Humboldt penguin (Spheniscus humboldti)
Also known as: Peruvian penguin
Genus Spheniscus (1)
Size Length: 65 cm (2)
Average weight: 4 kg (3)
Classified as Vulnerable (VU B2abcde+3bc, C1) on the IUCN Red List 2003 (1). Listed on Appendix I of CITES (4) and on Appendix I of the Convention on Migratory Species (CMS or Bonn Convention) (5).
Humboldt penguins, named after the cold current of water running from the Antarctic to the equator along the west coast of South America (itself named after the German naturalist Friedrich Humboldt), are a medium-sized penguin. They have proportionately large heads, black backs and tails, and a black band across the chest that runs down the body beneath the flippers to the black feet. The face is also black, but separated from the head and neck by a white border. The strong bill is black with a white band near the tip and the lower mandible has a pink fleshy-coloured base extending to the front of the eyes (6). Females are slightly smaller that the males but are otherwise similar. Juvenile birds are predominantly slate grey across the head and back, white at the front, and lack the bold double stripe of the adults (6).
This species is found along the coasts of Peru and Chile within the reaches of the Humboldt Current. Some birds have been recorded as vagrants northwards off Columbia There are also isolated colonies further to the south on the Punihuil Islands
Humboldt penguins nest on rocky coasts and islands with suitable terrain for constructing nest burrows (2).
These penguins can be found in their breeding colonies throughout the year although the main breeding seasons are from March to April and September to October, depending on the location. The birds dig burrows into the sand or guano cliffs, or find small crevices in which to lay the eggs. Two eggs are laid over a period of 2-4 days, incubation taking between 40 and 42 days, with both adult birds sharing nest duties. The chicks usually hatch two days apart and are fed by both adults once they have acquired their first thick downy coats (3).
Chicks rarely leave their nest scrape until they are fledged at about 12 weeks. They then fend for themselves along the coast for several months before returning to establish their own nests, often within the same colony where they were reared. They reach maturity at the age of two years (3).
Humboldt penguins exploit the cold waters off the South American west coast for food. The Humboldt Current flows northwards from Antarctica, and provides a rich harvest of fish, particularly anchovies, but the birds also feed on other fish species, krill and squid. Although they can reach depths of 150 metres, the birds rarely descend deeper than 60 metres (3).
These penguins have been popular exhibits in zoos for many years and have been known to live for up to 30 years in captivity. They rarely reach this age in the wild (3).
The principal risks to Humboldt penguins come from human over-harvesting of the fish stocks, especially anchovies, and exploiting the birds' guano beds, the mineral-rich guano being used as fertiliser. Removal of the guano deprives the birds from constructing nest burrows and leaves the eggs and chicks vulnerable to weather and predators (3).
On the mainland nesting sites, wild dogs take eggs, chicks and even adult birds. Natural predators on land include foxes and caracaras (a large native hawk), whilst in the water the penguins fall prey to fur seals, sharks and whales. A more alarming trend over recent decades has been the effects of El Niño-related events. This is known to affect penguin numbers in two ways; by displacing the Humboldt Current with warmer, less food-rich water, and raising severe storms that can wash out the nesting colonies (3). There are also cases of birds being drowned in fishing nests and they are constantly at risk from marine pollution (3).
Following a series of disastrous breeding years, which included two El Niño Southern Oscillation (ENSO) events, a population and habitat viability survey was carried out in 1998 on the Humboldt penguin. This concluded that, using figures for current breeding trends and estimating a world population of between 3,300 and 12,000 breeding pairs, the species was likely to become extinct within the next century (2). Legislation to assist the recovery of the Humboldt penguin has been passed in Chile, including a 30 year moratorium on killing or capturing the birds, and protection of the four principal breeding colonies. In Peru, the major colonies are also protected and the extraction of guano is managed by government (2).
Further proposed conservation targets to save this species include the creation of marine nature reserves around the main breeding grounds, greater care over the extraction of guano, reducing the fish harvests during ENSO events and setting up ‘awareness' programmes to limit the hunting of penguins and accidental entanglement (by-catch) in fishing nets (2).
International Penguin Conservation:
1. IUCN Red List (April, 2004)
2. Capper, D.R. and Statterfield, A.J. (2000) Threatened birds of the world. Lynx Edicions, Barcelona and Birdlife International, Cambridge.
3. International Penguin Conservation (April, 2004)
4. CITES (April, 2004)
5. Convention on Migratory Species (April, 2004)
6. Soper, T. and Sparks, J. (1968) Penguins. David and Charles, Newton Abbott
Information and images courtesy of ARKive@