Publications

TitleAbstractYear
Filter
PMID
Filter
pasteurella multocida infections in rockhopper penguins (eudyptes chrysocome) from campbell island, new zealand.during an investigation into the population decline of rockhopper penguins (eudyptes chrysocome) on campbell island, new zealand, avian cholera (pasteurella multocida) was found in dead adults and chicks. an rna enveloped virus was isolated from ixodes uriae, a tick which commonly parasitizes rockhopper penguins on the island. it is not known whether this virus is virulent for penguins. no evidence was obtained to suggest that avian cholera was the principal cause for the decline in the rockhopp ...19902338734
chronic enteritis associated with edwardsiella tarda infection in rockhopper penguins. 19854077643
aspergillus spp. seropositivity in new zealand penguins.one hundred-fifty yellow-eyed penguins (megadyptes antipodes) of 8 populations, 20 little blue penguins (eudyptula minor) of 2 populations, 9 rockhopper penguins (eudyptes chrysocome), and 5 adelie penguins (pygoscelis adeliae) from new zealand (nz) and antarctica (latitude range; 39 degrees 30' s - 77 degrees 13' s) were tested by indirect enzyme-linked immunosorbent assays (elisa) for fungal aspergillus spp. igg. one hundred-ten of 184 (60%) penguins were seropositive, and seroprevalence was r ...19958587585
health evaluation of free-ranging rockhopper penguins (eudyptes chrysocomes) in argentina.as part of annual colony counts in santa cruz province, argentina, a health survey of rockhopper penguins (eudyptes chrysocomes) was conducted in 1994. forty-five birds were examined during handling procedures, and blood and fecal samples were collected for laboratory analysis. all birds appeared to be in good condition. no ecto- or endoparasites were found. hematology, plasma chemistry, and plasma mineral levels were measured and correlated with the results of bacterial and viral serology. anti ...199910367640
what ecological factors can affect albumen corticosterone levels in the clutches of seabirds? timing of breeding, disturbance and laying order in rockhopper penguins (eudyptes chrysocome chrysocome).female birds deposit corticosterone into their eggs. elevated concentrations of this hormone may interfere with the development of their offspring, and mothers should thus regulate corticosterone levels deposited into the eggs adaptively. however, if females are unable to regulate deposition, then the corticosterone concentration in eggs should reflect that in female plasma and should be influenced by stressors to the females. we measured corticosterone levels in the albumen of rockhopper pengui ...200919341737
differences in the stable isotope signatures of seabird egg membrane and albumen--implications for non-invasive studies.in many bird species, egg membranes can be obtained non-invasively after the chicks have hatched, and stable isotope analysis of egg membranes can be used to study the diet and foraging distribution of these birds during egg formation. it has been suggested that the enrichment factors of albumen and egg membranes differ for 13c, but are similar for 15n. in this study, we compared carbon and nitrogen stable isotopes of the membranes and albumen of individual eggs of three wild seabird species, th ...200919890954
discospondylitis caused by staphylococcus aureus in an african black-footed penguin (spheniscus demersus).a 22-year-old female african black-footed penguin (spheniscus demersus), housed indoors with other african and rockhopper penguins, was presented acutely with lethargy, ataxia, and hind limb weakness after a molt. the penguin would assume a hunched position and, when resting, sat on its hocks or lay on its keel. physical and neurologic examination revealed hind limb paraparesis, proprioceptive deficits, and tiptoe walking. results of a complete blood cell count and biochemical analysis revealed ...201223409435
evaluating the impact of handling and logger attachment on foraging parameters and physiology in southern rockhopper penguins.logger technology has revolutionised our knowledge of the behaviour and physiology of free-living animals but handling and logger attachments may have negative effects on the behaviour of the animals and their welfare. we studied southern rockhopper penguin (eudyptes chrysocome) females during the guard stage in three consecutive breeding seasons (2008/09-2010/11) to evaluate the effects of handling and logger attachment on foraging trip duration, dive behaviour and physiological parameters. sma ...201223185623
penguin chicks benefit from elevated yolk androgen levels under sibling competition.crested penguins (genus eudyptes) have a peculiar hatching pattern, with the first-laid egg (a-egg) hatching after the second-laid egg (b-egg) and chicks from a-eggs typically having a much lower survival probability. maternal yolk androgens have been suggested to contribute to the competitive superiority of the b-chick in southern rockhopper penguins eudyptes chrysocome, given their important role in mediating sibling competition in other species. we therefore increased the yolk androgen levels ...201222860073
