Maguari stork facts for kids

The Maguari Stork (Ciconia maguari) is a large bird that lives in the wetlands of South America. It looks a lot like the white stork but is a bit bigger. It's the only stork of its kind found in the New World (North and South America). It's one of three stork species in this part of the world, along with the wood stork and the jabiru.

About 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 to the group of storks called Ciconia. The name Ciconia is the Latin word for "stork." The name "maguari" comes from the Tupi language, meaning "heavy bill." This stork doesn't have different types or subspecies.

Scientists used to think the Maguari Stork belonged to its own group, Euxenura. But because it looks and acts so much like other storks in the Ciconia group, especially the white stork and the Oriental stork, it was moved. For example, it does a similar "up-down greeting display" like the white stork. Its feathers and the colors of its soft parts (like its bill and legs) are also very similar to these two storks.

Some old fossils of a stork called Ciconia maltha found in North America look like a mix between the Maguari Stork and the white stork. This suggests they might have a common ancestor, meaning they came from the same ancient stork family.

What Adults Look Like

The Maguari Stork stands about 97 to 120 centimeters (3.2 to 3.9 feet) tall. Its wings can spread out from 155 to 180 centimeters (5.1 to 5.9 feet) wide. This makes it similar in size to the white stork. Males are a bit heavier, weighing around 4.2 kilograms (9.3 pounds), while females weigh about 3.8 kilograms (8.4 pounds). It's bigger than the wood stork but smaller than the jabiru.

Most of its body feathers are white. Its flight feathers (the ones used for flying) and its tail are black. The tail is forked, meaning it splits into two points. This forked tail helps tell it apart from the white stork. When it flies, you can easily see its white feathers under its tail. The stork is amazing to watch in flight. It soars high in the sky with its neck and legs stretched out. It beats its wide wings to gain speed for long glides. It needs to take three long jumps to take off from the ground.

Before the breeding season, these storks grow new, brighter feathers. The feathers on their head and neck can stand up, which is important for showing off during courtship and when they are being aggressive.

Its bill is straight and bluish-grey with red parts. The tip of the bill is dark maroon. Its eyes are lemon-yellow or cream-white. Its legs are purplish-red. The skin on its throat and around its eyes is orangey-red, turning a deeper red during courtship. Males and females look very similar, but males are slightly larger and have a bill that curves slightly upward.

What Young Storks Look Like

A special thing about Maguari Stork chicks is that they are dark-colored for most of their time in the nest. When they first hatch, their soft, fluffy feathers (called down) are snowy white. After a few days, black feathers start to grow on their head and neck. Then, greyish-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 and a bright orange throat pouch. Their eyes are dark brown. When they hatch, they weigh about 76-90 grams (2.7-3.2 ounces).

After about three weeks, the black down feathers get olive streaks. The only bright parts are the orange throat and a small patch of white down near their tail. A little over 10 days later, black flight feathers and body feathers grow. At this point, the chicks are ready to fly and have their first full juvenile plumage. They stay black when they fledge (learn to fly), and their orange throat pouch turns pale scarlet.

When the chicks are about seven weeks old, white down feathers start to return. Then, white body feathers grow. After three months, they have their first white plumage, which looks like an adult's. By this time, their legs and feet start to turn pink, and their bill becomes pale blue and maroon. Even though they look like adults, the skin around their eyes stays black for about a year. Their dark brown eyes don't turn yellow until they are over two years old. So, the dark eyes are the easiest way to tell young Maguari Storks from adults in the wild.

Scientists have two ideas about why the young storks are dark. First, the dark feathers might help them hide from predators on the ground and in the air. Second, the black feathers might help them absorb more sunlight to stay warm. This could be helpful because they breed during winter in the southern part of their range, when it can be cold. However, the idea that it helps them hide from predators seems more likely.

Sounds They Make

Adult Maguari Storks make wheezing, hissing, two-part whistles when they do their greeting displays at the nest. These whistles are slower and lower-pitched than those of other storks. They sound similar to the calls of the Abdim's stork and the woolly-necked stork. These quieter calls might be an adaptation to their ground-nesting habits, helping them avoid attracting predators. Young storks make begging calls that sound like "Ehehe-ehehe."

Where They Live and Their Home

The Maguari Stork lives across a large part of South America, mostly to the east of the Andes mountains. You can find them in the Llanos of Venezuela and eastern Colombia, Guyana, eastern Bolivia, Paraguay, Brazil (though rarely in the Amazon), Uruguay, and Argentina. They are not as common west of the Andes, like in Chile, and probably don't breed there. They are sometimes seen visiting the coast of Suriname and have been reported in Trinidad and Tobago.

They are very common in the Chaco region of Argentina. Many storks, sometimes in flocks of 30-40, migrate there in winter from the southern parts of their range to find warmer weather. They are also common in Brazil, especially in the state of Rio Grande do Sul, Paraguay, and the Pampas of Argentina. Large numbers migrate to the Pantanal in the wet season. However, scientists don't fully understand all their migration routes yet.

