African penguin

Roughly 4 million African penguins existed at the beginning of the 19th century. Of the 1.5 million African penguins estimated in 1910, only some 10% remained at the end of the 20th century. African penguin populations, which breed in Namibia and South Africa, have declined by 95 percent since pre-industrial times.[13]

Today, their breeding is largely restricted to 24 islands from Namibia to Algoa Bay, South Africa,[14] with the Boulders Beach colony being an exception to this rule.

The total population fell to approximately 150,000–180,000 in 2000.[15][16] Of those, 56,000 belonged to the Dassen Island colony and 14,000 to the Robben Island colony.[17] The colony at Dyer Island in South Africa fell from 46,000 in the early 1970s to 3,000 in 2008.[18]

In 2008, 5,000 breeding pairs were estimated to live in Namibia.

In 2010, the total African penguin population was estimated at 55,000. At the rate of decline seen from 2000 to 2010, the African penguin is expected to be extinct in the wild by 2026.[19]

In 2012, about 18,700 breeding pairs were estimated to live in South Africa, with the majority on St. Croix Island in Algoa Bay.[1][20]

The total breeding population across both South Africa and Namibia fell to a historic low of about 20,850 pairs in 2019.[21]

African penguins forage in the open sea, where they pursue pelagic fish such as sardines and anchovies (specifically the Southern African anchovy),[22] and marine invertebrates such as squid and small crustaceans.[23] Penguins normally swim within 20 km (12 mi) of the shore.[6] A penguin may consume up to 540 grams (1.19 lb) of prey every day,[24] but this may increase to over 1 kg (2.2 lb) when raising older chicks.[23]

Due to the collapse of a commercial pilchard (sardine) fishery in 1960, the African penguin's diet has shifted towards anchovies to some extent, although available pilchard biomass is still a notable determinant of penguin population development and breeding success. While a diet of anchovy appears to be generally sufficient, it is not ideal due to anchovies' lower concentrations of fat and protein. Penguin diet changes throughout the year; as in many seabirds, it is believed that the interaction of diet choice and breeding success helps the penguins maintain their population size. Although parent penguins are protective of their hatchlings, they will not incur nutritional deficits themselves if prey is scarce and hunting requires a greater time or energy commitment. This may lead to higher rates of brood loss under poor food conditions.

When foraging, African penguins carry out dives that reach an average depth of 25 m (82 ft) and last for 69 s, although a maximum depth of 130 m (430 ft) and duration of 275 s has been recorded.[25]

Egg from the collection of Museum Wiesbaden

Nesting burrows of the African penguin, Boulders Beach (2017)

The African penguin is monogamous.[5] It breeds in colonies, and pairs return to the same site each year. The African penguin has an extended breeding season,[5] with nesting usually peaking from March to May in South Africa, and November to December in Namibia.[22] A clutch of two eggs are laid either in burrows dug in guano, or scrapes in the sand under boulders or bushes. Incubation is undertaken equally by both parents for around 40 days. At least one parent guards the chicks for about one month, whereafter the chicks join a crèche with other chicks and both parents head out to sea to forage each day.

Chicks fledge at 60 to 130 days, the timing depending on environmental factors such as the quality and availability of food. The fledged chicks then go to sea on their own, where they spend the next one to nearly two years. They then return to their natal colony to molt into adult plumage.[5]

When penguins molt, they are unable to forage as their new feathers are not yet waterproof; therefore, they fast over the entire molting period.[5] African penguins take around three weeks to molt, and lose almost half their body weight by using up their fat reserves in the process.[26]

Female African penguins remain fertile for 10 years. African penguins spend most of their lives at sea until it comes time for them to lay their eggs. Due to high predation on the mainland, African penguins will seek protection on offshore islands, where they are safer from larger mammals and natural challenges. These penguins usually breed during the winter when temperatures are lower. African penguins often will abandon their eggs if they become overheated in the hot sun, and abandoned eggs do not survive the heat. Ideally, eggs are incubated in a burrow dug into the guano layer (which provides suitable temperature regulation), but the widespread human removal of guano deposits has rendered this type of nest unfeasible at many colonies. To compensate, penguins dig holes in the sand, breed in the open, or make use of nest boxes if they are provided. The penguins spend three weeks on land to provide for their offspring, after which chicks may be left alone during the day while the parents forage. The chicks are frequently killed by predators or succumb to the hot sun. The eggs are three to four times bigger than hen's eggs. Parents usually feed hatchlings during dusk or dawn.

