What is the Problem?
- The African penguin is in crisis – they were first classified by the IUCN as Endangered in 2010 and their population continues to decline (BirdLife International 2020)
- African penguins have been identified by the IUCN Penguin Specialist Group as one of three (of the global 18 species of penguin) that require urgent conservation intervention (Boersma et al. 2019)
- In 2019, a population assessment was conducted to evaluate their conservation status and assess whether the species met the threshold for Endangered. This assessment confirmed it had, with the global population declining by nearly 65% since 1989 (Sherley et al. 2020).
- This assessment was updated following the completion of the South African 2021 annual census. Over the last 30 years (three generations), the number of African penguins breeding in South Africa has declined by 73% from ~42,500 breeding pairs in 1991 to ~10,400 pairs in 2021 (Sherley et al. 2021). This represents a loss of almost a quarter of the remaining penguin population in the space of two years (Sherley et al. 2021).
- The global population is now estimated at 14,700 pairs in total; ~10,400 pairs in South Africa (based on 2021 breeding census) and ~4,300 pairs in Namibia (based on 2019 breeding census).
- Based on rates of population decline at the time, it was predicted that the population along the West Coast of South Africa could be functionally extinct by 2035 should no further actions be implemented. (Sherley et al. 2018).
- To provide a broader historical context of the extent of this population decline, while the total population at the turn of the 20th century is not known, it is estimated that there could have been as many as 1.5million to 3million individuals throughout the species range, with an estimate of 0.3 million pairs at Dassen Island (Crawford et al. 2007; Frost et al. 1976; Shannon and Crawford 1999). By 1956, only an estimated 0.3 million individuals remained (Crawford et al. 2007).
- Essentially, the African penguin has lost nearly 97% of its population. Put another way, it is at less than 3% of its historical levels in the wild.
- While the overall population trends are alarming, it is also important to consider what is taking place at individual colonies. African penguins are colonial nesting birds, and this breeding behaviour provides a range of benefits.
- Five South African colonies have become extinct since 2005 (a rate of loss of one colony every three years (DFFE unpubl. Data).
- In 2004, three of the South African colonies had more than 5,000 breeding pairs, with Dassen Island holding about 25,000 pairs; St Croix Island approximately 10,000 pairs and Robben Island nearly 8,000 pairs (DFFE, unpubl. data).
- All the large colonies have experienced substantial decreases with none of the remaining colonies having more than 5,000 pairs (DFFE unpubl. Data).
- Smaller colonies have a higher risk of going extinct than larger ones (Makhado et al. 2021).
- This is because as colonies get smaller, they become more susceptible to Allele effects, or inverse density dependence, reducing their chances of recovery and increasing their likelihood of extinction (Makhado et al. 2021).
- As the small breeding groups at breeding colonies get smaller, more birds nest near colony edges, where eggs and chicks are at greater risk to predation (e.g. Cordes et al. 1999).
- Declining penguin numbers at colonies may reduce information acquisition that facilitates food-finding (e.g. Wakefield et al. 2013).
What went Wrong?
- The historical practice of egg collection in the 1800s and 1900s had a significant impact on recruitment to the African penguin population during the early 20th century (Shannon and Crawford 1999).
- African penguins used to primarily make nests in guano burrows. However, the large-scale collection of guano from seabird breeding colonies not only disturbed breeding penguins, but also destroyed this breeding habitat, causing penguins to breed in sup-optimal breeding habitats (Frost et al. 1976b, Wilson and Wilson 1989, Lei et al. 2014).
- Extreme weather events, exacerbated by climate change can cause flooding from rain or storm surges, which results in egg and chick loss. Extreme heat events can lead to nest abandonment by adults, where eggs and chicks can be lost to predation. Chicks can also die from hypo and hyperthermia.
- Penguins are oiled through large scale catastrophic events, chronic oiling and ship-to-ship bunkering (transfer of fuel at sea). While oiled African penguins can be successfully rescued, rehabilitated and released, some penguins suffer long-term physiological damage as a result of ingesting oil, which has an impact on their survival and breeding performance (Wolfaardt 2009, 2008, Barham et al. 2007).
- Penguins are exposed to various disturbances from people such as ill-behaved tourists and are killed by cars particularly at parking lots at mainland colonies (SANParks, CapeNature, City of Cape Town unpubl. data).
- Adult, juvenile and fledgling African penguins are predated on at sea by Cape fur seals (Makhado 2009, Makhado et al. 2013, Weller et al. 2016), and Kelp gulls predate unguarded eggs and small chicks. Predation by caracal, leopard and mongoose has been observed at mainland colonies (e.g. Underhill et al. 2006, Vanstreels et al. unpublished data, CCT, SANParks and CN, unpublished data). Predation by feral cats and domestic dogs has also been observed at some colonies (Weller et al. 2014, 2016)
- While mortality in the wild from disease had not been substantial thus far, recently Avian Influenza has caused mortality of over 300 African penguins in Namibia and African penguins in South Africa have been affected by two different outbreaks in the last 3 years (Khomenko et al. 2018, Molini et al. 2019).
- Entanglement in marine pollution such as fishing line also cause mortalities.
- Recently, concern has been raised as to the impact of noise from boat traffic on African penguins
- The various colonies experience these threats in different frequencies and intensities. Lack of sufficient food is however considered as the main driver of the current decline (BirdLife International 2020). This has been attributed to food shortages caused by declining fish stocks; shifts in the distribution of prey species and competition with commercial purse seine fisheries for food (e.g. Crawford et al. 2011, 2018).
