This month we are spotlighting a very special and under-appreciated bird; the hamerkop. The hamerkop is an African bird slightly smaller than a raven and a uniform brown in color. The name “hamerkop” comes from Afrikaans and translates to “hammer-head”. As the name suggests, the hamerkop’s head is in fact hammer-shaped. They have long, dark brown bills that are straight and sturdy and end on a hook. The bill is countered by a long crest of feathers protruding from the back of the birds head.
Other than the oddly shaped head, hamerkops are not the most striking of birds. Our hamerkop, here at Safari West, is easily overlooked. He lives in the walk-through Amani Oasis Aviary where he has to compete for attention with brilliant scarlet ibises, vibrant blue crowned pigeons, and the magnificent Lady Amherst’s pheasant. Amongst such colorful company, our little brown hamerkop is a bit underdressed. Though he may be easy to miss, our industrious little hamerkop’s nest is not.
Hamerkops construct some of the largest and most elaborate nests in the world. Ours is no exception and his current masterpiece is located in a tree on the south side of the aviary. When he started construction, it looked like he was building a broad platform nest like those used by many storks and eagles. Soon, however, high walls curved up from all sides of the platform. As the walls rose it became clear that he was building an opening in one side of the nest; a round portal into what would become a completely enclosed chamber. After four to five weeks of construction, he began to put a roof on the structure. The roof is typically the sturdiest part of a hamerkop nest and is visibly thicker than any other portion. When he completed the basic construction, our hamerkop went to work plastering the interior of the nest with collected mud and leaves. It’s quite a lovely home he’s built.
In the wilds of sub-Saharan Africa where hamerkops are found, these massive nests tend to average four to five feet in diameter and are incredibly resilient. They are nearly always built in the crook of a sturdy tree although occasionally some nontraditional hamerkop will construct their nest along a cliff ledge instead.
There hasn’t been much study done on the hamerkop and so the purpose of this fortress of a nest is to date, poorly understood. Surprisingly, however, in spite of the labor-intense nature of building such a structure, hamerkops are relentless carpenters. They tend to form long-term pair-bonds and on average, each pair will construct three to five of such nests in a given year. In one study a single pair of hamerkops constructed eleven nests in four and a half years. They moved regularly between two old nests and the eleven new ones and in that same span of time relocated a total of seventeen times. This behavior is also not well understood.
With such a hectic and relentless pace of nest-building, it may come as no surprise that hamerkops abandon many nests half-built and many of those they do complete they never occupy. Which is not to so that nobody else does. Several bird species, ranging from barn owls to Egyptian geese are known to take up residence in hamerkop nests. Other common squatters include genets, monitor lizards, mongooses, a whole variety of snakes (including spitting cobras), and swarms of bees. These sturdy nests can persist for years even without the regular maintenance of their original builders.
Hamerkops are found across an immense range and are common throughout the entirety of sub-Saharan Africa and Madagascar. They don’t seem too concerned about the overall environment—whether tropical forest, scrubby grassland, or semi-desert—so long as there is a shallow water source nearby. The hamerkop is an avid fisher and their diet consists almost entirely of fish, amphibians, shrimp, worms, insects, and perhaps the occasional small mammal.
The combination of their wide-ranging distribution, generalists diet, and the fact that they aren’t normally persecuted by humans means that these birds are abundant in the wild and their population is currently under no threat. The reasons why they aren’t persecuted by humans are both fascinating and mysterious. There is a great deal of mythology and folklore surrounding the bird. Anecdotes abound relating the bird’s role in the traditional beliefs of many African cultures and tribes. These stories are largely apocryphal and unattributed, but they paint a broad picture of a bird that is widely revered in tropical regions and widely feared in much of the south of the continent. Among the stories told are many painting the hamerkop as an omen of evil or death. Others describe the hamerkop as symbolic of human vanity and futility.
The birds are often seen standing in the shallows raking at the mud with their clawed feet. They do this to drive out prey species hidden in the mud, but some anecdotes claim they’re actually stirring up visions of the future and prophesizing tragedy and death. The long and short of it is that across the continent, most cultures advocate leaving a hamerkop to its own devices; either out of reverence or fear. The birds benefit tremendously from the general lack of conflict with the humans they live alongside.
These are exciting times at Safari West as we have recently introduced a newly arrived female to our once lonely hamerkop male. They are highly gregarious birds and so the introductions went quite smoothly. Since meeting one another, the two birds have been spending a great deal of time together. They’re highly vocal and seem to have adopted the male’s pre-built nest. There appears to be some courtship behavior happening, but in truth, it’s not always easy to tell with hamerkops. The mounting behavior that usually signifies breeding in birds is also part of a common hamerkop social display. Among wild hamerkops, “false-mounting” is common and includes not only males mounting females, but females mounting males as well as same-sex mounting displays. As with so much of hamerkop life, the motivations driving this behavior are not well understood.
It’s much too soon to know whether or not these two will breed or reproduce successfully, but simply having the two of them together opens up opportunities for observation and study that weren’t possible with just our stalwart male. Join us at Safari West as we watch these two fascinating birds interact, court, and live out their lives in our open-air aviary.