Bird Families

Scientists have told why penguins are threatened with extinction

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Study history

The Magellanic penguin, or the Magellanic penguin (Latin Spheniscus magellanicus) is a species of the penguin genus of spectacled penguins. The species is named after Fernand Magellan, who discovered penguin habitats.

Spread

The main nesting area is the Patagonian coast, Tierra del Fuego, the islands of Juan Fernandez and the Falklands. Individuals have been sighted as far north as Rio de Janeiro and southern Peru. also inhabits the shores of South America north of Coquimbo (Chile) and Rio de Janeiro.

Appearance

Adults reach a height of 70-80 cm and a weight of 5-6 kg. The back (upper) part of the penguins is black, the front part is white, with two or one black stripes on the neck. The beak and paws are of a dirty gray color, with a red or orange tint.

Reproduction

Females can start breeding at the age of 4 years, and males usually a year later. Adults arrive at nesting sites in September and, after digging holes or repairing old holes, start laying eggs somewhere in mid-October. If Magellanic penguins lose their clutch, then they do not postpone a second one. The clutch contains two eggs of the same size, weighing about 125 g, the second of which is laid 4 days after the first. Incubation lasts about 40 days, and the female incubates the clutch first, while the male feeds in the sea. It feeds at a distance of up to 500 km from the colony and returns after 15-20 days to change the female. Then she leaves to feed for the same period. Birds usually feed at depths less than 50 m, but they can dive up to 100 m. Magellanic penguins consume approximately equal amounts of fish, molluscs and crustaceans. Both parents heat chicks in shifts until they are about one month old.

By the end of the first month of life, the chicks develop a mesoptile downy outfit, and the chicks already dare to wander outside the burrow. While in the burrow, the penguins are protected from both predators and bad weather. However, heavy rains can flood burrows and although chicks rarely drown in them, this is very dangerous for them. The penguins get wet and die from hypothermia, as the wet mesoptile loses its excellent heat-insulating properties. Parents, feeding chicks, give preference to the first hatched, which often leads to the death of the second chick. When feeding conditions are favorable, both chicks grow up successfully. Depending on the abundance of food, the rally occurs at the age of 9-17 weeks. The cages are similar to adult birds, but their plumage is more gray. The weight of juveniles in the mainland colonies is 3.3 kg, while in the Falkland ones - only 2.7 kg. Chicks that left the colony weighing less than 3.0 kg practically do not survive. Breeding success is usually in the range of 1.0-1.6 chicks per pair in mainland colonies and only 0.5 in the Falklands. In the latter case, juvenile survival is very low, resulting in a 80% decline in bird numbers with the start of commercial fishing in the area.

Lifestyle

Life expectancy is about 15 years, less often - up to 20 years, in captivity it is possible to live up to 20-25 years. Nests are arranged in holes that are dug in soft soil.

In Chile and Argentina, in order to get food for chicks, adult birds spend 16-18 hours, while in the Falklands, the same amount of food is obtained in 35 hours. During feeding, Magellanic penguins feed mainly within 30 km of their nesting sites, except for birds from the Falkland Islands, where birds are forced to feed further due to conflict with commercial fishing.

After the chicks have left the colony, the parents go to sea to fatten before the annual moult starting in March. Molting lasts 3-4 weeks, after which the birds leave their nesting sites and remain in the sea until the next breeding season begins. During wintering, birds migrate widely, reaching the Brazilian coast up to 10-15 ° S latitude.Magellanic penguins can live up to 20 years. The natural predators of Magellanic penguins in the sea are sea lions, leopard seals and killer whales, while birds of prey - gulls and skuas - threaten chicks and eggs.

Food

Magellanic penguins feed on krill, cuttlefish and small fish.

Number

The world population is 1.8 million pairs, of which 100,000 nest in the Falklands, 900,000 in Argentina and 800,000 in Chile.

Magellanic penguin and man

The colonies on the islands of Magdalena and Martha in the Strait of Magellan have long been subject to raids by Indians, who caught a small number of birds, but the number of the species remained stable. In the 18th-19th centuries, the penguins began to be attacked by the Europeans, who organized numerous expeditions here. On the island of Magdalena alone, Europeans harvested up to 14 thousand birds a year. The number of the species began to decline. And despite the fact that today a national park of penguins has been created on the islands of Magdalena and Marta, the number of this species remains small. Firstly, the collection of eggs by the local population continues, and secondly, numerous tourists often disturb the birds and destroy their burrows.

Extinction reasons and protection

The colonies on the islands of Magdalena and Martha in the Strait of Magellan have long been subject to raids by Indians, who caught a small number of birds, but the number of the species remained stable. In the 18th-19th centuries, the penguins began to be attacked by the Europeans, who organized numerous expeditions here. On the island of Magdalena alone, Europeans harvested up to 14 thousand birds a year. The number of the species began to decline. And despite the fact that today a national park of penguins has been created on the islands of Magdalena and Marta, the number of this species remains small. Firstly, the collection of eggs by the local population continues, and secondly, numerous tourists often disturb the birds and destroy their burrows.

