Black harrier facts for kids
Quick facts for kids Black harrier |
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Circus
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maurus
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The black harrier (scientific name: Circus maurus) is a cool bird of prey found in southern Africa. It lives in countries like South Africa, Botswana, and Namibia. This medium-sized bird has a wingspan of about 105 to 115 centimeters (41 to 45 inches). Its body is usually 44 to 50 centimeters (17 to 20 inches) long.
When a black harrier is resting, it looks completely black. But when it flies, you can see white patches on its back and under its wings. Like other harriers, it has thin wings, a slender body, and a long tail. Male and female black harriers look very similar. Young birds have light brown undersides and many spots on their chests.
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Where Black Harriers Live and Travel
In South Africa, black harriers mostly live along the western and southern coasts. They build their nests either near the coast or in mountain areas inland. They usually avoid places where land has been changed by farming or cities. However, they might still hunt for food in these areas.
Black harriers are migratory birds, meaning they travel long distances each year. Their journeys cover the southern part of South Africa, including Lesotho. But each bird's journey can be a bit different. Most of these birds fly from their breeding areas in southwestern South Africa. They travel east towards the Eastern Cape, KwaZulu-Natal, Mpumalanga, and Lesotho during the summer.
Interestingly, male and female harriers do not travel together. They also don't use the same non-breeding areas. Scientists think black harriers migrate to find enough food. They also travel almost twice as fast after breeding in summer. This is faster than their journey before breeding in winter or spring. This might be because they use the extra time before breeding to find the best places to nest.
Black harriers often return to the same breeding areas they used before. They may even return to the place where they were born to breed. However, some birds might choose new breeding spots far away.
What Black Harriers Eat
Black harriers mainly eat small mammals, like rodents. They also hunt small birds and sometimes reptiles. They catch their food by flying low over their hunting grounds. The Four-striped Mouse is a very common part of their diet.
What they eat can change depending on where they live. Birds living inland might eat more birds than those near the coast. Their diet also changes with the weather. For example, inland, during hot summer days, they eat fewer small mammals. This is because hot temperatures make small mammals less active during the day. Hot weather can also make it harder for small mammals to breed, so there are fewer of them.
In coastal areas, more small mammals are eaten when there is more rain in winter. This is because winter rain helps small mammals reproduce, so there are more of them around.
How Black Harriers Breed
Most black harrier breeding pairs are found in the Western Cape province of South Africa. Here, many pairs gather in loose groups around wetlands near the coast. It is thought that they might breed in Namibia, but this has not been fully proven.
Like other harriers, they build their nests on the ground in tall plants. They lay eggs from June to November, with most eggs laid in July and September. A female usually lays two to four eggs. The eggs hatch after about 35 days.
Studies show that, on average, about 2 to 3 chicks hatch from each nest. About 2 chicks per nest usually grow big enough to fly. About 74% of healthy eggs hatch. However, about a quarter of nests are attacked by predators, meaning eggs or young chicks are eaten.
Scientists think that after a breeding year, black harriers might take a "break" from having babies. This break could help them recover from the stress of raising young.
Protecting Black Harriers
Losing Their Homes
The number of black harriers has dropped a lot recently. There are now fewer than 1000 birds left. Because of this, they are considered endangered in South Africa, Lesotho, and Namibia. This is mainly because their natural home, the fynbos shrubland in South Africa, is being destroyed. People are turning these areas into farms or cities. Also, new types of plants that are not native to the area are taking over.
Because of this habitat loss, black harriers have moved from their lowland homes to mountain areas. These mountain areas are not as good for hunting and nesting. Harriers in the mountains are not as successful as those living near the coast where fynbos still exists. They don't breed as well, eat many different types of prey, and their nests are more often attacked by predators.
Breeding near the coast is more successful. Coastal birds start breeding earlier, hatch more chicks, and more young birds survive to fly. Their nests are also less likely to be attacked. So, changes to the land have really hurt the black harrier population.
Pollution Problems
Carotenoids are natural colors that make birds' eyes and feathers yellow, orange, or red. These colors are important for birds to communicate with each other. For young birds, these colors might help parents know how healthy their chicks are and what they need. Black harrier chicks show these colors a few days after hatching.
Birds cannot make carotenoids themselves; they must get them from their food. Chicks that eat a lot of birds have more carotenoids and brighter colors than those that eat more mammals. However, pollution can affect these colors. Pollutants like heavy metals or chemicals can interfere with how birds use carotenoids. This can make their colors duller and might affect how parents and chicks communicate. For example, black harrier chicks exposed to DDT (a harmful chemical) have fewer carotenoids and duller colors.
