María José Palacios

Health of Antarctic birds: a review of their parasites, pathogens and diseases

Antarctic birds are not beyond the effects of parasites or pathogens. However, potential ecological consequences of wide-spread infections for bird populations in Antarctica have received little attention. In this paper, we review the information published about disease and parasites, and their effects on Antarctic birds. The information on host species, parasites and pathogens, and geographic regions is incomplete and data on ecological effects on the populations, including how birds respond to pathogens and parasites, are almost inexistent. We conclude that more research is needed to establish general patterns of spatial and temporal variation in pathogens and parasites, and to determine how such patterns could influence hosts. This information is crucial to limit the spread of outbreaks and may aid in the decision-making process should they occur.

Concentration of trace elements in feathers of three Antarctic penguins: Geographical and interspecific differences

Antarctica is often considered as one of the last pristine regions, but it could be affected by pollution at global and local scale. Concentrations of Al, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Cd and Pb were determinated by ICP-MS in feathers (n = 207 individuals) of gentoo, chinstrap and Adélie penguin collected in 8 locations throughout the Antarctic Peninsula (2006-2007). The highest levels of several elements were found in samples from King George Island (8.08, 20.29 and 1.76 μg g(-1) dw for Cr, Cu and Pb, respectively) and Deception Island (203.13, 3.26 and 164.26 μg g(-1) dw for Al, Mn and Fe, respectively), where probably human activities and large-scale transport of pollutants contribute to increase metal levels. Concentrations of Cr, Mn, Cu, Se or Pb, which are similar to others found in different regions of the world, show that some areas in Antarctica are not utterly pristine.

Gastrointestinal parasites in Chinstrap Penguins from Deception Island, South Shetlands, Antarctica

Knowledge about parasites of Antarctic birds is fragmented and scarce. The aim of this work is to contribute to the knowledge of gastrointestinal parasites of the Chinstrap Penguin (Pygoscelis antarctica) from Deception Island (South Shetlands, Antarctica). Gastrointestinal tracts of 64 fresh dead individuals (61 chicks and three adults) were collected from December 2006 to February 2009 and examined for macroparasites. Three adult parasite species were found: two Cestoda species (Parorchites zederi and Tetrabothrius pauliani) and one Nematoda species (Stegophorus macronectes). Also, immature acanthocephalans (Corynosoma sp.) were found in one penguin. The low parasite richness observed could be related to the stenophagic and pelagic diet of the host species. False negatives were found in coprological studies.

Seabird ticks (Ixodes uriae) distribution along the Antarctic Peninsula

The distribution of the tick Ixodes uriae is studied in the South Shetlands and different locations along the Antarctic Peninsula. Ticks were found beneath stones close to penguin rookeries of chinstrap, gentoo and adelie penguin, although no individuals were found parasitized. Our results showed that ticks are not distributed evenly along the Antarctic Peninsula being more common and abundant in the northern part with relative abundances of ticks ranging from 1 to 57 individuals per stone and from 2 to 26% of the stone inspected. Ticks are probably absent in the south.

Beak colouration as a possible sexual ornament in gentoo penguins: sexual dichromatism and relationship to body condition

Gentoo penguins (Pygoscelis papua) have conspicuous red beak spots, the function of which is currently unknown. We hypothesized that beak spots might be sexual ornaments and investigated sexual dichromatism, assortative mating and the possible relationship between beak spot colouration and body condition. Beak colouration was measured with a portable spectroradiometer in 19 breeding pairs of gentoo penguin. Body mass and body mass relative to structural body size were used as estimates of body condition. We found that beak spots were sexually dichromatic, as they were more UV in males and more violet in females, but males and females did not mate assortatively in relation to beak spot colouration. Body condition was strongly related to red colouration in males, with individuals in good condition having redder beaks and individuals in poor condition more orange beaks. The beaks of males in good condition were also brighter. Body condition was not significantly related to beak spot colouration in females, so females might show red beak spots because of genetic correlation with the male trait. These results suggest that the red colour of the beak spot has the potential to be a secondary sexual character in males. Interpretation of the sexual dichromatism in the UV colour will require further knowledge of the capability of gentoo penguins to discriminate small differences in UV wavelengths. In any case, experimental manipulation of beak colouration will be needed to ascertain the role of this trait.

Morphological, molecular and phylogenetic analyses of the spirurid nematode Stegophorus macronectes (Johnston & Mawson, 1942).

Stegophorus macronectes (Johnston & Mawson, 1942) is a gastrointestinal parasite found in Antarctic seabirds. The original description of the species, which was based only on females, is poor and fragmented with some unclear diagnostic characters. This study provides new morphometric and molecular data on this previously poorly described parasite. Nuclear rDNA sequences (18S, 5.8S, 28S and internal transcribed spacer (ITS) regions) were isolated from S. macronectes specimens collected from the chinstrap penguin Pygoscelis antarctica Forster on Deception Island, Antarctica. Using 18S rDNA sequences, phylogenetic analyses (maximum likelihood, maximum parsimony and Bayesian inference) of the order Spirurida were performed to determine the phylogenetic location of this species. Primer pairs of the ITS regions were designed for genus-level identification of specimens, regardless of their cycle, as an alternative to coprological methods. The utility of this molecular method for identification of morphologically altered specimens is also discussed.