Gallery

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Magellanic Penguin in Patagonia, Chile

Falkland Islands Magellanic Penguins 01.jpg

A pair of Magellanic penguins in the Falklands

135 - Cap Virgenes - Manchot de Magellan - Janvier 2010.JPG

Magellanic penguin family in Patagonia

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Magellanic Penguin Colony in Patagonia

Aggressive Magellanic penguins turned out to be "left-handed"


Ronald Woan / flickr
The most aggressive Magellanic penguins (Spheniscus magellanicus

) in a fight with relatives, they attack the right side of their head with their beak - this means that they use their left eye to plan the battle. This was found by scientists from the United States, Brazil and Argentina, who studied the laterality of the fins and paws of a small population of 300 penguins living on the territory of one of the Argentine peninsulas. She was unable to obtain data on another possible preference for one part of the body over the lateral one, according to an article published in the journal
PeerJ
.

Anatomical, functional, or physiological dominance of one half of the body over the other is often associated with the laterality of some parts of the brain. For example, among people, the speech divisions are located mainly on the left in right-handers, and in left-handers - bilaterally, that is, on the right and left sides, and in cichlid fish, the skew of the jaw to the right and left depends on how anatomically developed the right and the left side of the department responsible for processing visual information.

At the same time, in some species, the laterality of body parts and sensory organs can affect survival - for example, in pheasants, "left-handers" and "right-handers" are less survivable than relatives that do not have a dominant paw. Scientists led by Thaís Stor from the Federal University of Pernambuco (Brazil) decided to check the presence of laterality in Magellanic penguins. To do this, they studied a small (about 300 individuals) group of penguins on the Argentine peninsula of Punta Tombo (this island is home to the world's largest population of Magellanic penguins).

Penguin paws and fins were checked for laterality.To do this, the researchers put an obstacle in the middle of their habitat in the form of a small platform, which the penguins had to cross. Scientists estimate that 53 percent of penguins climbed the obstacle with their right paw and 47 percent with their left paw, suggesting that there is no preferred paw in the population. At the same time, it is necessary to clarify that each penguin was observed only once; therefore, it is also impossible to say that birds have an individual preference expressed in functional laterality. The scientists also found that penguins are more likely to (p

Magellanic penguins overcome obstacles

Thaís Stor et al. / PeerJ, 2019

Magellanic penguin stretched out its leg to keep it warm

Thaís Stor et al. / PeerJ, 2019

As for the fins, scientists were able to detect anatomical laterality in penguins: having studied 76 skeletons of Magellanic penguins, they found that the keel (the outgrowth of the sternum, to which the pectoral muscles are attached) in 60.5 percent of cases was slightly oblique to the right or left side, and 11 percent of the penguins studied had more feathers on one of their fins. At the same time, the lobes of the right and left anatomical laterality were approximately equal, which indicates that the presence of laterality is not population-based.

Keel specimens of Magellanic penguins

Thaís Stor et al. / PeerJ, 2019

Feathers on the right and left fins

Thaís Stor et al. / PeerJ, 2019

Finally, scientists have studied the behavior and preferred strategy of the penguins in fights. They found that fighting penguins were twice as likely to have blood and wounds on the right side as opposed to the left, suggesting that the attacking opponent was most likely planning an attack from their own left side. At the same time, there was always more blood on the right side of the head of wounded penguins: from this, scientists concluded that penguins who use their left eye for planning in a fight and, accordingly, attack the right side of the enemy's head are more aggressive.

The authors of the work, thus, came to the conclusion that there is no anatomical and physiological laterality of fins and paws in Magellanic penguins - at least not at the population level. At the same time, laterality is most likely present when choosing a strategy in social behavior, namely, in a fight. The fact that more aggressive birds used the left eye to plan a fight, according to scientists, correlates with the data that the right side of the brain is responsible for initiating aggressive defensive behavior, and the left side is responsible for inhibition (the organs of vision are contralaterally related to the brain).

The laterality of the sense organs is not as pronounced as the laterality of the limbs. In ants, however, it can be traced both at the anatomical and functional levels: from the number of ommatidia in the eyes of ants of the species Temnothorax albipennis

depends on whether they are folded in the maze to the right or to the left.