penguins as bioindicators of mercury contamination in the southern ocean: birds from the kerguelen islands as a case study.seabirds have been used extensively as bioindicators of mercury (hg) contamination in the marine environment, although information on flightless species like penguins remains limited. in order to assess the use of penguins as bioindicators of hg contamination in subantarctic and antarctic marine ecosystems, hg concentrations were evaluated in the feathers of the four species that breed on the kerguelen islands in the southern indian ocean. compared to other seabirds, adult kerguelen penguins had ...201323542487
females paired with new and heavy mates reduce intra-clutch differences in resource allocation.reproductive investment affects both offspring and parental fitness and influences the evolution of life histories. females may vary their overall primary reproductive effort in relation to the phenotypic characteristics of their mate. however, the effects of male quality on differential resource allocation within clutches have been largely neglected despite the potential implications for mate choice and population dynamics, especially in species exhibiting biparental care and brood reduction. f ...201323967280
the complete sequence of the mitochondrial genome of the african penguin (spheniscus demersus).the complete mitochondrial genome of the african penguin (spheniscus demersus) was sequenced. the molecule was sequenced via next generation sequencing and primer walking. the size of the genome is 17,346 bp in length. comparison with the mitochondrial dna of two other penguin genomes that have so far been reported was conducted namely; little blue penguin (eudyptula minor) and the rockhopper penguin (eudyptes chrysocome). this analysis made it possible to identify common penguin mitochondrial d ...201424157264
good days, bad days: wind as a driver of foraging success in a flightless seabird, the southern rockhopper penguin.due to their restricted foraging range, flightless seabirds are ideal models to study the short-term variability in foraging success in response to environmentally driven food availability. wind can be a driver of upwelling and food abundance in marine ecosystems such as the southern ocean, where wind regime changes due to global warming may have important ecological consequences. southern rockhopper penguins (eudyptes chrysocome) have undergone a dramatic population decline in the past decades, ...201324236139
ocular findings and reference values for selected ophthalmic diagnostic tests in the macaroni penguin (eudyptes chrysolophus) and southern rockhopper penguin (eudyptes chrysocome).to describe ophthalmic examination findings and standard diagnostic test results in 2 penguin species.201524238103
malignant melanoma in the penguin: characterization of the clinical, histologic, and immunohistochemical features of malignant melanoma in 10 individuals from three species of penguin.malignant melanomas are aggressive neoplasms that are relatively common in penguins compared to other avian species. in this study, the clinical and pathologic characteristics of melanocytic neoplasms in five macaroni (eudyptes chrysolophus), three rock hopper (eudyptes chrysocome), and two humboldt (spheniscus humboldti) penguins are described. tumors most commonly occurred in the skin of the foot or hock, and were seen in the subcutaneous muscle, especially near the beak/oral cavity. gross les ...201425314820
love thy neighbour or opposites attract? patterns of spatial segregation and association among crested penguin populations during winter.competition for food among populations of closely related species and conspecifics that occur in both sympatry and parapatry can be reduced by interspecific and intraspecific spatial segregation. according to predictions of niche partitioning, segregation is expected to occur at habitat boundaries among congeners and within habitats among conspecifics, while negative relationships in the density of species or populations will occur in areas of overlap. we tested these predictions by modelling th ...201425505357
individual consistency and phenotypic plasticity in rockhopper penguins: female but not male body mass links environmental conditions to reproductive investment.in marine habitats, increasing ocean temperatures due to global climate change may distinctly reduce nutrient and consequently food availability for seabirds. food availability is a known driver of body mass and reproductive investment in birds, but these traits may also depend on individual effects. penguins show extreme intra-annual body mass variation and rely on accumulated body reserves for successful breeding. however, no study so far has tested individual consistency and phenotypic respon ...201526030824
mates but not sexes differ in migratory niche in a monogamous penguin species.strong pair bonds generally increase fitness in monogamous organisms, but may also underlie the risk of hampering it when re-pairing fails after the winter season. we investigated whether partners would either maintain contact or offset this risk by exploiting sex-specific favourable niches during winter in a migratory monogamous seabird, the southern rockhopper penguin eudyptes chrysocome. using light-based geolocation, we show that although the spatial distribution of both sexes largely overla ...201526562934
