**This is a public service announcement on behalf of all animals**

Have you ever turned on your spotlight and looked directly into its beam? No! Because it blinds you right……..?

Using white spotlights at night are as intrusive and disruptive to animals going about their business as the paparazzi are to the royal family! 

The scientific stuff…..

ALL eyes are made up of rods and cones and this affects how all of us see in various light situations. When we use spotlights on animals at night we need to be respectful of the effects it may have on the animals we are viewing.

Rods are responsible for vision at low light levels (scotopic vision). They do not mediate colour vision and have a low spacial sharpness.  

Cones are active at higher light levels (photopic vision) are capable of colour vision and are responsible for high spacial sharpness. 

Light levels at which both are operational are called mesopic. 

Most mammals other than primates have a layer of reflective crystals at the back of the eyeball called tapetum lucidum which reflects light back onto the retina, thus making twice the amount of light available and allowing the animal to see better in the dark. Most also have more rods and fewer cones. 

So what on earth does this all mean?

*During daylight hours cones in the retina allow colours to be perceived. 

*In the hours of darkness the rods mediate vision and colour vision is sacrificed for light gathering and light sensitivity. 

*At dusk and dawn the retina is in a state of flux between rod and cone vision and in this stage both colour and light sensitive vision is NOT very good! 

*As conditions move towards darkness, the eyes adjust to lowered light conditions and become fully ‘dark adapted’ after roughly 30 to 40 minutes. A risky time….

*More scientific stuff – It is at this point that a light sensitive chemical know as rhodopsin (a protein essential for vision in low light) also known as visual purple, has accumulated in the rod cells and any exposure to a bright light (like our spotlights), will start converting it back to vitamin A from which it originates. 

*If the light exposure is quick, the rhodopsin is not fully converted and reverts back to its original state fairly quickly – think about what happens when we look into a bright light and for several seconds you see an ‘imprint’ of that light as you blink, even though you are no longer looking into it. 

*If the light exposure is longer than half a minute, the rhodopsin is completely broken down and the adaption to the dark conditions has to begin all over again taking another 30 to 40 minutes. 

Heard of the expression ‘a deer in the headlights’? 

Diurnal animals (animals that are active during the day) such as antelope have excellent night vision as an adaptation to escaping potential predation. Exposure to a white spotlight, essentially dazzles and disorientates and this puts them at an unnecessary risk. 

It is therefore critical that a red or blue filter is used when shining on animals that are active at night. The majority of animals encountered at night are ‘blind’ to infrared light rays and thus there is no chance of blinding them or exposing them unethically to potential predators.

The animals thank you for taking the time to read this 

📸  taken at Nambiti Game Reserve