Hawaiian duck facts for kids
Quick facts for kids Hawaiian duck |
|
|---|---|
 |
|
| Conservation status | |
| Scientific classification | |
| Genus: |
Anas
|
| Species: |
wyvilliana
|
The Hawaiian duck (Anas wyvilliana), also called the koloa, is a type of bird that lives only on the large islands of Hawaiʻi. It belongs to the duck family, Anatidae. The koloa is very similar to the mallard duck. However, unlike mallards, both male and female Hawaiian ducks look alike, and they do not fly to different places for seasons.
Hawaiian ducks and mallards can have babies together. Because of this, the koloa was once thought to be just a type of mallard found on islands. But now, experts agree that the koloa is its own unique species. Scientists believe it came from a mix of mallards and Laysan ducks a long time ago. In the Hawaiian language, this duck is called koloa maoli (meaning "native duck"), or simply koloa. This duck is currently listed as endangered, which means its numbers are going down.
Contents
About the Hawaiian Duck
What They Look Like
Both male and female Hawaiian ducks are a mottled brown color, looking a lot like a female mallard. The males are usually a bit bigger than the females. Both sexes have special green or blue feathers on their wings, with white edges. Their tails are dark, which is different from the black and white tails of mallards. Their feet and legs are orange or yellow-orange.
Male ducks have an olive-green bill, while females have a dull orange bill with dark spots. Adult males often have a darker head and neck, which can sometimes look green. Females are generally lighter in color and have plainer feathers on their backs. It can be tricky to tell Hawaiian ducks apart from female mallards or mixed ducks because their colors can vary.
How Big Are They?
Male Hawaiian ducks are usually about 48–50 cm (19–19.5 in) long. Females are a bit smaller, around 40–43 cm (15.5–17 in) long. On average, a male weighs about 604 grams (21.3 ounces), and a female weighs about 460 grams (16 ounces). Hawaiian ducks are typically 20 to 30 percent smaller than mallards.
What Do They Eat?
Hawaiian ducks are "opportunistic feeders," which means they eat whatever food they can find. Their diet includes plants that grow in freshwater, snails, insects, and other small water creatures. They are known to eat things like insect larvae, earthworms, tadpoles, crayfish, mosquito larvae, and even grass seeds and rice. They also eat green algae.
What Do They Sound Like?
The Hawaiian duck makes a quacking sound, just like a mallard. However, their quacks are softer and they don't quack as often.
Hawaiian Duck Behavior
The Hawaiian duck is a very shy bird. You'll often find them in pairs rather than in big groups. They mostly live in tall, wet grasses and near streams, especially around the Kohala volcano on the main island of Hawaiʻi. They are very private birds and don't usually hang out with other animals.
Native Hawaiians have a saying that the Hawaiian duck can only get wet when the gods say it can. This means the duck seems to walk around the water, but it's actually looking for fish to catch and eat.
Reproduction and Life Cycle
Some Hawaiian duck pairs nest all year round. However, their main breeding season is from December to May. During this time, pairs often do amazing flights together. A female usually lays about eight eggs, but it can be anywhere from two to ten. She builds a hidden nest and lines it with soft feathers from her chest.
The eggs hatch after about four weeks. The baby ducks can swim very soon after they hatch! But they can't fly until they are about nine weeks old. Young ducks can start having their own babies after they are one year old.
Female Hawaiian ducks are sometimes attracted to male mallards, which are more common in the same areas. When Hawaiian ducks and mallards breed together, they create babies that can also have their own babies. This mixing of species is one of the main reasons why the Hawaiian duck is endangered.
Where They Live
In the past, Hawaiian ducks lived on all the main Hawaiian islands except Lānaʻi and Kauaʻi. They could be found on warm coasts with ponds and even in mountains up to 7,000 feet high. This includes wet lowlands, river valleys, and mountain streams.
Today, "pure" Hawaiian ducks are mostly found only on Kauaʻi. They were once gone from other islands, but people tried to bring them back to Oʻahu, Hawaiʻi, and Maui by releasing ducks raised in captivity. However, these ducks bred with wild mallards, creating mixed babies.
There are about 2,200 Hawaiian ducks left. About 2,000 are on Kauaʻi and 200 on Hawaiʻi. Their numbers are decreasing because of breeding with mallards. They are also in danger from predators like cats, pigs, dogs, and mongooses, because their nests are built low on the ground. Kauaʻi has also lost many of its lowland wetland homes, which affects the ducks.
Protecting the Hawaiian Duck
Why They Are in Danger
One of the biggest threats to the Hawaiian duck is called hybridization. This happens when Hawaiian ducks breed with wild mallards. Since this has been happening for a long time, it's hard to find any "pure" Hawaiian ducks left. Scientists are working to find ways to tell the difference between pure Hawaiian ducks, female mallards, and mixed ducks. Once they can do this, they can remove the mixed ducks to help save the pure Hawaiian duck genes.
It has been shown that when mixed Hawaiian duck/mallard babies breed with pure Hawaiian ducks, over time, the mallard genes become less common. This gives hope for bringing back the natural population. Efforts are being made to remove mallards from the islands to protect the Hawaiian duck's unique genes.
Other Problems for the Ducks
The Hawaiian duck population is also affected by losing their homes, changes to wetlands for flood control, invasive plants, diseases, pollution, hunting, and predators. Diseases like avian malaria and avian pox have harmed many Hawaiian forest birds. Predators like wild cats, rats, and small Asian mongooses eat the ducks' eggs and young.
Dogs and even other introduced birds and fish also threaten Hawaiian ducks. Hunting of water birds in the 1800s and 1900s also greatly reduced their numbers. City growth and using land for farming also destroy their natural homes. When their homes are destroyed, the ducks have to move, which can lead to problems like drought. In the late 1800s, mallards were brought to Hawaii for ponds, and then many more were imported in the 1950s and 1960s.
The mixed ducks that result from breeding with mallards seem to be less able to survive in the local environment. This mixing is common because there are so many wild mallards. Some attempts to bring Hawaiian ducks back to certain areas have failed because the mixed ducks raised in captivity didn't do well in the wild. Also, turning wet taro fields into dry sugar cane fields destroys parts of the ducks' habitat.
What Is Being Done to Help
Wildlife refuges, like the Hanalei National Wildlife Refuge on Kauaʻi, are very important places for Hawaiian ducks to breed, especially during cold winters when their natural homes might not be suitable.
The species was first brought to Oʻahu between 1958 and 1982, with about 326 captive birds released. Later, in 1989, twelve more birds were released on Maui. The species was also brought back to the "Big Island" of Hawaiʻi between 1976 and 1982. In the 1980s, bringing mallards into Hawaii was limited to help reduce mixing with Hawaiian ducks.
Other efforts to help the Hawaiian duck include creating ways to identify mixed ducks. This involves using both genetic tests and looking at their physical features.
Plans for Recovery
Many plans are in place to help the Hawaiian duck survive, but more information is still needed. We need to learn more about how to tell mixed ducks apart (it's hard to do just by looking, so genetic tests are needed). We also need to know more about protecting their homes, their movement patterns, and how different wetlands affect them. This is an ongoing effort that needs constant attention. The more accurate research we have, the better we can decide where to spend money to help the Hawaiian duck survive.
The Hawaiian Bird Conservation Action Plan has a five-year plan to deal with the main threats to the species. This includes managing the mixing of ducks by removing wild mallards and mixed ducks as much as possible. They also want to get the public to agree to control wild ducks, continue protecting and restoring important wetland homes, and find new ways to control predators, like using fences. This plan is estimated to cost about five million dollars.
See also
In Spanish: Pato hawaiano para niños