intraocular pressure in southern rockhopper (eudyptes chrysocome) and macaroni penguins (eudyptes chrysolophus): evaluation of influencing factors.ophthalmic examinations were performed on 160 macaroni penguins (eudyptes chrysolophus) and 90 southern rockhopper penguins (eudyptes chrysocome) at eight north american zoos and aquaria. intraocular pressure (iop) was measured using rebound tonometry while penguins were held in two different body positions. correlations between iop and factors including age, body position, eye pathology, and housing parameters were evaluated. normal macaroni penguins had a mean iop of 42.0 ± 9.7 mm hg. normal r ...201627010282
is individual consistency in body mass and reproductive decisions linked to individual specialization in foraging behavior in a long-lived seabird?individual specialization in diet or foraging behavior within apparently generalist populations has been described for many species, especially in polar and temperate marine environments, where resource distribution is relatively predictable. it is unclear, however, whether and how increased environmental variability - and thus reduced predictability of resources - due to global climate change will affect individual specialization. we determined the within- and among-individual components of the ...201627386091
evaluation of potential risk factors associated with cataract in captive macaroni (eudyptes chrysolophus) and rockhopper penguins (eudyptes chrysocome).complete ophthalmic examinations were performed on 160 macaroni penguins ( eudyptes chrysolophus ) and 90 rockhopper penguins ( eudyptes chrysocome ) at eight north american zoological institutions. cataract prevalence in the macaroni population was 46.5% (n = 74) of penguins and 42.3% (135/319) of eyes. cataract prevalence in the rockhopper population was 45.5% (n = 40) of penguins and 40.6% (73/180) of eyes. the mean age of macaroni penguins without ocular disease was 7.4 ± 5.8 yr, while that ...201627691963
cosmocephalus obvelatus (creplin, 1825) (nematoda: acuariidae) collected from the esophagus of rockhopper penguin, eudyptes crestatus. 19883373929
extreme intra-clutch egg size dimorphism is not coupled with corresponding differences in antioxidant capacity and stable isotopes between eggs.oviparous females need to allocate resources optimally to their eggs in order to maximize their fitness. among these resources, dietary antioxidants, acquired by females and transferred to the eggs during egg formation, can greatly affect the development and survival of the embryo and chick. in crested penguins, incubation starts after the second and last egg is laid and, as opposed to many other bird species, this egg hatches first, thereby enhancing the survival of the chick. here, we assessed ...201728062221
organohalogenated contaminants in plasma and eggs of rockhopper penguins: does vitellogenin affect maternal transfer?although many studies have investigated organohalogenated contaminants (ohcs) in yolk, little is known about the mechanisms and timing of transfer of ohcs from the female to the egg. vitellogenin, a yolk precursor, has been suggested to play a role in this transport. we here report for the first time the temporal changes in ohc and an index of vitellogenin concentrations in female plasma from the pre-laying period to clutch completion in free-living birds: the southern rockhopper penguin (eudypt ...201728392239
high-throughput gender identification of penguin species using melting curve analysis.most species of penguins are sexual monomorphic and therefore it is difficult to visually identify their genders for monitoring population stability in terms of sex ratio analysis. in this study, we evaluated the suitability using melting curve analysis (mca) for high-throughput gender identification of penguins. preliminary test indicated that the griffiths's p2/p8 primers were not suitable for mca analysis. based on sequence alignment of chromo-helicase-dna binding protein (chd)-w and chd-z ge ...201424555797
basal metabolic rate of the black-faced sheathbill (chionis minor): intraspecific variation in a phylogenetically distinct island endemic.metabolic rate is a fundamental characteristic of all organisms. it covaries most significantly with activity, body mass, seasonality, and temperature. nonetheless, substantial additional variation in metabolic rate, especially either resting rate or basal rate, is associated with a range of factors including phylogenetic position, ecological distinctiveness, range position, and diet. understanding this variation is a key goal of physiological ecology. the black-faced sheathbill is a phylogeneti ...201727082724
