Maguari stork facts for kids
Quick facts for kids Maguari stork |
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| Conservation status | |
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Ciconia
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| Species: |
maguari
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| Nonbreeding Year-round | |
The maguari stork (Ciconia maguari) is a large bird that lives in wetlands across much of South America. It looks a lot like the white stork, but it's a bit bigger. This stork is the only one of its kind found in the New World. It's one of just three stork species in the Americas, along with the wood stork and the jabiru.
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Meet the Maguari Stork
The maguari stork was first officially described in 1789 by a German scientist named Johann Friedrich Gmelin. He gave it the scientific name Ardea maguari. Later, it was moved into the Ciconia group, which is the Latin word for "stork." Its name, maguari, comes from the Tupi language and means "heavy bill." This stork is a unique species, meaning it doesn't have any different types or subspecies.
Scientists once thought the maguari stork belonged to its own group, Euxenura. But they later realized it was very similar to other storks in the Ciconia group, like the white stork and the Oriental stork. They look alike and act in similar ways. For example, they all do a special "up-down greeting" dance.
Some old stork fossils found in North America, called Ciconia maltha, seem to be a link between the maguari stork and the white stork. This suggests they might have had a common ancestor that lived a long time ago.
What Does a Maguari Stork Look Like?
Adult Storks
These storks stand about 97 to 120 centimeters (3.2 to 3.9 feet) tall. Their wings can spread out to about 155 to 180 centimeters (5.1 to 5.9 feet) wide. This makes them similar in size to the white stork. Male maguari storks weigh around 4.2 kilograms (9.3 pounds), while females are a bit lighter at 3.8 kilograms (8.4 pounds).
Most of an adult stork's body is white. Its flight feathers and forked tail are black. The white feathers under its tail are longer than the tail itself. This makes them stick out and might help the bird fly. You can easily spot the forked tail when the stork is flying, which helps tell it apart from the white stork.
When flying, these storks are impressive. They soar high in the sky, sometimes hundreds of meters up. They stretch their necks and legs out straight. They flap their wide wings to gain speed, then glide for long distances. They need to take three big jumps to get off the ground.
Before the breeding season, storks grow new, brighter feathers. This helps them look their best for finding a mate. The feathers on their head and neck are long and can stand up. These are important for showing off during courtship or when they feel threatened.
Their bill is straight and bluish-grey with red parts. The last third of the bill is dark maroon. Their eyes are lemon-yellow or cream-white. Their legs are purplish-red. The skin on their throat and around their eyes is orangey-red. This skin turns a deeper red during courtship. Males and females look very similar, but males are usually a bit bigger and have a slightly curved bill.
Young Storks
A special thing about maguari storks is that their young chicks are dark-colored for most of their time in the nest. When they first hatch, their fluffy down feathers are snowy white. But after about four days, black feathers start to grow on their head and neck. After a week, grayish-black down feathers cover their body. For a short time, they look mottled black and white before becoming mostly dark grey.
When they are dark, their bill, legs, and feet are shiny black. They have a pale yellow stripe on their belly. Their throat pouch is bright orange, and their eyes are dark brown. When they hatch, nestlings weigh about 76 to 90 grams (2.7 to 3.2 ounces).
After three weeks, the black down feathers get olive streaks. The only parts that aren't dark are the bright orange throat and a small patch of white down near their tail. About 10 days later, black flight feathers grow, followed by black body feathers. At this point, the chicks are ready to fledge (fly for the first time). They have their first full set of dark juvenile feathers. The orange throat pouch also turns pale red.
In their second feather change, white down feathers start to return when the chicks are seven weeks old. Then white semi-plumes and white body feathers grow. After three months, they have their first white adult-like feathers. By this time, their legs and feet start to turn pink, and their bill becomes blue and maroon.
Even though they look like adults, the skin around their eyes stays black for about a year before turning red. Their dark brown eyes don't start to turn yellow until they are two years old. So, if you see a maguari stork with dark eyes, it's probably a young one.
Scientists have two ideas why the young storks are dark. First, the dark feathers might help them hide from predators on the ground or in the air. Second, the black feathers might help them absorb more sunlight to stay warm. This could be helpful because these storks breed during winter in the southern parts of their range, when it can be cold.
Stork Sounds
Adult maguari storks make wheezing, hissing, two-part whistles. They make these sounds during their greeting displays at the nest, about every 1 to 1.5 seconds. These whistles are slower and lower than those of other storks. Their quiet calls might be a way to avoid attracting predators, especially since they often nest on the ground. Young storks make begging calls that sound like Ehehe-ehehe.
Where Do Maguari Storks Live?
The maguari stork lives in many parts of South America, mostly east of the Andes mountains. You can find them in places like the Llanos of Venezuela and eastern Colombia, Guyana, eastern Bolivia, Paraguay, Brazil (though rarely in the Amazon), Uruguay, and Argentina. They are sometimes seen west of the Andes, like in Chile, but they probably don't breed there. They are also rare visitors to the coast of Suriname and have been seen in Trinidad and Tobago.
