Getting to know The Owls of South Africa
By S. M. Malematja, Curator Ornithology, DITSONG: National Museum of Natural History
Owls are often misunderstood and labelled as mysterious creatures of the night. Owls are generally identified by their nocturnal activity patterns, camouflage plumage, upright posture, large eyes and freaky ability to rotate their heads by as much as 270 degrees. They are highly stigmatised within African communities and are believed to be a bad omen relating to witchcraft practices. The lack of knowledge of owls has contributed to multiple conservation challenges. The aim of this article is to educate the public about the owls of South Africa, by highlighting their significance. Secondly, to eliminate unfounded stigmas surrounding owls in order to improve the current conservation efforts of owls.
There are two major groups of owls, namely Tyto owls and Typical owls. Tyto owls have a distinctive heart-shaped facial appearance, long pointed wings and oval-shaped eggs. Typical owls are round headed and have short rounded wings and round eggs. South Africa in particular, has twelve owl species, two of which belong to the Tyto grouping. The South African owl species are unique and diverse. They are spread throughout the country and occupy various types of habitats.
Figure 1: Typical owl. DITSONG: National Museum of Natural History Ornithology collection.
Figure 2: Tyto owl. DITSONG: National Museum of Natural History collection..
Figure 3: Skull of Tyto owl on the left and Typical owl on the right. Note the difference in facial structure. Tyto owls have an oval skull shape, whereas Typical owls have a round skull. DITSONG: National Museum of Natural History collection.
Habitat and distribution
Owls do not usually build nests, they identify suitable nesting sites, such as tree burrows or abandoned bird nests in their preferred environment, and mark these sites as territories. Habitat preference is species specific – some common habitats include, grassland areas, wetlands, woodlands and urban areas. The Cape eagle-owl, is known to live specifically in mountainous areas such as rocky outcrops and cliffs, whilst some species such as the spotted eagle-owl are able to tolerate a variety of habitats from urban areas to forest areas.
Owls are birds of prey, they hunt and feed on smaller animals such as small rodents, other bird species, small reptiles and insects. They do not usually drink water, but obtain water from their diet. Their physiology is specifically adapted for nocturnal hunting. Their claws are strong and curved, in order to penetrate the skin of prey to ensure a tight grip. The beak is hooked at the tip, to assist in tearing prey. Owls have large eyes. However, they are believed to perceive images that appear grainy and lacking in colour. Owls have the best vision in comparison to other birds. Owls have excellent hearing, that aid in detecting movement of prey. Once prey is detected, owls will turn their heads towards the direction of the prey, and follow by flight towards that direction. Their feathers are adapted for silent flight, which largely contributes to their hunting success. After ingestion and digestion, indigestible food items such as feathers and bones collect at the bottom of the stomach, and later regurgitated, or vomited.
Figure 4: Large flight feathers adapted for silent flight.
Mating and breeding
Like many bird species, owls coincide their breeding seasons with food security. Owls are monogamous. The correct time for copulation between mating pairs is recognized when both male and female exceed their usual hunting success as this signifies food abundance. During breeding season, a male identifies and claims a nesting site. The male will thereafter attract a mating partner by mating calls and display flights. Once a mating partner is acknowledged, courtship begins. The pair engage in courtship activities such as nibbling, cuddling and mock copulation. The pair will copulate and the female will lay and incubate the eggs, while the male hunts for prey to bring back to the nest. Smaller owls generally lay more eggs than large owls. Owls are clean birds; during breeding season the female owl defecates at the edge of the nest. After hatching she eats the remaining egg shells and trains the nestlings to defecate their droppings at the edge of the nest in order to keep the nest area clean.
Figure 5: An owl egg. DITSONG: National Museum of Cultural History.
Benefits of having owls in the environment
Most owls are predators, they feed on smaller animals such as rodents, therefore they act as natural pest control agents. In recent years, owls have been deployed to the famous township of Alexandra in Johannesburg, in order to eradicate rodent infestation in that area. This decision by the City of Johannesburg, highlights the importance and usefulness of owls in the environment.
Two out of the twelve South African species of owls are currently categorized as vulnerable and endangered species by the International Union for Conservation of Nature (ICUN). The African grass owl is ICUN vulnerable, mainly due to the degradation of their environment. The Pel’s fishing owl is ICUN categorized as endangered, also due to habitat degradation, as well as pollution. The Owl Rescue Centre based in Hartbeespoort, North West Province, is one of the multiple conservation efforts of South African owls. The centre rehabilitates owls that have been injured, are sick, poisoned or orphaned and then release them back into their natural environment. This is a great conservation effort, however, it is important to highlight that the best conservation effort is one where the entire public engage in actively conserving owls. The best way to start is to gain as much knowledge as possible surrounding these birds. DITSONG: National Museum of Natural History is home to a comprehensive collection of owls comprised of owl skins, eggs and skeletons used for research purposes. There is also an owl exhibition in the Museum’s Austin Roberts bird hall. The exhibition displays the diversity of South Africa’s owl species.
Figure 6: Owl exhibition at the DITSONG: National Museum of Natural History.