Part II of this nocturnal series sees us focus on a family of birds that I truly find fascinating; the owls. They have a presence, unlike any other bird, striking pure and genuine excitement when one is seen. Taking even the briefest moment to appreciate these amazing specialists of the night is always worthwhile.
At Londolozi, we have the honour of seeing many different species of owls. In fact, out of all the twelve species of owls that occur in Southern Africa, only the Cape Eagle Owl has not been recorded at Londolozi. That is an incredible record, and yes, there was a record of a Pel’s Fishing Owl here many years ago.
Pel’s fishing owl is a large species of owl found in Africa. Although it is an incredibly rare and unlikely bird to see at Londolozi, it has been seen here many years ago.
Owls are synonymous with nocturnal activity and have developed many adaptations to help them be so successful. The Pearl Spotted Owlet and the Barred Owlet are two of the smaller birds in the owl family that are, in fact, not nocturnal. They are voracious daytime predators of other small birds.
Barred Owlets along with the Pearl Spotted Owlet are both crepuscular. Meaning they are more active during dawn and dusk.
So what makes owls so successful in their niche of being nocturnal aerial predators? Well, it cannot be pinpointed to one factor or character but rather to many different aspects in combination.
Silent flight
Owls have specialised flight feathers that allow them to swoop towards their prey in complete silence. These feathers alter the air currents that flow over the wings, resulting in a remarkable reduction in noise as the upper and lower currents merge at the wing’s specialised trailing edges.
Incredible hearing
Owls have acute hearing. Their ear cavities are offset, this allows a split-second difference in the reception of sound in each ear. This unique way of hearing allows them to pinpoint sounds made by potential prey, a key feature when hunting in complete darkness. An owl’s hearing is so advanced, that they can almost exclusively hunt just by sound.
A Spotted Eagle Owl listens carefully for potential hunting opportunities.
Night vision
Owls’ eyes are incredibly special. Their eyes are conical and set deep within their sockets. These cone-like eyes that are fixed in the socket mean that although they have binocular vision, the owl must physically turn its head in order to see things around it. Being able to turn their head 270 degrees helps them in this aspect. They are unable to move their eyes independently of the head.
The cornea and pupil of an owl are significantly larger than ours. Meaning that their rod cells heavily outweigh the number of cone cells. Because of this, they have monochrome vision but can make use of the smallest amount of light in the darkest of evenings.
A Verreaux’s Eagle Owl perched in a dead leadwood tree, looking for potential prey moving around at the base of the tree.
Owls are remarkable birds that are the masters of the night. They have all the tools to continue to dominate the in darkness. Next time you see an owl, remember the unique features they possess in order to continue thriving in difficult conditions.
Patrick Grealy
Source link