider previously neglected effects, such as those due to water currents and those associated with motion unsteadiness. Additionally, from the free-ranging dive data, we calculate hydrodynamic forces and non-dimensional indicators of propulsion performance - Strouhal and Reynolds numbers. The obtained values further confirm that little penguins employ efficient propulsion mechanisms, in agreement with previous investigations.


Assuntos
Mergulho , Spheniscidae , Natação , Animais , Spheniscidae/fisiologia , Fenômenos Biomecânicos , Mergulho/fisiologia , Natação/fisiologia , Locomoção/fisiologia , Metabolismo Energético
7.
Vision (Basel) ; 7(1)2023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36649051

RESUMO

Corneal confocal microscopy has not previously been performed in penguins, despite recognition of its unusually flat shape. To identify features that the penguin shares with other birds and or mammals and those specific to penguins, we undertook confocal microscopic examination of two little (Eudyptula minor), four gentoo (Pygoscelis papua) and five king (Aptenodytes patagonicus) penguin corneas. Transmission electron microscopy was performed on one gentoo and one king penguin, for finer details. Features shared with other higher vertebrates included a five-layered cornea and a similar limbus. Typically avian were a lower density of stromal cells, a more regular arrangement of collagen bands and an absent basal nerve plexus. Features unique to penguins included a flattened superficial epithelium (king penguin), stromal myofibroblasts (all) and an irregular endothelium (little penguin). Other features uniquely identified by confocal microscopy in birds include epithelial and stromal nerves, guttata and stromal imprints on Descemet's membrane. Transmission electron microscopy identified a lack of wing cells (king penguin), greater posterior collagen lamellae thickness (gentoo penguin) and significantly less interlacing of collagen lamellae in the central cornea (king and gentoo). Most of these unique features are yet to be explained, but some could be adaptations to diving.

8.
Int J Parasitol Parasites Wildl ; 17: 211-217, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35198375

RESUMO

Routine post mortems of deceased penguins from Penguin Island, Western Australia, found that a temporal cluster of cases presented with characteristic gross and microscopic changes, namely birds in good body condition with hepatomegaly and splenomegaly, multifocal hepatic and splenic necrosis and numerous, 1-2 µm diameter protozoan parasites within the necrotic foci. Electron microscopy identified the protozoa as belonging to the phylum Apicomplexa. Molecular investigations by PCR gave inconsistent results. PCR performed by an external laboratory identified a novel Haemoproteus spp. organism in samples from 4 of 10 cases from this group, while PCR at Murdoch University identified Toxoplasma gondii in 12 of 13 cases (including 9 of the 10 assayed at the external laboratory). Immunohistochemistry of formalin fixed tissues also identified Toxoplasma in the hepatic and splenic lesions. The distinctive mortalities which were observed in this group of penguins are attributed to a fulminant toxoplasmosis, with a concurrent Haemoproteus infection in some cases. Though the clinical signs of infection are unknown, the gross and microscopic appearance at post mortem is sufficiently characteristic to allow a diagnosis to be made on these features. Definitive confirmation of Toxoplasma infection can be made by immunohistochemistry or PCR.

9.
Vision Res ; 201: 108122, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36152389

RESUMO

Penguins (Spheniscidae) are a diverse clade of flightless, marine birds. Their eyes, likely a primary driver of behaviour, have been noted to have anatomic adaptations to their amphibious lifestyle. In particular, they have a relatively flat cornea, which would make the transition from a subaerial to a submarine environment require less accommodative effort. However, the ocular dimensions are not known for many penguin species, despite the diversity within the family, and their accommodative abilities have been the source of some dispute. In this study we undertook to establish the basic dimensions of the eye of the smallest, a mid-sized penguin and the second largest penguin. The power of the front surface of the cornea was inversely related to the size of both the eye and penguin, being 41.3 D in the little penguin (Eudyptula minor), a power greater than previously measured in any other penguin species, 26.3 D in the gentoo (Pygoscelis papua) and 19.1 D in the king penguin (Aptenodytes patagonicus). All other dimensions increased or decreased in line with the size of the eye. All penguins were able to achieve emmetropia in air. The gentoo appeared to be emmetropic underwater. A finding of central corneal thickening in some penguins may be artefactual. Calculations using the ocular dimensions demonstrated that the mean retinal illumination of an extended source of light in the little penguin eye is less than that of its larger, deeper-diving relatives.


