Plumbeous ibis facts for kids
Quick facts for kids Plumbeous ibis |
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| Current resident extant range according to the IUCN 2012 |
The plumbeous ibis (Theristicus caerulescens) is a large bird that lives in central South America. It used to be called the blue ibis. This special bird is a type of ibis and is only found in certain areas.
Contents
About the Plumbeous Ibis
What does the plumbeous ibis look like?
This large ibis is about 71–77 cm long. Males have wings that are 397-450mm long, and females have wings that are 360-406mm long. Both male and female ibises look similar, but females are a bit smaller.
You can easily spot a plumbeous ibis by its unique features. It has a shaggy, grey crest of long feathers on the back of its head. This crest can be up to 10 cm long. There's also a clear, thin white band of feathers around its forehead. Because of this, it's sometimes called the "headband ibis" in German.
The plumbeous ibis usually has grey feathers. These can look bluish, greenish, or brownish depending on the light. Its back feathers are mottled grey-brown, making its underside appear lighter. The feathers on its wings and tail are dark brown or black, with a shiny greenish-bronze glow. Some people have described its feathers as silvery grey in the right light.
The ibis has a black bill that curves downwards. The skin around its eyes and throat is black or dark grey. Its legs are pinkish-orange, becoming darker during the breeding season. Its eyes are a deep orange, sometimes a bit lighter near the center.
How do young plumbeous ibises look?
Baby ibises have light grey, fluffy feathers. They don't have the fancy colors of the adults. Young ibises that have learned to fly look different from adults. They have dark eyes, grey legs, and a smaller crest on their neck. Their white forehead band is also bigger and brighter than an adult's.
How does the plumbeous ibis fly?
This ibis is a strong flyer. It stretches out its neck and wings and beats them steadily. It also glides through the air sometimes.
What sounds does the plumbeous ibis make?
The plumbeous ibis makes many loud and different sounds. Its main call is a high-pitched, fast pi-pi-pi-pi. This sound has a metallic ring to it. People have said it sounds like a banjo with brass strings that can be heard far away.
When flying, it makes a slow but strong trumpeting call, like kree kreee kree. It also makes a fast, nasal cackling sound, tututututu, when it's on branches or at its nest. Mates often call to each other from far away. All these loud calls show how important it is for these birds to communicate over long distances.
Where do plumbeous ibises live?
Plumbeous ibis habitat and range
The plumbeous ibis lives in a fairly small area in central South America. You can find it in parts of south-western Brazil, Paraguay, Uruguay, north-eastern Argentina, and northern and eastern Bolivia. There's a group of ibises in northern Bolivia that is separate from the main population.
Even though this bird seems common, it's not found everywhere in its range. It might be very common in some areas, but rare in others. For example, it's common in the Chaco region of Paraguay, especially where there's lots of freshwater.
This ibis mostly lives in lowland grassy wetlands, like the Pantanal. It looks for food in marshes, swamps, shallow lakes, and flooded fields. It also rests in trees near or over the water. You might also see it in higher marshes, up to 600 meters high. These ibises often live near people, in places like dams and rice fields.
Do plumbeous ibises migrate?
Most plumbeous ibises stay in one area all year. However, some have been seen moving short distances. It's thought that these birds might travel between the separate groups to keep the population genetically similar. But scientists don't know if they have regular migration patterns.
How do plumbeous ibises live together?
Unlike many other ibises, the plumbeous ibis does not form large groups with its own kind. You'll usually see them alone or in pairs. Sometimes, you might see small groups of up to six birds. These larger groups seem to be two parents with their young.
Plumbeous Ibis Life and Habits
What do plumbeous ibises eat?
The plumbeous ibis eats water creatures like snails (especially apple snails), mussels, crabs, frogs, fish, and eels. They have also been seen eating snakes, lizards, and insects that live on land. Even though they eat many different things, they mostly eat molluscs in the Paraguay-Parana basin.
The plumbeous ibis often feeds alone or in pairs. They might gather in loose groups to find food in winter when it's harder to find. They walk slowly through shallow mud and water, quickly poking their bills into the water to find prey. Sometimes their whole bill goes underwater.