- African penguins feed on small pelagic fish, primarily sardine and anchovy, and the abundance of these fish has been shown to impact their breeding success (Crawford et al. 2006a, Sherley et al. 2013), adult survival (Sherley et al. 2013, Robinson et al. 2015) and juvenile survival (Weller et al. 2016).
- Furthermore, it has been suggested that the biomass of these stocks may often be too low off South Africa’s west coast to maintain population equilibrium (Weller et al. 2014, 2016). It is during these times of low biomass levels that competition between penguins and fisheries may have greater impact.
- Sherley et al. (2017), found evidence of a marine ecological trap. Dispersing juvenile African penguins were shown to travel large distances to areas of low sea surface temperatures and high chlorophyll-a. These areas now have depleted forage fish stocks due to climate change and industrial fishing and so are no longer reliable indicators of fish availability.
WHAT IS BEING DONE?
In mitigating the various threats at the colonies, the following actions are taking place, led by the colony Managing Authorities and in collaboration with their conservation partners:
- Poor breeding habitat: providing increased shade by vegetating breeding colonies; provision of artificial nest boxes and evaluating success of nest boxes.
- Extreme climatic events: shade provision; digging culverts to divert water to prevent flooding; placing sand bags to prevent flooding from storm surges; development of early warning systems (SANParks Climate change team with SANCCOB support at Boulders).
- Oiling: improving response times and activities, and rehabilitation techniques; lobbying against additional ship-to-ship bunkering licences; rescuing oiled birds and their rehabilitation and release back to the wild.
- Predation: removal of individual damage causing animals.
- Disease: rescuing diseased birds, rehabilitation and release; continuous disease surveillance in colonies.
- Poor food availability: rescuing starving penguins, rehabilitation and release; the establishment of an African penguin colony at De Hoop Nature Reserve that aims to provide a safe breeding area closer to an important food area.
- Human disturbance is minimised at the colonies.
- Penguin Rangers: Any oiled, injured, ill or abandoned penguins that our rangers or the managing authorities’ rangers identify and rescue are transported to SANCCOB for veterinary intervention and rehabilitation until release criteria are met. SANCCOB funds and deploys additional rangers to some of the African penguin breeding colonies to provide additional capacity to the Managing Authorities.
What still needs to be done to prevent penguin mortality and encourage population recovery?
Everything that can be done on land to reduce mortality and improve breeding success is being done by Managing Authorities and their conservation partners, and these actions need to continue within an adaptive management framework. There are still some aspects that require additional attention in order to reduce the African penguin population decline and promote the species’ recovery. One of these is improving food availability.
A thirteen year project led by the South African government aims to investigate the benefit to breeding African penguins and their chicks by closing areas around islands to fishing. While results are not uniform across colonies, analyses indicate that there is a biologically meaningful benefit to these fishing closures, particularly with respect to chick survival and chick condition (parameters important to the demographic process), as well as maximum foraging distances travelled.
However, these results are not supported by some, and the South African government is working extremely hard to resolve this issue and find a way forward through a process led by Minister Creecy, who is the Minister of Forestry and Fisheries and Environmental Affairs in the South Africa.
All African penguins undergo a catastrophic annual moult; they need to replace all their feathers in order to maintain their waterproofing. During this moult, they are land-bound for ~21 days and do not eat. Prior to this moult fast, they have to acquire sufficient fat reserves in order to survive and this requires a 4-5 week period of foraging at sea to consume enough food to survive their moult. Subsequent to the fast, they return to sea to regain their body condition. The moult phase is thus energetically expensive and is one of the most sensitive times of the penguin’s life cycle. Ensuring penguins have enough food to survive this moult is critical and BirdLife South Africa is leading a research programme to determine important feeding areas for pre- and post-moulting African penguins.
Once the fledging African penguins leave their colony, they remain at sea for 18-24 months before returning to moult into their adult plumage. Research has shown that these dispersing penguins travel to areas that have poor food resources, impacting their survival. Juvenile survival is thus low in these populations.
Decisions to ensure sufficient food for African penguins (in fact all top predators in the Benguela Upwelling Ecosystem) thus need to take place at spatial and temporal scales that take their full life cycle into consideration.
Another threat that needs attention is addressing and mitigating the threat that ship-to-ship bunkering, and other shipping activities, have on African penguins.
Image of Halifax, courtesy of Thomas P. Peschak_National Geographic
WHAT IS THE IMPACT OF AFRICAN PENGUINS GOING EXTINCT?
What still needs to be done to prevent penguin mortality and encourage population recovery?
- African penguins transfer large amounts of nutrients from the ocean to their colonies, influencing the functioning of the island/colony ecosystem and adjacent marine areas.
- Their guano is washed into the sea, promoting algal growth, influencing the growth of intertidal communities which support shorebirds and other marine invertebrates.
- They improve access to food for other species, eg herding schools of fish upwards where other birds can deed on them (McInnes et al. 2017).
- The African penguin is Africa’s only penguin species, and one of 18 global penguin species.
- They are sentinels of the ocean (Boersma 2008) and the African penguin is thus a symbol South Africa’s marine ecosystem and its health.
- The African penguin plays a significant role in South Africa’s ecotourism offering
- In the Western Cape, there are tourist attractions at the Simon’s Town colony, which includes Boulders in Table Mountain National Park, and the Stony Point colony in Betty’s Bay.
- Economic benefits associated with these land-based colonies include income generated though entrance fees, job provision at the colonies as well as other benefits to surrounding areas (e.g. restaurants, accommodation, transport services).
- The total expenditure associated with the Simon’s Town colony is estimated at approximately R311 million per annum and generates 885 jobs (van Zyl and Kinghorn 2018). The projected future income from tourism at the Simon’s Town colony over the next 30 years was estimated at approximately R6.8 billion (pre-Covid-19 figures).