Brazilian merganser facts for kids
Quick facts for kids Brazilian merganser |
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| Conservation status | |
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| Genus: |
Mergus
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| Species: |
octosetaceus
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The Brazilian merganser (Mergus octosetaceus) is a special type of diving duck found in South America. It belongs to a group of birds called Mergus.
This duck is one of the most endangered waterfowl in the world. There might be fewer than 250 of them left in the wild. A small number also live in zoos or special centers in Brazil. This duck has a long, sharp beak with many tooth-like edges.
Contents
What Does the Brazilian Merganser Look Like?
This merganser is a slim, dark duck. It has a shiny dark-green head with a long feathery crest. Females usually have a shorter, more worn-looking crest. Their upper body is dark grey. The chest is light grey, becoming lighter towards a whitish belly.
When they fly, you can see a white patch on their wings called a speculum. They have a long, thin, jagged black bill. Their feet and legs are red. Females are smaller than males. They also have a shorter bill and crest. But both sexes look the same in color. These slim ducks are about 49 to 56 centimeters (19 to 22 inches) long when they are adults. Young Brazilian mergansers are mostly black. They have a white throat and chest.
Sounds of the Brazilian Merganser
Brazilian mergansers are usually quiet birds. But they can make barking calls when needed. Four different calls have been heard. A harsh krack-krack sound is an alarm call they make when flying. Males make a barking, dog-like call. Females make a harsh rrr-rrrr sound. Their contact call, used to talk to each other, is a soft rak-rak-rak. Baby ducks, called ducklings, make a high-pitched ik-ik-ik sound.
Where Do They Live and Nest?
Brazilian merganser pairs live in their own special areas. These areas are along 8 to 14 kilometers (5 to 9 miles) of rivers. They need good places to nest and find food. They build their nests in tree holes or cracks in rocks. Sometimes they use old burrows made by armadillos.
It is thought they breed during the southern winter. This is when there is less rain and water levels are low. But this might change depending on the area. The female usually lays three to six eggs in June and July. The chicks hatch in July and August. The young birds can fly by September or October. Only the female sits on the eggs to keep them warm. But both parents take care of the young. This is very unusual for ducks! Both parents even help feed the young birds directly.
Adult Brazilian mergansers are believed to stay in the same area all year. We don't know much about their movements. So, this information is still being studied.
What Do They Eat?
Fish is the main food for the Brazilian merganser. They also eat molluscs, insects, and their larvae. These birds usually hunt in pairs. They catch fish by diving in river rapids and calmer backwater areas.
Where Do Brazilian Mergansers Live?
The total number of these mergansers is thought to be less than 250 birds. Originally, these ducks lived in central-south Brazil. They also lived in nearby parts of Paraguay and Argentina. Today, most confirmed groups are in Brazil. A newer group has been found in Argentina. We don't have much information about most of these groups.
The most important and well-known group is in the Serra da Canastra region of Brazil. Other groups are hundreds of kilometers away. In 2006, there were 47 mergansers in Serra de Canastra. This included 28 adults and 19 young birds. Most mergansers are found in the Serra da Canastra National Park. About 70 birds have been seen near the park's main office in the São Francisco river area. In the Jalapão region, about 13 birds were estimated in the Novo river in 2009/2010. This included four pairs and some single adults.
In 2002, the species was also found in the Arroyo Uruzu in Misiones, Argentina. This was the first time they were seen there in ten years. Researchers had looked for them a lot before this. The bird was last reported in Paraguay in 1984. Very little of their natural home is left there. However, some local reports say a few might still be living in the area.
What Kind of Home Do They Need?
These slim Brazilian mergansers live in small numbers in wild, mountainous areas. They like clean rivers and streams with fast-flowing water and plants along the banks (riparian vegetation). Brazilian mergansers are very protective of their homes. They defend long parts of the river and the land around the fast water.
They are known to stay in the same rivers. They do not move or want to move even if their homes disappear. These birds need large areas to live. Sadly, their natural home is shrinking fast.
Why Are Brazilian Mergansers in Danger?
Brazilian mergansers are very sensitive to changes in their home. These changes are mostly caused by people. A big danger to their survival is rivers getting filled with dirt. This is called silting. It happens because of more farming, mining, and soil erosion. Deforestation, which is cutting down forests, also causes this.
Farming and Forest Fires
Old ways of managing land for farming can harm natural resources. This is especially true for water, which both the mergansers and farmers need. One farming method used here is shifting cultivation. This means farmers burn forest areas to clear land. This damages the plants, soil, and the animals living there.
Dams and Hydroelectric Plants
A new danger to the species is the building of hydroelectric power plants. These plants are planned for the same rivers where Brazilian mergansers live. This includes rivers in Paraná, Goiás, and Tocantins states. Hydropower plants are a big threat. They turn clear, flowing rivers and streams into cloudy lake systems. This project has government support, even with the harm it might cause.
Building dams has also caused many of these birds to disappear. The Urugua-i reservoir was filled between 1989 and 1991. This greatly affected Brazilian mergansers in Argentina. Their numbers dropped a lot when their fast-flowing rivers became large lakes. After the Urugua-i dam was built, the birds have only been seen on the Uruzu stream. This stream flows into the Urugua-i. Dams flood good places for the birds to live. This is especially true in Brazil and Paraguay, where the mergansers build their nests and lay eggs.
Tourism and Other Dangers
Tourism is another threat to the Brazilian merganser. The beautiful Serra de Canastra National Park attracts people from all over. Tourists come to see the clear water and over 150 waterfalls. Sporting activities also bother the Brazilian mergansers. Activities like canoeing and rafting disturb their natural homes in the rapid rivers. This can stop them from breeding. Water pollution and cutting down forests are also worries as new buildings are put up.
Other dangers include inbreeding (when related birds breed), pesticides, and being hunted by other animals (predation). Very few birds survive these threats. It means they could soon become extinct. In the past, hunting the birds for food and collecting them for display also caused their numbers to drop.
See also
In Spanish: Pato serrucho para niños