Assuntos
Spheniscidae , Humanos , Animais , Acomodação Ocular , Córnea , Retina
10.
Ecol Evol ; 11(10): 5393-5401, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34026015

RESUMO

The extrinsic and intrinsic factors affecting differing reproductive strategies among populations are central to understanding population and evolutionary ecology. To evaluate whether individual reproductive strategies responded to annual patterns in marine productivity and age-related processes in a seabird we used a long term (2003-2013), a continuous dataset on nest occupancy and attendance at the colony by little penguins (Eudyptula minor) at Phillip Island (Victoria, Australia). We found that concurrent with a secondary annual peak of marine productivity, a secondary peak in colony attendance and nest occupancy was observed in Autumn (out of the regular breeding season in spring/summer) with individuals showing mating-like behavior. Individuals attending this autumn peak averaged 2.5 years older than those individuals that exclusively bred during spring/summer. Rather than being a naïve response by younger and inexperienced birds misreading environmental cues, our data indicate that the autumn peak attendance is an earlier attempt to breed by older and more experienced penguins. Therefore, we provide strong support for the fundamental prediction of the life-history theory of increasing investment in reproduction with age to maximize lifetime fitness as future survival prospects diminish and experience increases.

11.
Ecol Evol ; 10(13): 6610-6622, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32724536

RESUMO

Changes in marine ecosystems are easier to detect in upper-level predators, like seabirds, which integrate trophic interactions throughout the food web.Here, we examined whether diving parameters and complexity in the temporal organization of diving behavior of little penguins (Eudyptula minor) are influenced by sea surface temperature (SST), water stratification, and wind speed-three oceanographic features influencing prey abundance and distribution in the water column.Using fractal time series analysis, we found that foraging complexity, expressed as the degree of long-range correlations or memory in the dive series, was associated with SST and water stratification throughout the breeding season, but not with wind speed. Little penguins foraging in warmer/more-stratified waters exhibited greater determinism (memory) in foraging sequences, likely as a response to prey aggregations near the thermocline. They also showed higher foraging efficiency, performed more dives and dove to shallower depths than those foraging in colder/less-stratified waters.Reductions in the long-term memory of dive sequences, or in other words increases in behavioral stochasticity, may suggest different strategies concerning the exploration-exploitation trade-off under contrasting environmental conditions.

12.
Parasitol Int ; 66(6): 837-840, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28797592

RESUMO

Nematodes belonging to the genus Anisakis are important parasites due to their abundance in seafood and health impacts on humans. In the present study Anisakis larvae were found in a number of uncommon hosts including the Grey petrel, Procellaria cinerea, the Little penguin, Eudyptula minor, Blue-lipped sea krait, Laticauda laticaudata and Spinner shark, Carcharhinus brevipinna. Morphological examination showed nematodes in these animals are Anisakis larval type I. Genetic characterisation suggested that the larva from one Grey petrel was Anisakis berlandi, whereas the other larvae from the second Grey petrel and from the little penguin were Anisakis pegreffii. A number of larvae found in Blue-lipped sea krait and Spinner shark were identified as Anisakis typica. This is the first report of infective stage of Anisakis larvae parasitising hosts other than teleost fish. Understanding of the extent of infection and the pathogenicity of anisakid nematodes in hosts found in the present study is important in the conservation studies and management plans of these hosts.