Elizaveta Ivtushok

Excerpt from Magellanic Penguin

“Bonjour, ma cousine,” said Pierre. - Vous ne me gesonnaissez pas? [Hello cousin. Don't you recognize me?] - I know you too well, too well. - How is the count's health? Can I see him? - asked Pierre awkwardly, as always, but not embarrassed. - The count suffers both physically and mentally, and it seems that you took care to inflict more moral suffering on him. - May I see the Count? - Pierre repeated. - Hm. If you want to kill him, kill him completely, you can see. Olga, go and see if the broth is ready for your uncle, the time is soon, '' she added, showing Pierre that they were busy and busy calming his father down, while he was obviously busy only with upsetting. Olga left. Pierre stood for a while, looked at the sisters and, bowing, said: - So I will go to my room. When it will be possible, you tell me. He went out, and the ringing, but quiet laugh of his sister with a mole was heard behind him. The next day, Prince Vasily arrived and settled in the count's house.He called Pierre to him and said to him: - Mon cher, si vous vous conduisez ici, comme a Petersbourg, vous finirez tres mal, c’est tout ce que je vous dis. [My dear, if you behave here as in Petersburg, you will end very badly, I have nothing more to say to you.] The count is very, very sick: you do not need to see him at all. Since then, Pierre was not disturbed, and he spent the whole day alone upstairs, in his room. While Boris entered to him, Pierre walked around his room, occasionally stopping in corners, making threatening gestures to the wall, as if piercing an invisible enemy with a sword, and sternly looking over his glasses and then starting his walk again, pronouncing vague words, shaking shoulders and spreading his arms. - L'Angleterre a vecu, [England is over,] - he said, frowning and pointing his finger at someone. - M. Pitt comme traitre a la nation et au droit des gens est condamiene a ... [Pitt, as a traitor to the nation and popular law, is sentenced to ...] - He did not manage to finish the sentence to Pitt, imagining himself at this moment by Napoleon himself and together with having already made the dangerous journey across the Pas de Calais and conquered London as his hero, when he saw a young, slender and handsome officer entering him. He stopped. Pierre left Boris as a fourteen-year-old boy and decidedly did not remember him, but despite the fact, with his characteristic swift and cordial manner, he took his hand and smiled amiably. - You remember me? - Boris said calmly, with a pleasant smile. “My mother and I have come to the count, but it seems he is not quite well. - Yes, it seems unwell. Everything worries him, - answered Pierre, trying to remember who this young man is. Boris felt that Pierre did not recognize him, but did not consider it necessary to identify himself and, without feeling the slightest embarrassment, looked him straight in the eyes. “Count Rostov asked you to come and dine with him today,” he said after a rather long and awkward silence for Pierre. - AND! Count Rostov! - said Pierre happily. - So you are his son, Ilya. I, you can imagine, did not recognize you in the first minute. Remember how we went to Sparrow Hills with m me Jacquot ... [Madame Jaco ...] a long time ago. “You are mistaken,” Boris said slowly, with a bold and somewhat mocking smile. - I am Boris, the son of Princess Anna Mikhailovna Drubetskaya. Rostov's father's name is Ilya, and his son's is Nikolai. And I didn't know any m me Jacquot.

Dramatic extinction of king penguins deemed unexplained

The largest colony of king penguins in the world, located on Cauchon Island in the Crozet Archipelago in the subantarctic region, is rapidly declining.

In the 1980s, the population numbered about two million, including 500,000 breeding pairs. Now only 60,000 birds are ready to breed.

Researchers at the Shize Center for Biological Research (CNRS) compared images taken in 1982 and 1988 with satellite images from 2005 to understand how the colony's life has changed. It turned out that over the past 35 years, the population has decreased by 88% - this is a third of the total number of all king penguins, reports Antarctic Science.

But, surprisingly, a similar situation is observed only on Cauchon Island. The penguin colony on Posession Island has remained stable since the 1960s, and groups on Marion Island and the Kerguelen Archipelago have even increased.

Scientists have come to the conclusion that there is some local reason for the extinction of penguins, but which one is still a mystery.

Experts have put forward several theories. One of them is the fluctuations in the temperatures of the surface layer of the Indian Ocean, noted in 1997. The phenomenon could undermine the food base of the penguins and provoke a partial extinction, but one colony after that successfully recovered, and the other takes longer.

The second theory is resettlement. Satellite images have shown that a small group of birds has settled away from the main population, forming a new colony. But it is too few in number to explain all the losses.

Scientists noted that other species of animals also live on Cauchon Island - wild cats and mice.It is possible that they could infect the penguins with parasites or serious diseases.

There is already a known case when ticks literally attacked penguins - this happened in the 1990s on Marion Island. But this did not affect such a large part of the population, and the number of birds after the epidemic quickly recovered.

Natural disaster is also unlikely. Researchers have found no evidence that the island was hit by a tsunami or volcanic activity.

Note that the last scientific expedition left Cauchon Island in 1982. Since then, all information about him came only from satellite images. Scientists note that the best way to unravel the mystery of the colony's extinction is to go to the scene and personally study all the factors. Apparently, the decline in numbers began about 20 years ago and continues to this day. If you do not take action, the island could become empty in the next decade.

Earlier it was reported that a penguin population of about 1.5 million was accidentally discovered in Antarctica. They live on Danger Island.

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