Avian malaria affecting penguins in zoological gardens, aquariums and wildlife parks in the UK

Abstract

Background: Avian malaria has caused mortalities in captive penguins worldwide and it is a conservation threat for some wild penguins. The experience of staff working on penguins is highly valuable for the improvement of captivity conditions. Methods: An online questionnaire was designed to collect avian malaria information in penguins in the UK. Volunteers with diverse experience reviewed it for scientific value and clarity, and it was supported by the British and Irish Association of Zoos and Aquariums. Results: Forty-two institutions were contacted by email, obtaining 27 complete and five partial responses. Eighteen institutions reported avian malaria in 38 suspected and 37 confirmed outbreaks in the past 20 years, mainly occurring in the summer and recent years. Proportional risk was higher in the south east region of England. Humboldt and African penguins were more commonly affected, and prevalence was mostly low or medium, but lethality was high. Different treatment protocols were reported with inconsistent outcomes. Conclusions: Penguins' susceptibility, their translocation across institutions, and the wide distribution of avian malaria make this disease a constant threat. Preventive and control measures are recommended, including testing for early diagnosis and treatment, avoiding prolonged stressful events in penguins, and monitoring and controlling mosquito vectors.This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Avian Malaria in Penguins: Diagnostics and Future Direction in the Context of Climate Change

“…This is thought to primarily reflect the parasitic species present in native wild bird populations, rather than a distinct sensitivity of the local penguins to these species [ 7 ]. Infections with avian malaria have been reported in the Northern ( Eudyptes moseleyi ) and Southern ( Eudyptes chrysocome ) Rockhopper, King ( Aptenodytes patagonicus ), Humboldt ( Spheniscus humboldti ), African ( Spheniscus demersus ), Magellanic ( Spheniscus magellanicus ), Snares ( Eudyptes robustus ), Little ( Eudyptula minor ), Yellow eyed ( Megadyptes antipodes ), Chinstrap ( Pygoscelis antarcticus ), Macaroni ( Eudyptes chrysolophus ), and Gentoo ( Pygocelis papua ) penguins [ 5 , 6 , 10 , 11 , 12 , 13 ]. Humboldt ( Spheniscus humboldti ) and African ( Spheniscus demersus ) penguins seem to be the most frequently affected, although this likely reflects a bias towards keeping those species in captivity [ 10 ].…”

“…Infections with avian malaria have been reported in the Northern ( Eudyptes moseleyi ) and Southern ( Eudyptes chrysocome ) Rockhopper, King ( Aptenodytes patagonicus ), Humboldt ( Spheniscus humboldti ), African ( Spheniscus demersus ), Magellanic ( Spheniscus magellanicus ), Snares ( Eudyptes robustus ), Little ( Eudyptula minor ), Yellow eyed ( Megadyptes antipodes ), Chinstrap ( Pygoscelis antarcticus ), Macaroni ( Eudyptes chrysolophus ), and Gentoo ( Pygocelis papua ) penguins [ 5 , 6 , 10 , 11 , 12 , 13 ]. Humboldt ( Spheniscus humboldti ) and African ( Spheniscus demersus ) penguins seem to be the most frequently affected, although this likely reflects a bias towards keeping those species in captivity [ 10 ]. The species in which infection is not reported typically do not encounter the vector, as they are native to regions inhospitable to mosquitos (Antarctica in particular) and have either not been kept in captivity or are maintained in mosquito-proof captive environments.…”

“…Infection is less common in wild birds when compared with captive birds in endemic habitats, likely related to the immunosuppressive circumstances surrounding captivity (e.g., morbidity leading to rehabilitation, stress, movement, etc. ), as well as the relative freedom of movement and environmental conditions (particularly wind) experienced by free-range penguins [ 10 ]. Despite this, infections with parasites of the genus Plasmodium have been reported in several wild penguin colonies ( Table 1 ).…”

“…The long-term impact of chronic infection with Plasmodium parasites is not currently fully understood. Due to the typically acute nature of the disease in penguins there is a marked absence of information in this area [ 10 ]. Therefore, our understanding is based on work performed in other avian species.…”

“…In addition, their relative tolerance for infection may also facilitate the evolution of more virulent Plasmodium species [ 1 , 2 , 27 ]. This local reservoir of infection makes eradication and prevention of disease in captive birds highly challenging [ 10 , 28 ].…”