In 2015, when foraging conditions were favorable, more male than female African penguin chicks were produced in the colony on Bird Island. Male chicks also had higher growth rates and fledging mass, and therefore may have higher post-fledging survival than females. This, coupled with higher adult female mortality in this species, may result in a male biased adult sex ratio and may indicate that conservation strategies focused on benefiting female African penguins may be necessary.[27]

The average lifespan of an African penguin is 10 to 27 years in the wild, and up to 30 in captivity.[28]

Primary predators of African penguins include sharks and fur seals. While nesting, kelp gulls, mongooses, caracals, Cape genets and domestic cats and dogs may prey on the penguins and their chicks.[29][30] Mortality from terrestrial predators is higher if penguins are forced to breed in the open in the absence of suitable burrows or nest boxes.

African penguin eggs were considered a delicacy, and were still being collected for sale as recently as the 1970s. In the 1950s, they were being collected from Dassen Island and sold in nearby towns.[31] In 1953, 12,000 eggs were collected.[32] In the late 1950s, some French chefs expressed interest in recipes including African penguin eggs collected from the islands off South Africa's west coast, and placed annual orders for small quantities.[33][34][35] In the mid 1960s, eggs were collected in the thousands and sold by the dozen,[36] with each customer limited to two dozen eggs in total.[37]

The practice of collecting African penguin eggs involved smashing those found a few days prior to a collecting effort to ensure that only freshly laid eggs were sold. This added to the drastic decline of the African penguin population around the Cape coast, a decline which was hastened by the removal of guano from islands for use as fertiliser, eliminating the burrowing material used by penguins.[38]

Penguins remain susceptible to pollution of their habitat by petrochemicals from spills, shipwrecks and cleaning of tankers while at sea. Accounts of African penguins impacted by oil date back to the 1930s.[39] African penguins' exposure to oil spills is both chronic (higher frequency small discharges of oil at sea) and acute (rare maritime disasters where large volumes of oil are released in a single event). Penguins of many species have been impacted by oil spills across the southern hemisphere.

In 1948, the tanker Esso Wheeling sank, subsequently oiling and killing thousands of penguins of the Dyer Island colony.[40] In 1953, dead penguins were among a range of dead birds, fish and other marine life that washed ashore after the tanker Sliedrecht was holed and spilled oil near Table Bay.[41] In 1971, the SS Wafra oil spill impacted the African penguin colony of Dyer Island. In 1972, oil spilled following the Oswego-Guardian and Texanita collision oiled roughly 500 penguins.[42] In 1975, newspapers reported that oil pollution from shipwrecks and the pumping of bilges at sea had killed tens of thousands of African penguins. At the time, the Dassen Island colony was being passed by 650 oil tankers each month[43] because the Suez Canal had become blocked with wrecked vessels, thus increasing maritime traffic past the Cape of Good Hope.[42]

In 1979, an oil spill prompted the collection and treatment of 150 African penguins from St. Croix Island near Port Elizabeth. The animals were later released at Robben Island and four of them promptly swam back to St. Croix Island, surprising scientists.[44][45]

In 1983, the exposure of penguins of Dassen Island to the oil slick from the Castillo de Bellver was also a topic of concern given the penguins' conservation status at the time, but owing to prevailing wind and current, only gannets were oiled.[46]

African penguin casualties were significant following the sinking of the MV Apollo Sea and subsequent oil slick in 1994. 10,000 penguins were collected and cleaned, of which less than half survived.[47]