How do plumbeous ibises raise their young?
Both parent ibises feed their young by bringing up food from their stomachs. The chicks poke their bills into the parent's bill to get food. As the young birds get older, they start to leave the nest and find food more on their own.
Plumbeous ibis reproduction
Unlike many other ibises, the plumbeous ibis does not nest in large groups. They build their nests in areas with scattered trees, from March to mid-October. Both parents work together to build the nest, which takes about a month.
Nests are usually built on horizontal branches of large fig trees or other trees, often above or near water. Some nests have been found near farmhouses, showing that these birds can live close to humans. The nest is a loose platform of dry branches and sticks, with a hollow in the middle lined with grass and leaves. It looks like a wood stork's nest. Nests are usually 10-12 meters high, but can be up to 20 meters high in very large trees. A pair might use the same nest for many years.
Mating happens in April, after a simple courtship. One bird stands on a dead tree branch and makes its metallic call to attract its mate. When the mate arrives, both birds poke their bills into the tree bark. Then the male buries his bill in the female's feathers.
A typical nest has 2-3 pale greenish-grey eggs, each weighing about 70-74g. Sometimes, nests have eggs and young birds at different stages, which might mean the ibis lays two sets of eggs in one year. The eggs hatch after 28 days, usually in early September.
For the first 10 days, one parent always guards the chicks. At night, the parents take turns guarding the nest. The returning parent signals the change with calls and by poking their bills into each other's neck feathers.
As the chicks grow, parents spend less time at the nest. Breeding pairs usually raise two young birds that learn to fly after 40–43 days. This happens at the end of the dry season. The young birds start to leave the nest and feed in nearby marshes. Parents have been seen flying to meadows near the nest tree, making calls that seem to invite the young to follow them to adult feeding areas. The young then feed with the adults and continue to use the nest tree for sleeping for several weeks after they can fly.
What threatens the plumbeous ibis?
Many animals try to eat plumbeous ibis eggs and chicks. Adult ibises are very aggressive towards small predators like opossums, jays, and vultures. But they can lose to larger predators like capuchin monkeys and large hawks. For example, groups of capuchin monkeys have been seen attacking ibis nests, with some monkeys forcing the parent off the nest while others steal the eggs.
Adult ibises also act aggressively towards humans who get too close. If a human approaches, the ibis screams loudly, lowers its body, ruffles its feathers, and jabs its bill. Young ibises also defend themselves by lunging forward with their bills. These behaviors show that the ibis faces many dangers and needs these ways to protect itself.
Like many other wading birds, the plumbeous ibis is likely threatened by habitat loss. This can happen from burning and cutting down nesting trees, building dams, and expanding mining and farming. However, people do not usually hunt this bird directly.
Because this ibis often lives near humans, it might be at risk from pesticides used in farming. Pesticides and farm machinery can reduce the number of small creatures the ibis eats. One study showed that plumbeous ibises were more common in flooded rice fields after harvest. This might be because less chemicals and machinery are used then, leading to more food for the ibis. Still, these birds are usually more common in natural wetlands than on farms. To help protect them, it's suggested that natural wetland areas should be kept within farming regions.
Plumbeous Ibis and Humans
People don't usually hunt this ibis because it's hard to kill and skin. It also gives off a strong, unpleasant smell if caught. However, some have been kept in zoos. For example, Berlin Zoo received three plumbeous ibises in 1987. More recently, many Brazilian zoos have kept them, and a chick successfully hatched at Brasilia Zoo in 1992.
Plumbeous Ibis Status
The IUCN (International Union for Conservation of Nature) has listed the plumbeous ibis as a species of Least Concern since 2004. This means it's not currently at high risk of disappearing. Scientists estimate there are between 50,000 and 100,000 plumbeous ibises in the world. However, more information about this bird's life is needed to help protect it better and prevent future population declines.
Images for kids
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A plumbeous ibis in its natural habitat.
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Map showing the current range of the plumbeous ibis.
