Nest-type associated microclimatic conditions as potential drivers of ectoparasite infestations in African penguin nests.

Nest design and characteristics can influence the microclimatic conditions in the nest. Nest-dwelling ectoparasites are sensitive to temperature and moisture and as such the conditions in the nest can influence parasite infestations. The endangered African penguin (Spheniscus demersus) breeds in different nest types and as yet little is known with regard to the microclimate and parasite infestation within these nests. This study characterized the microclimatic conditions in natural open, natural covered (with vegetation) and artificial nests, and assessed the relationship between nest characteristics (type, age, distance from the coast, orientation and entrance opening) and in-nest ectoparasite infestations and the health of African penguins in Stony Point, South Africa. Penguins (50 adults and 192 chicks) and their nests (n = 308) were sampled in 2016 and 2017. Soil temperature was higher in artificial than in natural nests, and soil and nest material moisture was lower in artificial and natural covered nests than natural open. Ectoparasite infestations were higher under warmer and drier conditions, in artificial nests and nests near the coastline. Penguin (adult and chick) body mass and chick body condition were lower in warmer nests and total plasma protein (in adults and checks) was lower in drier nests. Given the potential adverse effects of ectoparasites on host species, it is recommended that conservation agencies implement a monitoring programme to assess the ectoparasite infestation in artificial nests across multiple colonies. This information will facilitate a more holistic penguin conservation management plan that may prevent further detrimental effects on this endangered penguin species.

Comparative morphometric evaluation of hepatic hemosiderosis in wild Magellanic penguins (Spheniscus magellanicus) infected with different Plasmodium spp. subgenera / Avaliação morfométrica comparativa da hemossiderose hepática em pinguins-de-Magalhães (Spheniscus magellanicus) de vida livre infectados por diferentes subgêneros de Plasmodium spp

Abstract Avian malaria is one of the most important diseases of captive penguins. We employed morphometric techniques to evaluate hepatic hemosiderosis in rehabilitating wild Magellanic penguins (Spheniscus magellanicus) that were negative (n = 9) or naturally infected by different subgenera of Plasmodium spp. (n = 24), according with: Plasmodium subgenera (Haemamoeba, Huffia, Other lineages, and Unidentified lineages), severity of Plasmodium histopathological lesions, and concurrent diseases, age class (juvenile or adult plumage), sex (male, female or not determined), body score (emaciated, thin, good, excellent, not available), molt, presence or absence of oil contamination upon admission, iron supplementation, and rehabilitation center. The percentage of the area occupied by hemosiderin was called 'Index of Hepatic Hemosiderosis (IHH)'. Plasmodium-positive females presented significantly higher IHH values (17.53 ± 12.95%) than males (7.20 ± 4.25%; p = 0.041). We observed higher levels of congestion (p = 0.0182) and pneumonia (p = 0.0250) severity between Unidentified lineages vs. Huffia. We believe that the hepatic hemosiderosis observed in this study was multifactorial, the result of pathological processes caused by malaria, molting, hemoglobin and myoglobin catabolism during migration, anemia, concomitant diseases, and iron supplementation, all possibly potentiated by decreased liver mass. Further studies are needed to clarify the mechanisms of these hypotheses.

Resumo Malária aviária é uma das mais relevantes doenças em pinguins cativos. Foram aplicadas técnicas morfométricas para avaliar a hemossiderose hepática em pinguins-de-Magalhães (Spheniscus magellanicus ) de vida livre em reabilitação negativos (n = 9) e naturalmente infectados por diferentes subgêneros de Plasmodium spp. (n = 24), quanto a: subgênero de Plasmodium (Haemamoeba , Huffia, Outras Linhagens, e Linhagens não identificadas), severidade das lesões histopatológicas causadas por Plasmodium e doenças concomitantes, faixa etária (plumagem juvenil ou adulta), sexo (macho, fêmea, indeterminado), condição corporal (emaciado, magro, bom, excelente, indisponível), muda, presença/ausência de óleo a admissão, suplementação de ferro, e centro de reabilitação. A porcentagem da área ocupada por hemossiderina foi denominada "Índice de Hemossiderose Hepática (IHH)". Fêmeas Plasmodium -positivas apresentaram IHH significativamente mais elevado que machos, respectivamente, 17,53 ± 12,95% e 7,20 ± 4,25% (p = 0,041). Níveis mais elevados de congestão (p = 0,0182) e pneumonia (p = 0,0250) foram observados entre Linhagens não identificadas vs. Huffia. Possivelmente, a hemossiderose hepática observada nesse estudo seja multifatorial, resultado de processos patológicos causados por malária, muda, catabolismo de hemoglobina e mioglobina durante a migração, anemia, doenças concomitantes e suplementação de ferro, potencialmente intensificados por massa hepática reduzida. Estudos complementares são necessários para esclarecer os mecanismos de tais hipóteses.

Comparative morphometric evaluation of hepatic hemosiderosis in wild Magellanic penguins (Spheniscus magellanicus) infected with different Plasmodium spp. subgenera.

Avian malaria is one of the most important diseases of captive penguins. We employed morphometric techniques to evaluate hepatic hemosiderosis in rehabilitating wild Magellanic penguins (Spheniscus magellanicus) that were negative (n = 9) or naturally infected by different subgenera of Plasmodium spp. (n = 24), according with: Plasmodium subgenera (Haemamoeba, Huffia, Other lineages, and Unidentified lineages), severity of Plasmodium histopathological lesions, and concurrent diseases, age class (juvenile or adult plumage), sex (male, female or not determined), body score (emaciated, thin, good, excellent, not available), molt, presence or absence of oil contamination upon admission, iron supplementation, and rehabilitation center. The percentage of the area occupied by hemosiderin was called 'Index of Hepatic Hemosiderosis (IHH)'. Plasmodium-positive females presented significantly higher IHH values (17.53 ± 12.95%) than males (7.20 ± 4.25%; p = 0.041). We observed higher levels of congestion (p = 0.0182) and pneumonia (p = 0.0250) severity between Unidentified lineages vs. Huffia. We believe that the hepatic hemosiderosis observed in this study was multifactorial, the result of pathological processes caused by malaria, molting, hemoglobin and myoglobin catabolism during migration, anemia, concomitant diseases, and iron supplementation, all possibly potentiated by decreased liver mass. Further studies are needed to clarify the mechanisms of these hypotheses.