Assuntos
Anisaquíase/veterinária , Anisakis/fisiologia , Doenças das Aves/parasitologia , Aves , Doenças dos Peixes/parasitologia , Tubarões , Serpentes , Animais , Anisaquíase/parasitologia , Anisakis/anatomia & histologia , Anisakis/genética , Anisakis/crescimento & desenvolvimento , Interações Hospedeiro-Parasita , Larva/anatomia & histologia , Larva/genética , Larva/crescimento & desenvolvimento , Larva/fisiologia , Nova Caledônia , Spheniscidae , Vitória
13.
Integr Med Res ; 6(2): 156-164, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28664139

RESUMO

BACKGROUND: Animation characters are created to embody distinctive personalities and body images; however, these features have not been analyzed with objective measures based on East Asian theory. The purpose of this study was to analyze the biopsychological features of seven animation characters in Pororo the Little Penguin, which scored unprecedented success in Korea, with clinically validated and standardized measures of Sasang typology. METHODS: Forty-one graduate students completed a survey examining body mass index (BMI) and Sasang Personality Questionnaire (SPQ) of seven characters in Pororo the Little Penguin after watching three selected episodes. The differences in physical appearance and psychological traits among animation characters were analyzed with analysis of variance. RESULTS: SPQ and BMI showed distinctive biopsychological features of seven animation characters. Pororo (28.29 ± 6.38 and 36.61 ± 3.09) was a typical So-Yang type boy, Petty (20.98 ± 4.07 and 31.66 ± 4.59) was a typical So-Yang type girl, and Loopy (28.05 ± 6.60 and 22.78 ± 4.78) was a typical So-Eum type girl in terms of BMI and SPQ, respectively. The BMI and SPQ of Poby (41.10 ± 4.26 and 22.32 ± 3.48) and Harry (19.63 ± 5.17 and 37.61 ± 2.40) showed the most obvious contrast. CONCLUSION: This study showed that SPQ and BMI are useful objective measures for analyzing the biopsychosocial features of animation characters as well as patients. The interdisciplinary research methodology of Sasang typology suggested here would provide useful tools for educating healthcare professionals and the general public about Korean medicine, and also contribute to the development of animation characters.

14.
J Biol Rhythms ; 31(2): 194-204, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26823445

RESUMO

Visible light on Earth largely comes from the sun, including light reflected from the moon. Predation risk is strongly determined by light conditions, and some animals are nocturnal to reduce predation. Artificial lights and its consequent light pollution may disrupt this natural behavior. Here, we used 13 years of attendance data to study the effects of sun, moon, and artificial light on the attendance pattern of a nocturnal seabird, the little penguin Eudyptula minor at Phillip Island, Australia. The little penguin is the smallest and the only penguin species whose activity on land is strictly nocturnal. Automated monitoring systems recorded individually marked penguins every time they arrived (after sunset) at or departed (before sunrise) from 2 colonies under different lighting conditions: natural night skylight and artificial lights (around 3 lux) used to enhance penguin viewing for ecotourism around sunset. Sunlight had a strong effect on attendance as penguins arrived on average around 81 min after sunset and departed around 92 min before sunrise. The effect of moonlight was also strong, varying according to moon phase. Fewer penguins came ashore during full moon nights. Moon phase effect was stronger on departure than arrival times. Thus, during nights between full moon and last quarter, arrival times (after sunset) were delayed, even though moonlight levels were low, while departure times (before sunrise) were earlier, coinciding with high moonlight levels. Cyclic patterns of moon effect were slightly out of phase but significantly between 2 colonies, which could be due to site-specific differences or presence/absence of artificial lights. Moonlight could be overridden by artificial light at our artificially lit colony, but the similar amplitude of attendance patterns between colonies suggests that artificial light did not mask the moonlight effect. Further research is indeed necessary to understand how seabirds respond to the increasing artificial night light levels.


Assuntos
Ritmo Circadiano/fisiologia , Luz , Atividade Motora , Spheniscidae/fisiologia , Animais , Cruzamento , Luz/efeitos adversos , Lua , Luz Solar
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