They are very common in the Chaco region of Argentina. Many storks, sometimes in groups of 30 to 40, travel there in winter from the southern parts of their range to find warmer weather. They are also common in Brazil, Paraguay, and the Pampas of Argentina.
Maguari storks live in open, low-lying wetlands with shallow water. This includes tropical wet grasslands, marshes, muddy areas, and flooded fields. They sometimes visit dry fields but always stay away from forests. During the dry season, many storks gather around small water bodies where food is easy to find.
The maguari stork shares its home with the jabiru and wood stork in some areas, especially in the Venezuelan llanos. Among all American storks, the maguari stork has the smallest area where it lives.
How Do Maguari Storks Live?
What Do They Eat?
Maguari storks eat a wide variety of foods. They are considered "generalists," meaning they aren't picky eaters, unlike the wood stork and jabiru. They eat fish, frogs, eels, earthworms, insects, insect larvae, snakes, freshwater crabs, small mammals like rats, and bird eggs. Sometimes, they might even eat smaller birds.
Maguari storks prefer to hunt in shallow water, about 12 centimeters (5 inches) deep. They rarely hunt in water deeper than 30 centimeters (12 inches). This might be because shallow waters have more prey or are rich in nutrients. They mostly hunt by sight. They walk slowly through wetlands with their bill close to the water's surface, ready to grab any prey they find. They breed early in the rainy season when the water is clear. This makes it easier to see prey for their chicks. Sometimes, they also feel for food with their bill in the water, especially when water bodies start to dry up and get muddy.
During the breeding season, maguari storks usually hunt alone or in pairs. But outside of breeding season, they might feed in larger groups, often with other wading birds.
Even though they mostly rely on shallow water for food, they have also been seen hunting alone in dry fields. Here, they might find mice, toads, or insects that have been disturbed. In the evenings during the dry season, large groups of storks gather around low-lying water spots where food is concentrated. The maguari stork's ability to hunt in both wet and dry areas shows it's a generalist, while other storks like the jabiru depend more on wetlands.
In one study, a group of 90 maguari storks was seen with jabirus and wood storks in ponds during the dry season. When there's not much food, birds might compete or even steal food from each other. Maguari storks mostly steal from each other, but jabirus sometimes steal large prey like eels from them.
Maguari storks have been seen lifting cowhides in dry fields to find insects underneath. This happens when large groups migrate and look for bugs in bushes and short grass. Some storks even eat pieces of cow dung.
Parents bring food to their nestlings, including fish, eels, small mammals like rats, and insects. The type of food depends on what's available each year, but mostly it's aquatic creatures. Parents carry the food in a large ball in their throat. They throw it up onto the nest, and the nestlings eat it. For very young chicks, they throw up small pieces, but for older ones, it's one big mass.
Reproduction and Life Cycle
Many parts of the maguari stork's breeding and nesting habits are special and different from other storks. These differences probably helped them survive in their open wetland homes.
Nesting Habits
Unlike most storks, the maguari stork often builds its nest on the ground. Other storks usually nest high up. Their nests are always near shallow water, among tall grass and reeds. This is because their chicks mostly eat water creatures. The maguari stork's nest is also unusual because it's made mostly of grass and reeds.
Ground nests in the southern parts of their range are cone-shaped, about one meter (3.3 feet) high. They are 1.5 to 2.5 meters (4.9 to 8.2 feet) wide at the bottom and taper to a flat top of 1 to 1.5 meters (3.3 to 4.9 feet). The nest rises about two feet above the water's surface and is usually in an area with no trees. Their nests look more like those of cranes than other storks.
In the Venezuelan llanos, maguari storks also nest in low, thick-trunked trees. These nests are made of sticks. They probably only nest in trees if they have to, because they can't stand on their back toe like other storks. A pair might use the same nest for many years, sometimes up to seven. However, ground nests made of plants usually fall apart after a year. If this happens, the pair will return to the same spot to rebuild it. Both parents help build and line the nest, even while eggs are incubating.
Maguari storks usually nest in groups, called colonies, but sometimes they nest alone. Nests in colonies are more successful, meaning more young survive. Colonies usually have 5 to 15 nests, some as close as 50 centimeters (20 inches) apart in tree colonies. One colony had as many as 40 nests.
Storks in colonies are more aggressive than solitary nesters. They will physically attack intruders by jabbing with their bills. Storks nesting alone use a "lead-away" strategy. They walk behind an intruder, making threatening bill-clattering sounds. They stop clattering when the intruder moves away from the nest.
Courtship and Nesting Displays
Maguari storks gather in groups to find mates before moving to their nesting sites. This is different from white storks, who court directly at the nest. These mating gatherings happen in freshwater marshes that are flooded with about 20 centimeters (8 inches) of rainwater. This is where young storks find new partners or old mates reunite.
This stork has unique nesting behaviors that help it when nesting on the ground. For example, it does a special "Nest Covering Display" to protect its chicks from predators. During this display, the stork droops its wings, cocks its tail, and raises the feathers on its head and neck. It also clatters its bill, pointing it almost straight down.
