There’s a lot of beauty in the ordinary things. Isn’t that the point?
After reading an incredible book by Jackie Higgins: Sentient, I have found myself delving deeper into what that means for us in our daily lives, and while out on game drive my mind often wanders to how that translates to the animals around us. In my previous blog, I spoke about what it means to be sentient, and how senses and sentient beings are inextricably linked. As humans, we can observe how familiarity dulls our senses. So let’s look at arguably our most vital, and complex sense: Sight.
Ranger Kate Arthur explains the structural adaptations of eyes in nature in her blog – Structural Adaptations: Eyes. While keeping it simple, sight starts when photos of light or little packets of energy so small, bounce off an object and enter the pupil of our eye, travel through to the back of the eyeball and reach the photoreceptors of the retina. Here they hit an opsin. This sets off a cascade of chemical reactions that ends in an electrical spark. This spark becomes a signal that shoots down nerves to the brain and the external world becomes something we can perceive internally.
The Lowveld landscape: a continuation of crests with a granitic rocky outcrop in the distance
We are all guilty of underappreciating – and underestimating – our sensory powers.
If looks could kill.
Scientists still have little idea how nerve cells can give rise to the inner experience: how the tangible becomes intangible. Yet, this astonishing transformation plays out with the mundane, microsecond repetition.
The calculus of colour perception across the animal kingdom is relatively straightforward; species see different rainbows of colour depending on how many colour receptors they have. Monochromats with just one type of cone – seals and wales for example – are colour-blind and see the world in one hundred shades of grey.
Dichromats with two – a list that contains nearly all mammals from Aardvarks to Zebra – see a reduced rainbow. Take a Leopard for example, the two colour-detecting cones let them see blue-violet and yellow-green wavelengths but not red-orange. Meaning they mainly see things in shades of yellow, grey, and blue tinges (but some researchers think that cats may also notice some shades of green). If you’ve ever wondered How Leopards See the World, read Robyn Morrison’s amazing blog about it.
The Three Rivers Young Male glances up into the canopy of the tree he had just stashed his kill. Perhaps planning a route in his head.
Then there are the rare mammalian trichromats, us. Kept only company with baboons and great apes, our sight is far from ordinary. Most vision experts agree that the average and unremarkable human eye can probably see as many as several million shades of colour.
An early afternoon thunderstorm this last week left behind the most incredible light as it passed. We happen to find ourselves with the Birmingham Male under this golden sky accompanied by a glowing rainbow.
I also want to divert briefly and mention that I’ve only really spoken about colour vision here, not the so-called strength of vision. Take birds of prey for example. They have excellent long-distance vision, but eagles and vultures stand out. They can see clearly about eight times as far as humans can, meaning roughly, a vulture can see an 8cm object on the ground from 1km up in the sky!
The Hooded Vulture is at the bottom of the vulture hierarchy at carcasses yet has some of the most incredible long-distance vision. Often leading it to be the first arriving vulture at a kill.
Our human brains compensate for our eyes’ shortcomings, allowing us to perceive more colour in the world than our mammalian counterparts. But, take a moment. Look up from this screen and open your eyes to your surroundings. Let the beauty of the world around you of the incredible gift of sight.
An avid nature and science reader, this book sounds like one I’d love! I just added it to my Goodreads list. 🙂 I appreciated the example you gave of birds of prey being able to see an 8 cm object 1 km up in the sky. That really paints a picture of the difference between their distance vision and ours.
I was recently in a hot-air balloon slightly higher than 1 km off the ground, and it was difficult to determine if the plants below were merely shrubs or actual trees. My depth perception and perspective were all off. Raptors must not have that same problem. As a human, the thought of having that sort of visual acuity seems overwhelming. How wonderful that we’re all made perfectly just as we are.
Great article , Keagan. The wonderful pictures in all those colors or also black and white photography always remind us, how wonderful it is to be able to enjoy such a colorful world.
I love the photos here, especially the one of the baboon.
Thanks Keagan for your interesting story on senses and sight. We do take our senses for advantage and should appreciate each sense 100%. Animals and birds have an alarming eyesight, as you explained about the eagles and vultures. Eyesight is one of the most important senses for both animals and humans.
Keagan, interesting blog about sight in some of the animals of Londolozi. The sense of sight is so important to so many of us in the world it is hard to imagine not having it available.
Thanks Keagan for continuing the educational articles that you and your team have provided to us over the past couple of years. During a game drive I find my senses heightened, especially sight and sound. I’m grateful that I am able to experience the myriad of colors found throughout nature, no matter where they may be found. It was especially interesting to read that some sea creatures only see in gray, missing out on seeing all the vibrant colors of so many fish
Hi Keagan, Duncan recently lent me a book called “An Immense World” by Ed Young. It deals in great detail with the sensory systems of pretty much all living things in general and is quite easily the most informative book I have ever attempted to read. However, be warned and expect an information overload. I have had to retire the book to the “pick up again pile” as I simply can no longer absorb the facts. Naturally visual acuity is covered and an interesting fact is that a lions visual acuity is approx 20% of an average human and scientists postulate that from more than 80 meters a zebra would look like a donkey, though of course it would still smell like a zebra. At the very pinnacle of experimental tests sits the Australian Wedge-tailed Eagle which can spot a rat from a mile away. I will be at Londos (babysitting) for a while from Wednesday next week and will try to look you up for a chat. Ian
Very cool post Keagan!