Disaster struck on 23 June 2000, when the iron ore tanker MV Treasure sank between Robben Island and Dassen Island, South Africa. It released 400–1,000 tonnes (390–980 long tons; 440–1,100 short tons) of fuel oil, causing an unprecedented coastal bird crisis and oiling 19,000 adult penguins at the height of the best breeding season on record for this vulnerable species.[48] The oiled birds were brought to an abandoned train repair warehouse in Cape Town to be cared for. An additional 19,500 un-oiled penguins were removed from Dassen Island and other areas before they became oiled, and were released about 800 kilometres east of Cape Town, near Port Elizabeth. This gave workers enough time to clean up the oiled waters and shores before the birds could complete their long swim home (which took the penguins between one and three weeks). Some of the penguins were named and radio-tracked as they swam back to their breeding grounds. Tens of thousands of volunteers helped with the rescue and rehabilitation process, which was overseen by the International Fund for Animal Welfare (IFAW) and the South African Foundation for the Conservation of Coastal Birds (SANCCOB), and took more than three months to complete. This was the largest animal rescue event in history; more than 91% of the penguins were successfully rehabilitated and released – an amazing feat that could not have been accomplished without such a tremendous international response.[49]

Due to the positive outcome of African penguins being raised in captivity after tragedies such as the Treasure oil spill, the species is considered a good "candidate for a captive-breeding programme which aims to release offspring into the wild"; however, worry about the spread of new strains of avian malaria is a major concern in the situation.[50]

Bringing the birds inland led to the exposure of penguins to parasites and vector species such as mosquitoes, including mosquitoes carrying avian malaria, which has caused 27% of the rehabilitated penguin deaths annually.[51]

Small scale oil spills (of less than 400 litres (110 US gal)) have occurred at the Port of Ngqura since bunkering activities started there in 2016. Bunkering is a ship refueling process that can result in oil spills and oil slicks entering the water. Hundreds of African penguins have been harmed following these spills,[52] due to the port's close proximity to penguin rookeries on St. Croix Island and seabird habitat on neighbouring Jahleel and Brenton Islands.

Commercial fisheries of sardines and anchovy, the two main prey species of the penguins, have forced these penguins to search for prey farther offshore, as well as having to switch to eating less nutritious prey.[13] Restricting commercial fishing in the immediate vicinity of colony sites such as Robben Island for short periods (3 years) was shown to markedly improve penguin breeding success. Longer closure periods and closures near other colonies are being evaluated.[53][54][55]

The African penguin is one of the species to which the African-Eurasian Waterbird Agreement (AEWA) applies. In September 2010, it was listed as endangered under the US Endangered Species Act.[13] As of 2018, the African penguin is listed as endangered on the IUCN Red List. Its population is approximately 50,000 birds and declining.[56]

Many organisations such as SANCCOB, Dyer Island Conservation Trust, SAMREC and Raggy Charters with the Penguin Research Fund in Port Elizabeth are working to halt the decline of the African penguin. Measures include monitoring population trends, hand-rearing and releasing abandoned chicks, establishing artificial nests and proclaiming marine reserves in which fishing is prohibited.[1] Some colonies (such as on Dyer Island) are suspected to be under heavy pressure from predation by Cape fur seals and may benefit from the culling of individual problem animals,[54][57] which has been found effective (although requiring a large amount of management effort) in trials.[58]

Established in 1968, SANCCOB is currently the only organisation mandated by the South African government to respond to crises involving seabirds along South Africa's coastline and is internationally recognised for the role it played during the MV Treasure oil spill. A modeling exercise conducted in 2003 by the University of Cape Town's FitzPatrick Institute of African Ornithology found that rehabilitating oiled African penguins has resulted in the current population being 19 percent larger than it would have been in the absence of SANCCOB's rehabilitation efforts.[59]

In February 2015, the Dyer Island Conservation Trust opened the African Penguin and Seabird Sanctuary (APSS) in Gansbaai, South Africa.[60] The centre was opened by then-Department of Tourism minister Derek Hanekom,[61] and will serve as a hub for seabird research carried out by the Dyer Island Conservation Trust. The centre will also run local education projects, host international marine volunteers, and seek to improve seabird handling techniques and rehabilitation protocols.