an evaluation of infrared thermography for detection of bumblefoot (pododermatitis) in penguins.the objective of this study was to evaluate infrared thermography as a noninvasive screening tool for detection of pododermatitis during the developing and active stages of disease in three species of penguins: king penguin (aptenodytes patagonicus) , macaroni penguin (eudyptes chrysolophus), and rockhopper penguin (eudyptes chrysocome). in total, 67 penguins were examined every 3 mo over a 15-mo period. at each exam, bumblefoot lesions were characterized and measured, and a timed series of ther ...201627468019
maternal deposition of yolk corticosterone in clutches of southern rockhopper penguins (eudyptes chrysocome chrysocome).high corticosterone levels can have deleterious effects in developing avian embryos and chicks. therefore, it may be adaptive for avian mothers to reduce corticosterone transfer to their eggs. however, until now, data about the active or/and passive role of mothers in corticosterone transfer to eggs are inconclusive. here, we study maternal investment into a- and b-eggs of southern rockhopper penguins (eudyptes chrysocome chrysocome). this species exhibits reversed hatching asynchrony and provid ...200919232349
the primary structure of the hemoglobin of the rock-hopper penguin (eudyptes crestatus, sphenisciformes).the blood of the rock-hopper penguin contains only one hemoglobin component, corresponding to the hb a of other birds. the primary structures of the alpha- and beta-chains are presented. the chains were separated by high-performance liquid chromatography and cleaved either enzymatically (alpha) or both enzymatically and chemically (beta). both the native chains and their peptides were sequenced using liquid and gas phase sequenators. the peptides were aligned using their homology to the sequence ...19883202958
migratory constraints on yolk precursors limit yolk androgen deposition and underlie a brood reduction strategy in rockhopper penguins.hormonally mediated maternal effects link maternal phenotype and environmental conditions to offspring phenotype. the production of lipid-rich maternal yolk precursors may provide a mechanism by which lipophilic steroid hormones can be transported to developing yolks, thus predicting a positive correlation between yolk precursors in mothers and androgen levels in eggs. using rockhopper penguins (eudyptes chrysocome), which produce a two-egg clutch characterized by extreme egg-size dimorphism, re ...201222809718
intra-clutch ratio of yolk progesterone level changes with laying date in rockhopper penguins: a strategy to influence brood reduction?hatching asynchrony in avian species generally leads to a size hierarchy among siblings, favouring the first-hatched chicks. maternally deposited hormones affect the embryo and chick's physiology and behaviour. it has been observed that progesterone, a hormone present at higher levels than other steroid hormones in egg yolks, is negatively related to body mass in embryos, chicks and adults. a differential within-clutch progesterone deposition could therefore be linked to the size hierarchy betwe ...201122110758
measuring corticosterone in seabird egg yolk and the presence of high yolk gestagen concentrations.large inter-species differences have been found in yolk corticosterone amounts in avian eggs. while some studies have failed to detect significant amounts of corticosterone, in other species high amounts have been recorded, such as in a recent study of southern rockhopper penguins eudyptes chrysocome chrysocome. however, attention has been drawn recently to the fact that many antibodies for corticosterone measurement cross-react with other steroids present in the yolk. in particular, progesteron ...201121640119
semen characteristics and artificial insemination in rockhopper penguins (eudyptes chrysocome chrysocome).this work was performed as part of a multi-year study to determine the cause of the low fertility in captive rockhopper penguins (eudyptes chrysocome chrysocome) and attempt to increase the fertility through artificial insemination (ai). semen collection and characterization was performed on 14 male rockhopper penguins. the samples were evaluated for volume, sperm concentration, and sperm quality (motility, forward motility, viability, and morphology). there was a large variation between individ ...201221538504
organohalogenated contaminants in eggs of rockhopper penguins (eudyptes chrysocome) and imperial shags (phalacrocorax atriceps) from the falkland islands.in this study, we evaluated the use of seabird eggs of two common bird species from the falkland islands as bioindicators of contamination with organohalogenated contaminants (ohcs). we compared contamination levels and profiles of different ohcs between eggs of the rockhopper penguin (eudyptes chrysocome) and the imperial shag (phalacrocorax atriceps). in addition, laying order effects on ohc concentrations and profiles were also investigated in both species. for polychlorinated biphenyls (pcbs ...201121529893
yolk androgen deposition without an energetic cost for female rockhopper penguins: a compensatory strategy to accelerate brood reduction?whether androgen deposition in eggs is physiologically costly for female birds has remained a crucial but unsolved question, despite a broad use of this assumption in functional studies. we tested whether females depositing high androgen concentrations experienced higher mass losses than females depositing low androgen concentrations. analysing female body mass change during egg formation in rockhopper penguins (eudyptes chrysocome chrysocome), we observed no energetic cost to androgen depositio ...201121325311
