Among animals, birds are renowned for being highly skilled builders, able to construct complex nests made of sticks, grass, mud or other materials. What makes this really amazing is that they do it with nothing but their beak and feet. They do not have the luxury of hands like we do. Birds' nests come in a wide variety of shapes and sizes, from simple flat platforms to complex chambers with multiple tunnels, entrances and exits.
Today we will take a look at one of the most impressive builders of the bird world. It is reputed to build the largest nest of all African birds. This is non other than the Hamerkop (Scopus umbretta).
A Hamerkop at Lake Victoria. The name Hamerkop means 'hammer head' in Afrikaans. Looking at the shape of its head, you can see where it got its name from.
A large Hamerkop nest can be nearly 2 meters wide and is so strong that a man can stand on it. Not bad for a bird that weighs half a kg.
Hamerkop nest at Elsamere Field Study Centre, Naivasha. Compare it with the cars parked below to get an idea of how big it is. This is in fact an average nest by Hamerkop standards.
Nests are built mainly using sticks and mud, but many other random materials (e.g. feathers, pieces of cloth, bones, plastic and pretty much anything the birds can find) are added. Whether these are added to strengthen the nest or decorate it is anyone's guess.
Hamerkops are monogamous and stay together for life. Nest-building is thought to help keep the bond between a pair strong, And they seem to really enjoy it. In fact they build nests not just when breeding but throughout the year. They build like they're getting paid for it. They can keep adding material to a nest for years and a nest that has been used for several years can grow particularly massive.
It's also not unusual for a pair to build several nests close together. I came across this tree with three nests in it while doing bird of prey surveys in Kajiado. You might find that the pair only used one for actually nesting in and the rest were built just for the heck of it. The extra nests might also serve as a decoy to distract a potential predator and give the pair and their young a chance to escape.
Hamerkops are important in ecosystems as their nests are used by several other animals including genets, rodents, snakes and falcons. In some cases this involves the Hamerkops being forced out but most times it is the abandoned/unused nests that get occupied. Sometimes different species might even nest in different corners of the nest while the Hamerkops continue to use the nest. The huge nest size makes this possible.
Hamerkops are common throughout Kenya wherever there is a water body, stream or swamp where they can find frogs, fish and other aquatic prey to eat.
Hamerkop at Lake Jipe
Next time you go birding, make sure to submit your bird records to the Kenya Bird Map project to help map the current distribution of Hamerkops and other birds throughout Kenya.
Keep learning about the incredible birds of Kenya through the rest of the Ndege Wetu series.
Learn more about the amazing birds of Kenya and other parts of Africa from our Birds of Africa blog.
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