COASTAL BIRDS PENGUINS There Are 18 Species of Penguins in the World and All of Them Are Found in the Southern Hemisphere
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COASTAL BIRDS PENGUINS There are 18 species of penguins in the world and all of them are found in the Southern Hemisphere. The penguins of our region travel on land by walking or hopping. They swim with great speed and agility. The flippers—wings—are their sole means of propulsion in the water; the feet are trailed behind or used in steering. Some species progress by ‘porpoising’, which involves swimming underwater for some distance, then emerging in a graceful arc to take a fresh breath, and submerging again. Penguins do not have normal feathers, as do most birds, but are covered almost uniformly with small, scale-like feathers. Penguins moult all of their feathers and, in some species, even shed the shields from the beak within a short space of time. A moulting penguin has a dishevelled appearance; losing its feathers in huge patches as new feathers appears. During the moulting period, which may last several weeks, the penguin does not enter the water to feed. Feeding Penguins eat crustaceans, small fish and cephalopods. Their food is taken by pursuit diving even to depths of 100m. They appear to stun their prey first from below with a blow from their beak before swallowing it beneath the surface. Social behaviour Penguins have a number of social behaviours from head swaying, trumpeting, quivering, mutual preening, stone carrying, aggressive behaviour, submissive and appeasing behaviours. They also appear to find that fishing in groups is advantageous. Bonding and breeding The greatest concentrations of penguins are seen in rookeries, where the birds gather to breed. Some penguin pair’s bonds are maintained in successive seasons, but frequent changes in pairs have been noted even if both members are alive and present in a colony. Penguins vary in their nesting methods such as a scrape in the ground lined with pebbles, burrows or in small crevices caused by plant roots or rocks. They usually lay two eggs and normally only one chick survives. Roughly about 65% of all eggs laid do hatch and most of the chicks survive, as the parents are good guarders. In general, both sexes incubate the eggs and feed the young. Most penguin chicks are covered with a sooty-grey down at hatching, although some have a pattern of soft greys and whites. Chicks of certain species remain confined to the burrow or nest throughout the entire nesting period, during which time their parents feed them. On their parents' return from fishing, parents and chicks recognize each other in a group often numbering thousands. In some cases there ensues a feeding chase in which the chick leaves the nursery to chase one of its food-laden parents. The parent finally stops and regurgitates partly digested food for the chick. After a young penguin has shed the last of its down and acquires its first plumage, it enters the sea to fend for itself. AFRICAN BLACKFOOTED PENGUIN (Spheniscus demersus) ENDANGERED This penguin is the only species that breeds in Africa mainly off southern Africa. They are also endemic to this region. They were previously known as the Jackass penguin but are now formally known as the African Blackfooted Penguin. These penguins are now (June 2010) listed as an endangered species due to many factors. Up until 1967 collecting penguin eggs (approx. 13 million) reduced their numbers dramatically and that, coupled with smaller pilchard shoals, probably had the most major impact. Historically African Blackfooted penguins nested in their guano deposits. This changed when the fertiliser industry of the 1800’s boomed and guano deposits were scraped from their breeding grounds. This practice is now illegal but the damage has certainly been done as natural nesting sites have been lost. In recent times heavy oil spills along the west coast of South Africa, despite large-scale penguin capture and cleanup programmes, has resulted in further reduction in their numbers. During the Treasure oil spill (June 2000) almost 19,000 birds were collected for rehabilitation. Other reasons responsible for their decline are climate variation; shift in location of prey (W>E); fisheries interactions (competition & entanglement); coastal and inshore mining; disease; human disturbance. Due to the increased tourist interest and new protected breeding areas being designated along the coast (Boulders and Robben Island for example) efforts are being made to ensure their survival. The situation for this species, however, remains dire. In 1910 there were an estimated 1.5 million birds and, at last count, less than 60 000 birds remain. Between the years 2005-2010 the African Blackfooted penguin population halved. FACTS OF INTEREST FOR AFRICAN BLACK FOOTED PENGUINS (ABFP) 1. Camouflage – black on their backs so as to blend in with the depths of the ocean floor. White on their bellies to blend in with the sun shining down from above. 