yolk androgen deposition in rockhopper penguins, a species with reversed hatching asynchrony.to maximize fitness, females should invest optimally in the siblings within a litter or brood and adapt this investment to environmental conditions. chick mass and yolk androgens have been shown to influence the outcome of sibling competition. in birds, asynchronous hatching plays a major role in this process and often leads to brood reduction. we studied maternal deposition of yolk androgens in eggs of southern rockhopper penguins (eudyptes chrysocome chrysocome). contrary to other avian models ...201121130090
reversed hatching order, body condition and corticosterone levels in chicks of southern rockhopper penguins (eudyptes chrysocome chrysocome).in altricial and semi-altricial species, asynchronous hatching gives the first chicks to hatch an initial advantage over other siblings and often leads to the elimination of the smallest chicks. both baseline corticosterone and acute stress-induced corticosterone levels have been shown to be higher in food deprived chicks than in chicks fed ad libitum. however, first-hatched chicks have also been shown to exhibit higher corticosterone levels than last-hatched chicks, suggesting an influence of t ...201020850443
leucocyte profiles and corticosterone in chicks of southern rockhopper penguins.the immune system is essential for health and survival of vertebrates, yet still little is known about the ontogeny of the immune system in wild birds. the southern rockhopper penguin (eudyptes chrysocome chrysocome) is a semi-altricial seabird with a long developmental period and reversed hatching asynchrony, favouring the survival of b-chicks. we compared leucocyte counts and baseline corticosterone levels of southern rockhopper penguin chicks under different preconditions such as sex and orig ...201120721561
semen collection and characterization in rockhopper penguins (eudyptes chrysocome chrysocome).low egg fertility and hatchability is a common problem in captive populations of rockhopper penguins (eudyptes chrysocome chrysocome). these conditions make sustaining a captive population challenging. a method for collecting and evaluating semen from rockhopper penguins was developed to assist in the evaluation of low egg fertility found in one captive population. six adult male rockhopper penguins were conditioned to allow semen collection once a week from the start of breeding season until ej ...200717469270
genetic isolation and divergence in sexual traits: evidence for the northern rockhopper penguin eudyptes moseleyi being a sibling species.the taxonomic status of populations of rockhopper penguins (eudyptes chrysocome) is still enigmatic. northern populations differ from southern ones in breeding phenology, song characteristics and head ornaments used as mating signals. we conducted a molecular analysis using mitochondrial dna sequencing to test if there is a gene flow barrier between northern (subtropical) populations and southern (subantarctic) populations in relation to the subtropical convergence, a major ecological boundary f ...200616968279
health evaluation of penguins (sphenisciformes) following mortality in the falklands (south atlantic).in the falklands, heavy mortality of rock-hopper penguins eudyptes chrysocome occurred during the 1985-86 breeding season. starvation was diagnosed as the primary cause of death, possibly caused by a shortage of euphausiid crustaceans (krill) due to unusual meterological conditions. 'puffinosis' may possibly have been a contributory factor; otherwise no conclusive evidence of infectious disease or toxicosis was found and also no evidence of radioactive contamination. in the 1986-87 breeding seas ...200111558725
coexistence of oceanic predators on wintering areas explained by population-scale foraging segregation in space or time.ecological niche theory predicts segregation mechanisms that mitigate potential competition between closely related organisms. however, little is known outside the breeding season, when central-place foraging animals may move on larger scales. this study tested for segregation mechanisms within the same 2007 inter-breeding period on three neighboring populations of avian predators from the southern indian ocean: eastern rockhopper penguins eudyptes filholi from crozet and kerguelen and northern ...201222486093
isotopic discrimination between food and blood and feathers of captive penguins: implications for dietary studies in the wild.using measurements of naturally occurring stable isotopes to reconstruct diets or source of feeding requires quantifying isotopic discrimination factors or the relationships between isotope ratios in food and in consumer tissues. diet-tissue discrimination factors of carbon ((13)c/(12)c, or delta (13)c) and nitrogen ((15)n/(14)n, or delta (15)n) isotopes in whole blood and feathers, representing noninvasive sampling techniques, were examined using three species of captive penguins (king aptenody ...201515702469
