Owls are my favourite birds. I’m sure it has a lot to do with the characters that represented them in books I read when I was young, but years later they continue to excite me whenever I encounter them out in the bush.
Out of all the species that occur in Southern Africa, only the Cape Eagle Owl has never been recorded at Londolozi, so we’re fairly lucky with the owls we see (apart from the pair of barn owls that have taken up residence in a tree near my house; they haven’t let us sleep for over a month now with their all-night shrieking!).
Being almost exclusively nocturnal as a group, owls have clearly had to adapt to be able to hunt their prey effectively in the dark, and while they are famous for their night-vision, this isn’t even what makes them such deadly predators. Well it is in part, but it’s more a combination of factors.
Not all owls are exclusively nocturnal. Pearl-spotted owlets are far more crepuscular, and often encountered in the day. Photograph by Andrea Campbell
Firstly, they can glide in towards their prey in almost complete silence. Specialised flight feathers alter the air currents flowing over their wings, resulting in a tremendous reduction in noise as the upper- and lower currents merge at the wings’ trailing edges.
The trailing edge of an owl feather, showing the uneven fibres that help merge air currents more smoothly, reducing sound. Photo courtesy of asknature.org
Flying in silence, as well as giving no warning to their prey of their approach, also allows the owl to hear a lot better, and this is apparently how they really lock in on their prey. Owls’ ear cavities are offset on the side of their skulls – unlike ours which are symmetrically placed – allowing for a more accurate assessment of where the noise of their prey is coming from, and they can supposedly hunt almost exclusively by sound.
How that barn owl pair near my house manages this when they seem to be shrieking from sunset to sunrise is beyond me!
Their eyes are the final piece of the puzzle, and are pretty special in their own right:
Unlike our eyes, which are round and able to swivel in their sockets as a result, owl eyes are more conical, and set within deep sockets. They are firmly fixed in place, meaning the owl has to physically turn its head in order to see things off to the side. This might sound like a disadvantage, but when you consider that owls can turn their heads 270 degrees in either direction (a 540 degree arc!) it doesn’t sound like too bad a compromise.
The cornea and pupil of an owl’s eye are significantly larger than our own, as is the retina. Rod cells – the truly light-sensitive ones – are in far higher abundance than cones – the ones that detect colour – so owls generally have monochrome vision but are able to make use of the smallest amount of light available.
A scops owl, Londolozi’s smallest. Photograph by Alex Jordan
Owls occupy what is essentially a very difficult niche; that of a predatory night-bird. Their family has managed to overcome the obstacles associated with the niche in some of the most remarkable ways, rendering them incredibly efficient birds.
If the barn owl pair could just lower their volume a tiny bit in the coming weeks, I think there are more than a few of us who would be grateful for it, and we can then get back to appreciating the family properly!
Owls have got to be among my favourite birds, especially the Verreaux’s (which I’ve seen twice)! It’s quite impressive that you have all but one of the Southern African owl species on Londolozi, I’m guessing you’ve seen Pels there before?
And I wouldn’t say no to having barn owls as neighbours (even if they are annoying loud, which I know from experience)!
And a very interesting read too!
Love these informative blogs. Interesting facts about owls. We have got wood owls in the garden and luckily it is a lovely gentle sound in the night.
The scops owl has to be my favourite, though I did find a large tawny owl in my garden at midnight last week.
It had taken up residence over the framework of my fishpond.
Suspect it was waiting for a mouse or similar
Neil and I just love owls. However, the stories in children’s books are always about the “old wise owl”. We have been a couple of times to a place in Woodmead, Johannesburg, called “Free Me” to hand in an injured small animal (wild) or a bird in need of some TLC from people who know what they are doing. When I was last there we watched a lecture by the ladies who run it on birds of prey. They had an owl and were trying to teach him to fly. Then they flattened all future thoughts of mine about “wise old owls” by saying, in their experience, owls were the dimmest birds ever! Other birds were much quicker to understand what they were supposed to do but the owls took forever to learn anything at all! However – the ladies admitted that they are VERY good at just being owls!
Thought I would just pop that in. Wendy M
Hi again James. Just a P.S. We are so surprised that Londolozi doesn’t have as yet any Cape Eagle Owls. Game farms in the Waterberg Mountains have them. Quite often when on late afternoon / evening game drives we have seen them. We live in Windsor East / border of Robin Hills in Randburg. We live on a North facing hill and have 2 resident Cape Eagle Owls. They seem to be male and female and we have often seen them talking to each other silhouetted on a chimney. They would have a fabulous view over the valley. We can see the Hartebeestpoor Dam hills very clearly in Summer particularly – about 53 kms away. On clear days we can also see the Voortrekker Monument too from our bedroom / lounge / balcony. So that will tell you that the owls here would have a great view over the trees and gardens and would be able to pin down any small mammal / bird with their incredible eyes and ears. Warm regards to you all at Londolozi. You all do a fantastic job! Wendy M AGAIN.
Whether twisting their heads or cocking from side to side, owls and owlets are extraordinary to see and watch. With their keen senses and silent soaring they obviously are healthy and self sufficient. The silent soaring bit hasn’t made me very happy in past months as a recently fledged juvie Eagle was knocked off it’s nest branch during the night and severely injured when it fell to the ground. Thousands gasped while watching it occur on the night cam. This particular nest has been located for 10 years by the same mated pair of Eagles. Perhaps this was a defensive move by the Owl who might have nested nearby -or- perhaps it was just being ornery. Regardless, that’s Nature for you. Speaking of Nature, I hope your pair of Owls stop their shrieking or you may need to invest in a pair of ear plugs! Lol.
I know what you mean by the nightly shrieking of the barn owls. We have them here in the Bay Area and a couple take up residence in a tall pine tree not far from my bedroom window. Needless to say, sometimes sleep is at a premium when they’re around. Interesting blog!!
Come on, James, what about serious earplugs? Not just cotton wool, but noise stoppers!