2. ABFP are monogamous, they pick a partner for life. 3. Lay 2 eggs a few days apart and incubation is between 38 & 42 days with both parents being involved. Chicks hatch weight is around 72g. 4. The chicks fledge anywhere between 55-130 days. 5. Eggs hatch a few days apart and the first hatched will generally always be the stronger of the two. In the wild the weaker one will often die. (At Two Oceans Aquarium We weigh our chicks regularly to ensure that they are gaining approximately 10% of their body weight daily. In this way we know that the parents are doing a good job of looking after their offspring.) 6. Every bird moults (replaces all of their feathers) every year and grows a brand new black and white “suite”. During the moult, which lasts about 3 weeks, they remain on land as they are not waterproofed and cannot go to sea to feed. For this reason they gorge on fish just before the moult period and can sometimes double their body weight. This ensures they have enough reserves to keep them healthy until they are newly feathered and can once again venture to sea. 7. They swallow their fish whole with the aid of hook-like protrusions on their tongues and down the back of their throats. As they swallow these hook into the fish and help it down 8. Penguins drink salt water and they are able to desalinate it in order to get their fresh water requirements. This is done thru their nostrils and all sea birds are adapted this way. 9. Penguins have a very high metabolism and can eat many fish in a day. Generally they will eat 1- 4, however in preparation for a moult they will gorge themselves and can eat anything up to 15 or more fish in a day. In the wild the birds remain on land for the moult period of about 3 weeks and they have to have built up enough fat reserves to see them thru this period of not eating. 10. Their appetite increases dramatically during the rearing of offspring too. 11. They can swim at speeds of 30km/hr at very short bursts when hunting. 12. In South African regions they feed on sardines & anchovies; and in Namibian regions on goby, mackerel. 13. They have been known to reach depths of up to 130m but generally hunt at depths less than 80m with up to 20m being most common. They forage within 30-35kms of their breeding colonies. 14. In the wild eggs are laid Feb-Aug; chicks hatch April-Oct; moulting occurs Nov-Feb 15. Predators of the ABFP are: humans, ferel cats, gennets, seals, jackals, mongoose, dogs ROCKHOPPER PENGUINS (Eudyptes chrysocome) These are Antarctic or sub-Antarctic penguins and although they are not endangered at present could easily become so. There is increasing pressure on the their land habitats for human access (eco-tourism) and other human activities whilst large fishing fleets now in those waters pose a threat as well. The mature Rockhoppers have short stubby red bills and pale yellow stripes in front of the eyes forming a long drooping and laterally projecting crests behind the eye. Immatures have shorter crest and smaller brown beaks. Males are generally heavier than the female and the average weight is 2.8 to 3 kilograms for males and 2.3 to 2.7 kgs for a female. On land they can hop remarkably quickly with their feet together. Distribution of these penguins is mainly the sub-Antarctic regions and in summer they breed on about 16 islands including Marion and Prince Edward islands. Occasionally moulting juveniles are found on South African beaches between January and February. Predators Eggs, chicks and sickly penguins are often taken from the land nests by skuas, northern giant petrels or Norway rats. At sea, however seals hunt the adults. AFRICAN BLACK oystercatcher (Haematopus moquini) The oystercatcher's origins can be traced on the evolutionary scale to approximately 60-80 million years ago. They originated in the Southern Hemisphere and today they exist mostly in the southern Hemisphere with 10 species in existence. Avocets and stilts are the oystercatcher's closest relatives. Various species of oystercatcher are found in New Zealand; South America and North America. In South Africa one species of oystercatcher exists. Food options are limited because they live on a narrow tract of land. They specifically choose limpets as well as mussels. Limpets are nocturnal animals and move around a lot ...this is when the oystercatcher does most of its feeding. The oystercatcher is equipped with a dextrous and very strong beak. The oystercatcher is territorial and will defend its territory from other oystercatchers. They are faithful to their mates and can live 20-40 years. Nests are not very obvious and often found in open ground.