Determinants of external and blood parasite load in African penguins () admitted for rehabilitation.

We investigate the factors associated with the occurrence and abundance of external and blood parasites in African penguins (Spheniscus demersus), an endangered seabird that breeds exclusively on the coasts of Namibia and South Africa. External parasites were collected using the dust-ruffling method from 171 African Penguins admitted at a rehabilitation facility in the Western Cape, South Africa. Additionally, blood smears were obtained upon admission and weekly during rehabilitation and examined for blood parasites. Fleas Parapsyllus longicornis humboldti, ticks Ornithodoros capensis and lice Austrogoniodes demersus were recovered from 93, 63 and 40%, respectively, of the penguins upon admission to the centre. Rescue location and age group were identified as significant determinants of flea abundance, whereas month of admission was a significant determinant of tick abundance. Blood parasites were also common on admission, with Babesia being the most frequent (46% prevalence) whereas Borrelia was recorded sporadically (1.2%) and Plasmodium was recorded once. The prevalence and abundance of ticks on admission was positively associated with Babesia infection on admission. Our findings demonstrate the variability and contributing factor of parasite infections in an endangered species of penguin, and highlight the need for additional research on the parasite-host dynamics involving these potential disease vectors.