Page 317 - Atlas Sea Birds Ver1

3.2 Numbers, trends, status, and conservation of African Penguin
(Spheniscus demersus)

Authors: AB Makhado, DB Tom, BM Dyer, M Masotla, L Upfold, and RJM Crawford
Abstract:
African Penguins (Spheniscus demersus) are endemic to southern Africa, where they have bred, or attempted to, at 39 sites in the
Benguela upwelling system (BUS): 16 in Namibia and 23 in South Africa. Their overall population decreased from some 0.5–1 million
pairs in the early 1900s to c. 141,000 pairs in 1956, c. 51,500 pairs in 1989, and only 14,800 pairs in 2020–2022. The decrease up until
1956 mainly resulted from unsustainable exploitation of their eggs. More recently, decreases were largely driven by a reduced abundance
and availability of their main prey species, sardine (Sardinops sagax) and anchovy (Engraulis encrasicolus), for which they compete
with the region’s purse-seine fisheries. Other factors that adversely influenced African Penguins included oil spills (including from ship-
to-ship bunkering), human disturbance at breeding sites, displacement from nests and predation by Cape Fur Seals (Arctocephalus
pusillus pusillus), losses to avian, feral, and mainland predators, disease, severe weather, and seismic surveys. African Penguins have a
generation length of 10 years and, given the large and ongoing decrease in their overall population, were in 2022 classified as Endangered
by the International Union for Conservation of Nature.

Introduction:
African Penguins (Spheniscus demersus) are endemic to southern Africa, where they have bred at 39 sites (Figure 1) within the Benguela
upwelling system (BUS; Crawford et al. 2013, Sherley et al. 2020). At the start of the 20 century they were the regions’ most abundant
th
seabird, with numbers at Dassen Island (where they were especially numerous; Kearton 1931), estimated to be 570,000–926,000 breeding
pairs (Shannon and Crawford 1999, Crawford et al. 2007). However, their eggs were harvested in an unsustainable manner (c. 48% of
those produced; Shannon and Crawford 1999) and by 1956 their overall population had decreased to about 141,000 pairs (Shelton et al.
1984). Egg harvests were terminated in 1967 (Makhado et al. 2024).
Since then, trends in African Penguins have been substantially influenced by the abundance or availability of two of their main prey
species, sardine (Sardinops sagax) and anchovy (Engraulis encrasicolus), which are also heavily exploited by the purse-seine fisheries
of Namibia and South Africa (Rand 1960, Crawford et al. 2011, 2022, Sherley et al. 2020). Following a collapse of Namibia’s sardine
resource in the 1960s and 1970s, there was a large decrease in numbers of African Penguins breeding in that country (Crawford 2007).
At the recent turn of the century there were shifts to the southeast of sardine and anchovy off South Africa (Fairweather et al. 2006, Roy et
al. 2007). These were associated with reduced numbers of African Penguins breeding at South African colonies west of Cape Agulhas but
increased numbers nesting in Algoa Bay (Crawford et al. 2014). Between 1979 and 2019 colonies in Algoa Bay went from holding c. 25%
to c. 40% of the overall population because their numbers decreased less rapidly than elsewhere (Sherley et al. 2020). However, colonies
in Algoa Bay recently collapsed so that from 2020–2022 the species’ population fell to c. 14,800 pairs. Although African Penguins also
feed on other prey items, including bearded goby (Sufflogobius bibarbatus) (Crawford et al. 1985, Ludynia et al. 2010) and cephalopods
(Connan et al. 2016), these have lower energy value than sardine and anchovy (Ludynia et al. 2010, Dyer et al. 2019).
This chapter collates estimates of numbers of African Penguins breeding at different sites in southern Africa, and briefly reviews the
species’ conservation status, identifies Important Bird and Biodiversity Areas (IBAs) for, and summarises threats to, this species.

Numbers, trends and conservation status
Records of African Penguins breeding at sites in different 72,500 pairs at Dassen Island in 1956. Possession, Dyer,
years from 1576–2022 are shown in Table 1. Information and St Croix islands also had maxima > 15,000 pairs.
was collated from Rand (1952, 1960, 1963a, b), Jarvis and In the same period, 14 other sites had maxima > 1,000
Cram (1971), Berry et al. (1974), Every (1983), Shelton pairs: Mercury, Ichaboe, Halifax, Pomona, Plumpudding,
et al. (1984), Loutit and Boyer (1985), Loutit et al. (1986), and Sinclair islands in Namibia; Malgas, Marcus, Jutten,
Williams and Dyer (1990), Crawford et al. (1995, 1999, Vondeling, Robben, and Bird (Algoa Bay) islands and two
2000b, 2001, 2007, 2011, 2013), Whittington et al. (1996), mainland sites, Simon’s Town and Stony Point, in South
Cordes and Crawford (1999), Bartlett et al. (2003), Hagen Africa (Table 1). One pair attempted to breed at Cape
(2015), Kemper (2015), Underhill et al. (2006), Kemper et
al. (2007), Sherley et al. (2020) and breeding site chapters
in this volume.
When multiple counts were obtained at a site in a given
year, the maximum was used. African Penguins breed
throughout the year with peaks in breeding varying around
the coastline (Crawford et al. 2013). They often replace lost
clutches or have two broods so their breeding season is
protracted (Randall and Randall 1981) and counts may miss
peaks. African Penguins moult annually, replacing all their
feathers. In order to achieve this, they are ashore and fast
for c. 21 days. Therefore, they need to undertake extensive
pre- and post-moult fattening trips that last for 35–42 days.
Failure to obtain sufficient food leads to mortality (Randall
and Randall 1981). From 1956 to 2022 the largest number
of African Penguins observed breeding at a site was about An African Penguin nest at Schaapen Island 2012 (photo BM Dyer)

311