sex identification of four penguin species using locus-specific pcr.traditional methods for sex identification are not applicable to sexually monomorphic species, leading to difficulties in the management of their breeding programs. to identify sex in sexually monomorphic birds, molecular methods have been established. two established primer pairs (2550f/2718r and p8/p2) amplify the chd1 gene region from both the z and w chromosomes. here, we evaluated the use of these primers for sex identification in four sexually monomorphic penguin species: king penguins (ap ...201322383375
blood oxygen- and carbon dioxide-carrying properties in captive penguins: effects of moulting and inter-specific comparison.venous blood gas-carrying properties were compared in the three captive species of penguins (king, gentoo and rockhopper) at océanopolis (france). captivity permitted to control environmental influences. given their different ecology and diving behaviour in the wild, it was wondered whether milder conditions and dive privation have repercussions on parameters determining oxygen storage and acid-base status of these birds. in addition, this work provided the opportunity to study the effects of mo ...201424231467
vision of the humboldt penguin (spheniscus humboldti) in air and water.refractive states measured by retinoscopy and photorefraction indicate that the eyes of the humboldt penguin, spheniscus humboldti, are approximately emmetropic in air and water. extensive myopia in air, as predicted by earlier authors and by a recent anatomical study, is non-existent. photorefractive measurements of the refractive state, in water, of the humboldt penguin indicate that it can accommodate sufficiently to make up the loss of the refractive power of the cornea. the cornea of the hu ...20102881308
evidence for a new avian paramyxovirus serotype 10 detected in rockhopper penguins from the falkland islands.the biological, serological, and genomic characterization of a paramyxovirus recently isolated from rockhopper penguins (eudyptes chrysocome) suggested that this virus represented a new avian paramyxovirus (apmv) group, apmv10. this penguin virus resembled other apmvs by electron microscopy; however, its viral hemagglutination (ha) activity was not inhibited by antisera against any of the nine defined apmv serotypes. in addition, antiserum generated against this penguin virus did not inhibit the ...201020702635
haematology of wild penguins (spenisciformes) in the falkland islands.haematological values were determined in 50 rockhopper (eudyptes crestatus), 19 gentoo (pygoscelis papua) and 12 magellanic (spheniscus magellanicus) penguins from various sites on the falkland islands. adult magellanic penguins had significantly lower haemoglobin (hb) levels, packed cell volumes (pcv) and red cell counts (rbc) than adults of the other two species. hb, pcv and rbc values were also lower in juvenile birds than in adults and lower in post-moult than in pre-moult adults. comparison ...198918679879
plasma alpha-tocopherol, total lipids and total cholesterol in wild rockhopper, magellanic and gentoo penguins before and after moulting.post moult rockhopper penguins (eudyptes crestatus) had significantly higher plasma alpha-tocopherol (vitamin e), total lipid and total cholesterol concentrations than their pre-moult counterparts. in the magellanic penguins (spheniscus magellanicus) there were post moult increases in total lipid, cholesterol and alpha-tocopherol concentrations, but only the increase in alpha-tocopherol was significant. plasma alpha-tocopherol, total lipid and total cholesterol concentrations in post moult gento ...19892773196
mycobacterial airsacculitis caused by mycobacterium fortuitum in a southern rockhopper penguin (eudyptes chrysocome).a 21-year-old male southern rockhopper penguin (eudyptes chrysocome) was presented with a chronic history of intermittently decreased appetite, lethargy, and regurgitation. on the external physical examination, the bird was determined to be in fair-to-thin body condition with the complete blood count and plasma chemistry panel being largely unremarkable. full-body radiographic images were considered normal, and gastroscopy showed only mild gastritis and duodenitis. the penguin was euthanatized s ...202033099984
compound-specific stable isotope analyses in falkland islands seabirds reveal seasonal changes in trophic positions.while nitrogen and carbon stable isotope values can reflect ecological segregation, prey choice and spatial distribution in seabirds, the interpretation of bulk stable isotope values is frequently hampered by a lack of isotopic baseline data. in this study, we used compound-specific isotope analyses of amino acids (csia-aa) to overcome this constraint and to study interspecific differences, seasonal and historical changes in trophic positions of five seabird species, three penguins and two petre ...202032293412