Another unique behavior is the "Mock Resting display." If an intruder is near the nest, the stork stands still with its back arched, neck pulled back, and wings and bill folded down. This pose helps it blend in with the grass and reeds, making it hard for an intruder to see. At the same time, the bird is ready to attack.
While maguari storks have many common stork courtship displays, they seem to use fewer loud sounds and visual shows. Instead, they use more touch-based actions. This might be another way they've adapted to ground nesting. Quieter displays are less likely to attract predators who hunt by sight or sound.
Eggs and Nestlings
Breeding starts when the rainy season begins, usually from May to November in Venezuela. Most maguari storks breed from July to mid-September. This is earlier than the wood stork and jabiru. Storks start migrating to their breeding grounds as the rains begin. Even though the wet season is long, nesting never lasts more than four months in a year.
A female stork usually lays 3 or 4 eggs, with an average of 3.2 eggs per nest. Eggs are laid every other day, so the chicks hatch at different times, sometimes up to a week apart. Both parents take turns sitting on the eggs, starting after the 2nd or 3rd egg is laid. Incubation lasts 29 to 32 days. The eggs are oval-shaped and average about 75.19 mm (3 inches) long and 52.56 mm (2 inches) wide. They are quite small compared to the mother's body size.
Chicks of different ages in the same nest can have weight differences of 500 to 1400 grams (1.1 to 3.1 pounds). However, all the nests in a colony tend to lay eggs around the same time. This means many young storks from different nests fledge (learn to fly) together at the end of the wet season. This might be a way to protect themselves from predators, as there are too many young birds for predators to catch them all. Male maguari storks can start having chicks at three years old, and females at four years old.
After three weeks, maguari stork nestlings develop a special defense behavior if someone comes near their nest. This is not common in other stork species. They crouch forward, spread their wings a little, and raise the black feathers on their head, neck, and back. Then they let out a loud, harsh scream and try to grab the intruder with their bill. This aggressive behavior probably developed because their nests are on the ground and the young chicks can't leave the nest easily.
There isn't much fighting between siblings in maguari stork nests. Most chick deaths happen when young birds fall out of nests with 3-4 chicks. More eggs are lost to predators than chicks.
Large groups of maguari storks seen before and after the breeding season are a good sign that these birds are breeding in that area.
Dangers and Survival
The biggest threats to maguari storks are human activities that disturb their homes and hunting for food. People sometimes destroy their habitat by draining marshes for farming, especially in southeast Brazil. This is a concern for the species in that area. Building canals, filling in land, and sewage can also harm their feeding areas during the dry season.
Maguari storks are vulnerable to habitat destruction because they tend to use the same nesting spots year after year, even if humans start disturbing the area. Pesticides can also harm their health and breeding success. People also hunt them for food, especially in the Southern Amazon and Venezuela.
Natural enemies of this stork include boa constrictors and crested caracaras, which eat their eggs. These predators can also eat young maguari stork chicks. Other animals like jaguars, crocodilians, Pampas cats, and maned wolves could also reach ground nests. While these animals are known to eat birds, there haven't been any recorded cases of them preying on maguari storks, but it's possible.
The maguari stork might be threatened in the Pantanal region. Besides farming, more hydroelectric dams are being built there. Dams hold back water during the dry season, which can cause natural water areas downstream to dry up. This means fewer places for the storks to find food. During the wet season, dams can release a lot of water at once, causing floods. This makes the storks' usual feeding grounds too deep for them to stand in.
Maguari Storks and Humans
Maguari storks have been kept in zoos in the past, like the London Zoo in the mid-1800s and the Amsterdam Zoo in the late 1920s. One stork lived for over 21 years in captivity. There have been two cases of them breeding in zoos. A chick hatched at the Buenos Aires Zoo between 1946 and 1950, but it didn't survive. Five chicks hatched at Discovery Island at Disneyland Florida Resort in 1991, and three of them survived. In the wild, the maguari stork is sometimes hunted for food in the Amazon region.
Stork Status
The maguari stork is currently listed as a species of "least concern" by conservation groups. This means it's not considered to be in danger. It lives in a very large area, and its population seems stable and very large. Even though there are fewer storks in some local areas, the overall population is not threatened globally.
However, even though there seem to be many maguari storks, scientists don't have exact numbers for the world population. This should be a new goal for conservationists. Doing aerial surveys of nesting areas could help get a clearer idea of how many maguari storks there are.
The stork's population in the llanos of Venezuela dropped a lot in the past. A good way to help protect their habitat there is to keep cattle ranches instead of growing crops. These ranches are similar to natural grasslands. Another helpful idea is to put up artificial nesting platforms to encourage storks to nest, like they do for white storks in Europe. Even though the maguari stork isn't globally threatened, it's important to keep watching its population to protect it from future big declines.
Images for kids
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A Maguari Stork in its natural habitat.
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Map showing the Maguari Stork's range.
