Avian Malaria Affecting Penguins in Zoological Gardens, Aquariums and Wildlife Parks in the UK

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.