metapopulation dynamics and foraging plasticity in a highly vagile seabird, the southern rockhopper penguin.population connectivity is driven by individual dispersal potential and modulated by natal philopatry. in seabirds, high vagility facilitates dispersal yet philopatry is also common, with foraging area overlap often correlated with population connectivity. we assess the interplay between these processes by studying past and current connectivity and foraging niche overlap among southern rockhopper penguin colonies of the coast of southern south america using genomic and stable isotope analyses. w ...202032273992
phylogeography, population structure, and species delimitation in rockhopper penguins (eudyptes chrysocome and eudyptes moseleyi).rockhopper penguins are delimited as 2 species, the northern rockhopper (eudyptes moseleyi) and the southern rockhopper (eudyptes chrysocome), with the latter comprising 2 subspecies, the western rockhopper (eudyptes chrysocome chrysocome) and the eastern rockhopper (eudyptes chrysocome filholi). we conducted a phylogeographic study using multilocus data from 114 individuals sampled across 12 colonies from the entire range of the northern/southern rockhopper complex to assess potential populatio ...201931737899
diet-tissue discrimination factors (δ15 n and δ13 c values) for blood components in magellanic (spheniscus magellanicus) and southern rockhopper (eudyptes chrysocome) penguins.analysis of the stable isotope ratios of carbon and nitrogen (δ13 c and δ15 n values) is increasingly being used to gain insight into predator trophic ecology, which requires accurate diet-tissue discrimination factors (dtdfs), or the isotopic difference between prey and predator. accurate dtdfs must be calculated from predators consuming an isotopically constant diet over time in controlled feeding experiments, but these studies have received little attention to date, especially among seabird s ...202031657501
fatal sarcocystis falcatula infection in three penguins.sarcocystis falcatula is a well-known cause of fatal pneumonia in some birds, particularly old world psittacines. here we describe fatal sarcosystosis due to s. falcatula in 3 penguins (family spheniscidae) under managed care, including one african penguin (spheniscus demersus), and two southern rockhopper penguins (eudyptes chrysocome). randomly distributed foci of necrosis, inflammatory cell infiltrates, edema, and variable numbers of round to elongated protozoal schizonts were observed in sec ...201931649941
training penguins to interact with enrichment devices for lasting effects.the modern zoo has brought about two major advances in the behavioral welfare of their exhibited animals: (a) the use of environmental enrichment to promote naturalistic behaviors and (b) the use of training to improve voluntary husbandry care. whereas training itself has been talked about as an effective enrichment strategy, little has been done to combine training procedures with enrichment. typically, enrichment is treated as a trial and error process, where potential enrichment items or proc ...201931355481
temporal and interspecific variation in feather mercury in four penguin species from macquarie island, australia.we measured mercury (hg) concentrations in feathers from four penguin species collected on macquarie island, southern ocean, to 1) establish baseline hg concentrations; and 2) compare hg from samples collected in 2002 ("modern") and from museum specimens collected between 1937 and 1976 ("historic"). inter-specific differences in feather hg reflected known differences in habitats and diversity of diets: benthic-foraging gentoo penguins and rockhopper penguins that foraged both inshore and offshor ...201931232305
suspected hypovitaminosis a-associated salt gland adenitis in northern rockhopper penguins ( eudyptes moseleyi).supraorbital salt-excreting glands are present in at least 10 avian orders and are largest in marine species, including penguins. diseases of the avian salt gland have been described infrequently. from september 2015, five captive northern rockhopper penguins ( eudyptes moseleyi) were presented over a 6-wk period for unilateral or bilateral supraorbital swellings. in september 2016, two cases recurred and two additional cases were identified. histopathology demonstrated salt gland adenitis with ...201829900787
avian cholera outbreaks threaten seabird species on amsterdam island.infectious diseases may be particularly critical for the conservation of endangered species. a striking example is the recurrent outbreaks that have been occurring in seabirds on amsterdam island for the past 30 years, threatening populations of three endangered seabird species and of the endemic, critically endangered amsterdam albatross diomedea amsterdamensis. the bacteria pasteurella multocida (avian cholera causative agent), and to a lesser extent erysipelothrix rhusiopathiae (erysipelas ca ...201829847561
