Health evaluation of African penguins (<i>Spheniscus demersus</i>) in southern Africa

Abstract

The African penguin (Spheniscus demersus) is an endangered seabird that breeds along the coast of Namibia and South Africa, and disease surveillance was identified as a priority for its conservation. Aiming for the establishment of baseline data on the presence of potential pathogens in this species, a comprehensive health assessment (blood smear examination, haematology, biochemistry and serology) was conducted on samples obtained from 578 African penguins at 11 breeding colonies and a rehabilitation centre. There were 68 penguins that were seropositive for at least one of seven pathogens tested: avian encephalomyelitis virus, avian infectious bronchitis virus, avian reovirus, infectious bursal disease virus, Newcastle disease virus, Mycoplasma gallisepticum and Mycoplasma synoviae. All samples were seronegative for avian influenza virus subtypes H5 and H7 and infectious laryngotracheitis virus. The apparent prevalence of Babesia sp. and Borrelia sp. in blood smears was consistent with previous studies. Babesia-infected individuals had a regenerative response of the erythrocytic lineage, an active inflammatory response and hepatic function impairment. These findings indicate that African penguins may be exposed to conservation-significant pathogens in the wild and encourage further studies aiming for the direct detection and/or isolation of these microorganisms.

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

“…Blood parasites were remarkably common in African penguins examined in this study, with Babesia being the most frequent (46% prevalence on admission, 72% infection ratio), whereas Borrelia was recorded only sporadically (1% prevalence on admission, 3% infection ratio) and Plasmodium was only recorded once. Although these parasites have long been known to infect wild African penguins (Coles, 1941; Fantham and Porter, 1944), their prevalence in this study was markedly higher than in apparently wild healthy adult African penguins sampled in previous studies (Parsons et al ., 2016; Espinaze et al ., 2019).…”

“…Borrelia infections are significantly associated with a decreased survival probability in African penguin chicks admitted for rehabilitation at SANCCOB (Vanstreels et al, 2019), and in some cases, Borrelia infections are lethal to penguins (Yabsley et al, 2012;Parsons et al, 2018b). Although Babesia infections have yet to be implicated in the death of African penguins, they have been linked to haematological abnormalities in otherwise apparently healthy African penguins (Parsons et al, 2016) and their potential lethality has been demonstrated in other penguin species (Parsons et al, 2017(Parsons et al, , 2018b. Furthermore, the flea P. longicornis is speculated to serve as a mechanical facilitator to the transmission of Avipoxvirus to penguins (Kane et al, 2012).…”

Serological Survey for Select Infectious Agents in Wild Magellanic Penguins (Spheniscus Magellanicus) in Argentina, 1994–2008

“…There are no studies conclusively demonstrating Avian orthoreovirus infection in penguins, but Gough et al (2002) isolated reovirus-like particles from the tissues of African Penguins that died with gastrointestinal and respiratory lesions at a zoo in the UK. Previous surveys of Avian orthoreovirus in penguins found seroprevalences ranging from 0% to 23% (Karesh et al 1999;Travis et al 2006;Smith et al 2008;Parsons et al 2016). In addition, antibodies to this pathogen were also reported in other seabirds that share breeding habitat with Magellanic Penguins in Patagonia (Gallo et al 2013), and it therefore seems likely that wild penguins are sporadically exposed to Avian orthoreovirus.…”

“…Given the low positive predictive value, we would interpret our findings as potentially false positive results. In contrast, enzyme-linked immunosorbent assay (ELISA) testing of African Penguins for antibodies against this virus found seroprevalence ranging from 1% to 5% in wild populations (Parsons et al 2016). It is unclear, however, whether these serological results can be attributed to exposure to Tremovirus A or to cross-reactivity with other antigenically similar agents.…”

An exploration of rhythm perception in African penguins (Spheniscus demersus)

“…African penguins' vocalizations and the information they carry are important to social recognition, and ultimately the survival of their species (Favaro et al, 2015 (Parsons, Schaefer & Vanstreels, 2016;Sherley et al, 2013). The reason for this population decline is due mostly to low food availability, and breeding success that is inadequate to sustain their population (Crawford et al, 2003).…”