Willem is a wildlife artist based in South Africa. He says "My aim is simply to express the beauty and wonder that is in Nature, and to heighten people's appreciation of plants, animals and the wilderness. Not everything I paint is African! Though I've never been there, I'm also fascinated by Asia and I've done paintings of Asian rhinos and birds as well. I may in future do some of European, Australian and American species too. I'm fascinated by wild things from all over the world! I mainly paint in watercolours. . . but actually many media including 'digital' paintings with the computer!"

Today I bring you a birdie that's dear to my heart! This is Pel's Fishing Owl, one of South Africa's most elusive and sought-after species among birders. About a year ago I saw one for the very first time, on a stretch of the Limpopo River separating South Africa from Botswana. It was an amazing experience, seeing these huge, reddish brown owls in the crowns of the great Nyala Trees. The species is named for Hendrik Severinus Pel, governor of the Dutch Gold Coast, now Ghana, in the mid-nineteenth century.

Pel's fishing owl is one of three owl species in Africa that are adapted to catch fish, the other two being the Vermiculated Fishing Owl and the Rufous Fishing owl. Those two are both much more restricted in their occurrence, confined to equatorial Western and Central Africa. Pel's fishing owl, by contrast, ranges from Senegal to Ethiopia to South Africa. In Eurasia there are a few more owl species that fish, but they appear to not be closely related to the African ones, the similarities being due to convergent evolution. All the fishing owls of the world tend to be reddish brown in colour, and do not have as well-developed facial disks as other owls. The Eurasian fish owls have shaggy head plumage with long ear-tufts, while the African fishing owls have rounded heads lacking ear tufts. While most owls have soft fringes along the edges of their wing feathers, which muffle the sound of their wingbeats, the fishing owls lack these and consequently have fairly noisy flight. Together with the reduced facial disks, this likely means that these owls rely less on sound to locate their prey, and that fish don't have hearing keen enough to discern the wingbeats of owls swooping down from above. All the fishing owls lack feathers on the lower legs, and have special, sharp-pointed 'scales' on the soles of their feet, enabling them to get a firm grasp on their slippery fishy prey.

In South Africa, Pel's fishing owls are associated with large, sluggish rivers, overhung by the leaves and branches of huge riverine trees, in regions with a warm, subtropical or tropical climate. They've historically been found as far south as the Eastern Cape, but at present are known only from northern Kwazulu-Natal northwards. In South Africa, they're known primarily from the Limpopo River, and the Levubu and Olifants, tributaries of the Limpopo. Their greatest stronghold in southern Africa is in the Okavango Swamps of Botswana, a huge wetland region created where the Okavango River drains into the deep sands of the Kalahari Basin, never to reach the ocean. The river branches into thousands of streams threading and meandering over the sandy plains and forming islands covered in large trees, providing ideal fishing grounds for the owls. Even so, each pair of fishing owls needs a large territory, and thus over the entirety of Southern Africa there may be only about 500 pairs of owls, at most.

It is mainly on account of its rarity that this owl is seldom seen. If you know where to find it, you have a good chance of glimpsing it. The region we went, is known to support a few of the owls. By day, the owl roosts and rests in a leafy tree. It can be very well concealed, but if you're fortunate, you might glimpse the bright rufous of its plumage through a gap in the leaves and branches. If disturbed, the owl will fly out from its perch, often roosting out in the open from where it can see you, and you can see it as well. Where we found the owls, however, there were so many big trees that the owls remained fairly well-concealed, even though some of the photographers managed to get a few good shots.

In its general behaviour, this owl resembles the others in being nocturnal. It perches on large branches overhanging a quiet pool or stretch of backwater along the river. Occasionally, the owl will fish by standing on the riverbank and wading into the water. Its large, dark brown eyes furnish it with keen vision, and it watches for ripples on the water surface to betray its prey. It may listen for the grinding calls of squeakers, small fish that make sounds by grating their fin bones together. Once it has found and targeted a fish, it swoops down, at the last moment throwing its wings backward, to keep them clear of the water, while thrusting its legs and feet forward. It grasps the fish firmly with its spiky-soled feet, and flies back to its perch to feed. A fishing owl can catch fish up to 2 kg/4.4 lb in weight, which is almost as heavy as itself. But most of the time it sticks to fish about a tenth of this weight. It favours species like catfish and African pike, and one we saw, was clutching a segment showing the tell-tale speckles on its sides of a Tiger Fish, Hydrocynus vittatus. I portrayed this in my drawing. Tim Liversedge, who studied these owls in the Okavango, reports that they seem to favour the fishes' heads, even discarding the fleshy bodies on occasion! They regurgitate the indigestible parts of their food as pellets, but these rapidly disintegrate, containing no hairs or feathers to bind them together. Apart from fish, the owls sometimes catch frogs, crabs or freshwater mussels. They've been said to catch mammals and birds, but this hasn't been confirmed. There is one record of a fishing owl catching a baby crocodile.

The call of Pel's fishing owl is rather spooky. Unlike other owls, who start calling after dusk, these owls typically wait until midnight before they call. Their call is a deep hooting that resonates through the deep dark under the night-blanketed forest. The voice of the female is higher-pitched, even though she is generally bigger in body than the male. The male and female calls together during the breeding season in duets lasting up to fifteen minutes. The owls have several other calls as well, the juveniles especially having various cheeps, trills, wails and hoots. The female, if she thinks her chicks are threatened, will try to attract the attention of the predator with a high-pitched trill. She will walk along a branch, swaying and spreading her wings, and then fall to the undergrowth and flop around, feigning injury, to distract it. Sometimes the male also performs a distraction display. The only serious predators of the Pel's fishing owl are the Giant Eagle Owl and the African Fish Eagle.

The breeding season for Pel's fishing owls tends to be in the summer, or early autumn, when water levels are dropping and more fish can be expected to be trapped in small, drying pools. They nest in large cavities in trees – another reason they're dependent on pristine riverine forest. Although the female usually lays two eggs, invariably only one chick survives. The female incubates while the male fishes and brings her food; the same happens once the chick hatches, the female staying with it as the male provisions them. The chicks leaves the nest at about ten weeks, and stays with its parents for several months longer. Likely, it needs a bit of time to learn how to fish. Life is tough for young owls and many of them starve. It achieves adulthood at around 10 months. Because of the long time needed for chicks to mature, these owls often breed only every second year.

At present, Pel's fishing owl can be considered at risk. The greatest threat to it is habitat destruction, through the felling of the large riverine trees it depends on. Dam building, water pollution, and overfishing also threaten them. At present, they still have a large overall population and seem to be stable, but we need to keep watching them.

Willem

05.02.24 Front Page

Back Issue Page