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Penguin mother and chicks P. Dee Boersma penguinstudies. Penguin chicks have a high mortality rate. In some places they starve or are eaten by seabirds and small mammals. They can also freeze to death, a risk for the Antarctic species. One parent goes out to sea to feed while the other stays at the nest with the chick. Parents feed their chicks by regurgitating partially digested food.
This involves losing the downy feathers they hatch with and growing a full coat of water-tight feathers. Fledging usually occurs after two to four months. Adult penguins molt their feathers after the breeding season ends and chicks have fledged.
All birds lose feathers and grow new ones, but penguins have adapted to molt and regrow all their feathers at once. Penguins go on a feeding binge to bulk up before molting. Because their feathers are not water-tight during the molt, they stay onshore and fast during the two to five weeks it takes for new feathers to grow in.
During this period penguins are particularly vulnerable to predators on land. Depending on the region, penguins are hunted by foxes, leopards, and other small mammals as well as other seabirds, like gulls. Once the molt is completed, penguins are able to return to the sea and begin their travels in search of food.
When they are at sea following the food supply, Magellanic Penguins migrate along the coasts of Argentina and Chile, reaching as far north as Peru on the Pacific side and Brazil on the Atlantic side.
Penguins spend most of their lives out at sea searching for their favorite foods, including fish, squid, and krill. Chronic oil pollution and mortality still occurs off Brazil, Uruguay, northern Argentina and Chile Garcia-Borboroglu et al.
Future petroleum extraction is under consideration offshore of the Falkland Islands Malvinas , Patagonia and Uruguay, which would likely increase mortality.
Southern colonies are subject to disproportionately high mercury levels for their trophic level Brasso et al. Birds from the northern colony in Punta Tombo colony have been found to have much lower mercury levels Frias et al. Detrimental effects were not evident in that study, but mercury exposure could be a long-term or synergetic threat. This species interacts with fisheries along the coast of South America, through bycatch mortality from gillnets, trawls and purse-seines Gandini et al.
Tamini pers. Population trends in response to these threats have not been quantified. Fisheries may also reduce prey for penguins; the hake fishery in Argentina for example collapsed due to overfishing during the s Alemany et al.
A potential expansion of the Argentinian anchovy fishery might impact breeding penguins Skewgar et al. Fisheries in northern Argentine Patagonia may be having an additional effect, as bycatch includes anchovy and juvenile hake, which are an important part of the species's diet Frere et al.
Climate change has been reported to have an impact, as precipitation has increased over the last 30 years and young chicks that get wet often die from hypothermia Boersma and Rebstock Precipitation causes nest burrows to collapse Boersma , Boersma and Rebstock Decreasing breeding synchrony interacted with climate change to increase the part of the season when chicks are vulnerable to wetting Boersma and Rebstock High temperatures in the breeding colonies can kill adults and chicks Boersma and Rebstock , P.
Boersma unpublished data. Changing patterns of precipitation and atmospheric and oceanic circulation are likely to affect winter conditions in the Atlantic, indirectly affecting breeding, as the extent of the Rio de la Plata plume affects females' colony arrival timing and body condition Rebstock and Boersma Indirect effects of climate change through changes in prey populations or availability are completely unknown.
In some areas of Chile, eggs and adults are collected for human consumption and adults are taken for bait Boersma et al. Egg-collection occurred also in the Falklands Islands Malvinas. The introduction of feral dogs and other invasive species in the breeding colonies have resulted in local extirpations Suazo et al. Magellanic Penguins stay together in flocks as they hunt for food.
They join larger colonies on land when breeding season arrives. Female Magellanic Penguins mature sexually around 4 years of age, males around 5 years. Magellanic Penguins gather in huge nesting colonies during the breeding season along the coasts of the Falkland Islands, the south end of Chile, and Argentina. These colonies can number as high as , individuals.
The Magellanic Penguins are monogamous, returning to the same mating partner every year. The female is able to find her mate through his call. The Penguins begin arriving and mating in September, the egg laying begins in October. Two eggs are usually laid. The incubation of the eggs lasts around 40 days, the parents swapping off the incubation shift every week and a half or so. Once the chicks hatch both parents take turns taking care of it, again swapping off so one can go hunt and bring back food to the nest every 2 or 3 days.
This process takes a full month. By the end of the first month after hatching the chicks will have begun to grow their waterproof feathers. The chicks graduate to fledglings adolescent Penguins with grown-in feathers anywhere from 2 to 16 months after hatching, depending heavily on how much food is available in the area.
There are estimated to be about 1.
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