Their home is usually open, low-lying wetlands with shallow water. This includes wet grasslands, marshes, muddy areas, and flooded fields. They sometimes visit dry fields but always stay away from forests. During the dry season, many Maguari Storks gather around low water areas where food is easier to find.

The Maguari Stork often lives in the same areas as the jabiru and wood stork, especially in the Venezuelan llanos. Among all American stork species, the Maguari Stork has the smallest natural range.

How They Live and What They Do

What They Eat

The Maguari Stork eats a wide variety of foods. It's considered a "generalist," meaning it's not picky, unlike the wood stork and jabiru. It eats fish, frogs, eels, earthworms, insects, insect larvae, snakes, freshwater crabs, small mammals like rats, and bird eggs. Sometimes, it might even eat smaller birds. For example, one stork was found with a whole rail (a type of bird) in its throat. One study in Brazil suggested they might specifically hunt "worm lizards" (Amphisbaena). This might be because these long, thin creatures fit well in the stork's stomach, helping it get more energy.

Maguari Storks prefer to hunt in shallow water, about 12 centimeters (5 inches) deep, but sometimes up to 30 centimeters (12 inches) deep. This might be because more prey lives in shallow water, or because these areas have more 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 still clear, making it easier to see and catch food for their chicks. However, they have also been seen feeling for food with their bill in the water, especially when water bodies start to dry up and become 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. In these shallow pools, where prey is concentrated, feeling for food with their bill is very effective.

Even though they mostly rely on shallow freshwater for food, they have also been seen hunting alone in dry fields. Here, they might find mice and toads. They also hunt in dry farm fields where insects might have been disturbed. In the evenings during the dry season, large groups of storks gather around low-lying water areas 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 food is limited, birds might compete for it, sometimes stealing food from each other. Maguari Storks mostly steal from other Maguari Storks, 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 especially when large groups migrate and search for insects in bushes and short dry grass. Some even eat pieces of cow dung. In the past, one stork was seen swallowing a whole cowhide.

Parents bring food to their chicks in the nest, including fish, eels, small mammals like rats, and insects. The types of food change each year depending on what's available, but mostly they bring aquatic animals. Parents carry the food in a large lump in their throat. They throw it up onto the nest, and the chicks pick it up and eat it. For very young chicks, the food is thrown up in small pieces, but for older chicks, it's one large mass.

Reproduction and Life Cycle

Many things about how Maguari Storks reproduce and build nests are unique to this species. These differences likely developed because they adapted to live in open, lowland wetlands.

Nesting Habits

Unlike most other 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, because their chicks mostly eat aquatic animals. The Maguari Stork's nest is also unusual because it's made mostly of grass and reeds. They use plants like Cyperus giganteus and Zizianopsis bonariensis, along with other water plants. Ground nests in the southern parts of their range are cone-shaped, about 1 meter (3.3 feet) high, with a base 1.5–2.5 meters (4.9–8.2 feet) wide, tapering to a flat top 1–1.5 meters (3.3–4.9 feet) wide. The nest rises about 60 centimeters (2 feet) above the water and is usually in an area with no trees. So, the Maguari Stork's nest looks more like a crane's or a southern screamer's nest than other storks'.

In the Venezuelan llanos, Maguari Storks also nest in low, thick-trunked trees like Ficus pertusa. These nests are made of sticks, usually less than a meter long and 2 centimeters (0.8 inches) thick, often from palm trees. However, this stork doesn't seem to naturally perch in trees because, unlike other storks, it can't stand on its back toe. So, it probably only nests in trees if it's easy to do so. A pair might use the same nest for several years, sometimes up to seven years. Ground nests made of plants usually fall apart after a year, so the pair returns to the same spot to rebuild it. Both parents help build and line the nest, and they continue to add material even while incubating eggs and caring for chicks. Nest lining starts when the base is about a meter wide, and they use wet grass that dries and hardens in the sun.

Maguari Storks usually nest in groups, forming colonies, but they also sometimes nest alone. Nests built alone are less successful at raising young, but their success rates are more consistent. Colonies typically have 5-15 nests, some as close as 50 centimeters (20 inches) apart in tree colonies. One colony had as many as 40 nests. Storks in colonies defend their nests differently than solitary nesters. Colonial storks are more aggressive and will physically attack intruders by jabbing them with their bill. Solitary nesters use a "lead-away" strategy: the bird walks behind the intruder, making threatening bill-clattering sounds, and stops when the intruder moves away from the nest.

Courtship and Nesting Displays

Even though nesting in colonies is common for storks, the Maguari Stork is different because courtship happens in large groups before the pairs go to their nesting sites. Other storks, like the white stork, court directly at the nest. These courtship gatherings for the Maguari Stork happen in freshwater marshes that are flooded with about 20 centimeters (8 inches) of rainwater. This is where new pairs form or mates from previous years reunite.

This stork has unique nesting behaviors not seen in many other storks, which might be adaptations to nesting on the ground. For example, it's one of the few stork species to perform a "Nest Covering Display" to protect its chicks from predators. During this display, the stork droops its wings, cocks its tail high, 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 strongly arched, neck pulled in, and wings and bill folded almost straight down. This behavior likely helps it hide in the dense grass and reeds, making it hard for an intruder to see. At the same time, the stork is ready to attack.