sexual and individual foraging segregation in gentoo penguins pygoscelis papua from the southern ocean during an abnormal winter.knowledge about sexual segregation and gender-specific, or indeed individual specialization, in marine organisms has improved considerably in the past decade. in this context, we tested the "intersexual competition hypothesis" for penguins by investigating the feeding ecology of gentoo penguins during their austral winter non-breeding season. we considered this during unusual environmental conditions (i.e. the year 2009 had observations of high sea surface and air temperatures) in comparison wit ...201728362847
stable isotopes document seasonal changes in trophic niches and winter foraging individual specialization in diving predators from the southern ocean.1. climatic variation outside the breeding season affects fluctuations in population numbers of seabirds and marine mammals. a challenge in identifying the underlying biological mechanisms is the lack of information on their foraging strategies during winter, when individuals migrate far from their breeding grounds. 2. we investigated the temporal variability in resource partitioning within the guild of five sympatric subantarctic penguins and fur seals from crozet islands. the stable isotopic r ...200717584388
contrasting phylogeographic pattern among eudyptes penguins around the southern ocean.since at least the middle-miocene, the antarctic polar front (apf) and the subtropical front (stf) appear to have been the main drivers of diversification of marine biota in the southern ocean. however, highly migratory marine birds and mammals challenge this paradigm and the importance of oceanographic barriers. eudyptes penguins range from the antarctic peninsula to subantarctic islands and some of the southernmost subtropical islands. because of recent diversification, the number of species r ...201830504851
case studies of the impacts of cataract surgery on crested penguin welfare.as nonhuman animals age, geriatric individuals require additional care and veterinary support to ensure their well being. the focus on lifelong care is a relatively newer approach when providing good welfare, and few studies have examined how veterinary care impacts behavior at different ages or how best to accommodate geriatric individuals in zoos. the objectives of this study were to (a) assess both the immediate and long-term (one year later) behavioral impacts of cataract removal for macaron ...202030295508
penguin vision in air and water.refractive states measured by retinoscopy and photorefraction indicate that rockhopper (eudyptes crestatus), magellanic (spheniscus magellanicus) and gentoo (pygoscelis papua) penguins are approximately emmetropic in air and water. extensive myopia in air, as predicted by early authors, is nonexistent. photorefractive measurements of refractive state in water indicate that rockhopper, gentoo, magellanic and king (aptenodytes patagonica) penguins can accommodate sufficiently to make up for the lo ...19846534014
sperm structure and sperm motility of the african and rockhopper penguins with special reference to multiple axonemes of the flagellum.this study evaluated the semen of two penguin species from separate genera with reference to unique features in sperm structure using light microscopy and transmission electron microscopy. ejaculates from african penguin (n = 51) and rockhopper penguin (n = 9) contained on average more than 60% motile spermatozoa and a sperm concentration of 3274 × 10(6)/ml and 1423 × 10(6)/ml, respectively. the percentage progressive motility was similar for the two species as well as all the kinematics paramet ...201728708488
complete genome sequences of four avian paramyxoviruses of serotype 10 isolated from rockhopper penguins on the falkland islands.the first complete genome sequences of four avian paramyxovirus serotype 10 (apmv-10) isolates are described here. the viruses were isolated from rockhopper penguins on the falkland islands, sampled in 2007. all four genomes are 15,456 nucleotides in length, and phylogenetic analyses show them to be closely related.201728572332
deaths in rockhopper penguins. 200919168885
new candidate species most closely related to penguins.the phylogenetic position of the order spenisciformes in aves remains unclear despite several independent analyses based on morphological and molecular data. to address this issue, we determined the complete mtdna sequence of rockhopper penguins. the mitochondrial genome, excluding the region from the d-loop to 12srrna, was also sequenced for petrel, albatross, frigatebird, loon and grebe, which previous studies suggest are related to penguins. a maximum likelihood analysis of the phylogenetic p ...200616806742
body feather mercury and arsenic concentrations in five species of seabirds from the falkland islands.several pollutants, including heavy metals, magnify along the food chain, and top predators such as seabirds can be used to monitor their trends in the marine environment. we studied mercury and arsenic contamination in body feathers in penguins, petrels and cormorants in three islands of the falklands islands. there were significant differences among species and sites in the concentration of trace elements in feathers. black-browed albatrosses and gentoo penguins had consistently high mercury c ...201931546110
Displaying items 1 - 69 of 69