Erythrocytic abnormalities in three Antarctic penguin species along the Antarctic Peninsula: biomonitoring of genomic damage

Pollutants and toxic contaminants produced in all parts of the world are transported to remote regions including Antarctica. Tourism, research, and fishing activities on this continent are another source of contamination. Toxic substances affect Antarctic species, and some produced genomic damage to the fauna. The genetic damage can be detected by microscopic observation of erythrocytic nuclear abnormalities (ENAs). We counted the number of ENAs in seven populations of three Pygoscelid penguin species, Adélie (Pygoscelis adeliae), Chinstrap (Pygoscelis antarctica), and Gentoo (Pygoscelis papua), and found important differences among species exposed to the same conditions. ENAs were more frequent in Adélie penguins than in the other two species. Inter-population comparisons within species showed remarkable differences in Adélie and Chinstrap penguins but not in Gentoo penguin. Frequency of ENAs in Adélie penguins was the highest in Yalour Island population, intermediate in King George Island population, and the lowest in Torgersen Island and Avian Island populations. In Chinstrap penguins, the highest number of ENAs was found on Deception Island, and significant differences were found only between Deception Island and King George Island populations. This information will provide baseline data to be used for assessing the evolution of genomic damage of penguins along the Antarctic Peninsula in the future.

Cellular and humoral immunity in two highly demanding energetic life stages: reproduction and moulting in the Chinstrap Penguin

AbstractReproduction and moulting are costly events in birds. Some studies have pointed out the possibility that the immune response is optimized and traded off against such costly functions. Moreover, it is also known that stressful conditions may lead to the suppression of immune functions. As reproduction and moulting do not overlap in penguins, they offer a good opportunity to explore the relationships between immunity and both events. Our aim is to compare physiological stress and immunity between breeding and moulting in the Chinstrap Penguin. Considering the large amount of energy expended during breeding and the almost total inactivity during moulting and the immunosuppression caused by stress, it is expected that the Chinstrap Penguin shows a higher degree of stress during breeding and that immunological capacity was lower in this life stage. As a measure of stress, we examined the heterophil/lymphocyte ratio. To account for an overall measure of the immunological status, we measured cellular immunity (total leukocyte count and the response to phytohaemagglutinin) and humoral immunity (immunoglobulin levels). All measures were taken in both breeding and moulting penguins. Our results showed that breeding was more stressful than moulting in the Chinstrap Penguin. Immunological differences between the two physiological activities showed a complex picture as cellular immunity values were higher during moulting and humoral immunity values were higher during breeding. Differences were also found between sexes with males showing higher levels of stress than females and lower values of total leukocyte count.ZusammenfassungZelluläre und humorale Immunität in zwei aus energetischer Sicht besonders herausfordernden Lebensphasen beim Kehlstreifenpinguin: Fortpflanzung und Mauser Aus energetischer Sicht sind Brutzeit und Mauser für Vögel sehr aufwändige Zeiten. Es gibt Studien, die zeigen, dass möglicherweise die Immunantwort optimiert und gegen derart teure „physiologische Funktionen“abgewogen wird. Überdies ist bekannt, dass stressige Lebensbedingungen zu einer Unterdrückung immunbiologischer Funktionen führen können. Da Fortpflanzung und Mauser bei Pinguinen zeitlich nicht überlappen, bietet sich hier eine gute Gelegenheit, mögliche Zusammenhänge zwischen diesen beiden Phasen und dem Immunsystem zu untersuchen. Dafür haben wir bei dieser Pinguinart während Mauser und Brutzeit physiologische Stressfaktoren und Funktionen des Immunsystems miteinander verglichen. Berücksichtigt man die hohen Energiekosten während der Brutzeit und die beinahe völlige Inaktivität während der Mauser sowie die Unterdrückung der Immunantwort durch Stress, wäre zu erwarten, dass Kehlstreifenpinguine (Pygoscelis antarcticus) während der Brutzeit ein höheres Stress-Level zeigen und ihre immunbiologische Kapazität in dieser Lebensphase geringer ist. Wir verwendeten das Verhältnis von heterophilen Antikörpern zu Lymphozyten als Maß für Stress. Für die Beurteilung des gesamt-immunologischen Zustands der Tiere benutzten wir Messungen der zellulären Immunität (gesamte Leukozyten-Anzahl und deren Reaktion auf Phytohämagglutinin) und der humoralen Immunantwort (Immunoglobulin-Level). Alle Messungen wurden sowohl bei brütenden als auch bei Pinguinen in der Mauser erhoben. Unsere Ergebnisse zeigten, dass für Kehlstreifenpinguine die Brutzeit stressiger als die Mauser war. Die immunologischen Unterschiede zwischen den beiden physiologischen Phasen ergaben ein recht komplexes Bild, weil die zellulären Immunologie-Werte während der Mauser höher waren, die humoralen Werte jedoch während der Brutzeit. Ferner wurden auch Unterschiede zwischen den beiden Geschlechtern festgestellt: die Männchen zeigten höhere Stresslevel als die Weibchen und niedrigere Leukozyten-Werte.