While this stork shares many common courtship displays with other storks, its displays seem to have fewer loud calls and visual shows. Instead, they have more touching. This might be another adaptation to ground nesting. Quieter visual displays are less likely to attract predators that hunt by sight up close. And while loud calls would help mates find each other, they could also make them more obvious to ground predators.

Egg Laying and Chicks

Breeding starts right when the rainy season begins, usually from May to November in the Venezuelan llanos. However, most Maguari Storks breed from July to mid-September, which is earlier than the wood stork and jabiru. Storks start migrating to their breeding grounds as the rains begin, though some might arrive early. Even though the wet season is long, the nesting period never lasts more than four months in a year. In other parts of their range, the breeding season is slightly different and shorter. For example, in northeast Argentina, it's from June to August.

They usually lay 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 incubate the eggs, starting after the 2nd or 3rd egg is laid. Incubation lasts 29–32 days. The eggs are oval-shaped, averaging 75.19 mm (3 inches) long and 52.56 mm (2.1 inches) wide. They are considered small compared to the female's body size.

Chicks of different ages in the same nest can have weight differences of 500-1400 grams (1.1-3.1 pounds). However, egg laying is very synchronized among nests in a colony. This means large groups of young from different nests fledge (learn to fly) together at the end of the wet season. This might be a strategy to protect them from predators, as there are so many young birds around. Male Maguari Storks can start breeding at three years old, and females at four years old.

After three weeks, Maguari Stork chicks develop a defensive behavior if an intruder approaches their nest, which is not common for other stork chicks. They crouch forward, partly spread their wings, and raise the black feathers on their head, neck, and back. Then they make a loud, harsh scream and try to grab the intruder with their bill. Many other stork chicks stay still for a long time, and their white feathers make them look like eggs to predators. But Maguari Stork chicks stop being still much earlier. Their unusual aggressiveness likely developed as a special way to protect themselves because they can't leave the nest easily (their back toe develops slowly) and their nest is on the ground, making it vulnerable. However, when they are 25–35 days old, their back toe is developed enough for them to leave ground nests to find food. Chicks sometimes beg for food from their parents outside the nest, but parents have never been seen feeding them outside the nest.

There doesn't seem to be 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 gatherings of Maguari Storks before and after breeding season are a good sign that these storks are breeding in that area.

Dangers and Survival

The main dangers to the Maguari Stork are human activities that disturb their habitat and hunting for food. Humans destroy their habitat by draining marshes to create farmland, especially in southeast Brazil. This is a concern for the species in that area. Building canals, filling in land, and releasing sewage can also harm their feeding grounds during the dry season, especially on the northern Rio de Janeiro coast. The Maguari Stork is vulnerable to habitat destruction because it tends to return to the same nesting site, even after human disturbance. The use of pesticides can also harm their health and breeding success. People also hunt them for food, especially in the Southern Amazon and Venezuela.

Natural predators of this stork include boa constrictors and crested caracaras, both of which eat their eggs. These predators can probably also eat young Maguari Stork chicks that are only a few weeks old. Many other potential predators 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 eating Maguari Storks, but it's considered likely.

The Maguari Stork might be threatened in the Pantanal region. Besides farmland expansion, there are more hydroelectric dams operating there, especially in the Parana river basin. Dams hold back a lot of water during the dry season, which can cause natural water areas downstream to dry up completely. This means fewer suitable feeding spots for the storks. On the other hand, during the wet season, dams can release a lot of water at once, causing widespread flooding downstream. This makes the storks' usual feeding grounds too deep for them to stand in.

Maguari Storks and People

Historically, Maguari Storks have been kept in zoos, 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 but didn't survive at the Buenos Aires Zoo between 1946 and 1950. Five chicks, with three surviving, also hatched at Discovery Island at Disneyland Florida Resort in 1991. The parents were at least 18 years old when they first bred. In the wild, the Maguari Stork is sometimes hunted for sport in the Amazon region.

Conservation Status

The Maguari Stork is currently listed as a species of "least concern" by conservation groups. This means it's not considered threatened. It has a very large geographical range, and its global population seems stable and very large. Even though there are fewer storks in some local areas, the overall population is not considered at risk worldwide. However, even though it seems numerous, there isn't a clear count of the world population. Conservationists should aim to get a better estimate of their numbers, perhaps by doing aerial surveys of nesting areas.

The Maguari Stork population in the llanos of Venezuela has declined significantly since the 1970s. In the 1980s, fewer than 5,000 individuals were estimated to live there. One helpful conservation strategy in the llanos could be to expand and maintain cattle ranches instead of growing crops. Ranches have a similar plant structure to natural grasslands, which benefits the storks. Another useful step could be to set up artificial nesting platforms to encourage Maguari Storks to nest, similar to what has been done for the white stork in Europe. Even though its overall status is not threatened, the Maguari Stork should be monitored more closely worldwide to protect it from potential large-scale declines in the future.

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. Blue indicates non-breeding areas, and purple indicates year-round presence.