When we moved to the Algarve 18 years ago we did not expect to find such an exciting variety of wildlife in our garden. Among the exotic bats, terrapins, crayfish, geckos and birds we were thrilled to find we had chameleons.
Belonging to the lizard family, their name derives from the Greek words for ‘on the ground’ and ‘lion’. There are over 200 types of chameleons (the smallest is 15mm and the largest 69cm) with half the world’s species living in Madagascar and many being unique to the island. The Algarvean species has tones of green, yellow and brown and is known as the Common Chameleon.
Chameleons were first officially recorded in Portugal in 1945 and genetic testing indicates they originated from Morocco and so may have been brought over with traders. Portugal is the northern limit of the chameleon’s distribution but they are also found in Spain, Cyprus, Malta, Africa and Southern Asia.
During September and October, we usually find chameleons ambling along fences or running across the garden because the females come down from the trees to lay between six and 24 eggs in the ground. The eggs take between six months to two years to hatch and adorable miniatures of the adults are born completely independent. They are solitary animals usually living in woodlands or dune vegetation, usually matching their skin colouring to their environment.
Chameleons are protected by European law which states that they cannot be disturbed nor have their natural environments destroyed. Last year the demolition of illegal houses on Faro’s Farol Island was thwarted as the courts ruled that this would be detrimental to the chameleons living in the area. However, subsequent verdicts reversed the decision and the islander’s battle to save their homes continues despite the chameleon’s presence.
Chameleons are extraordinary reptiles due to their distinctive appearance and attributes. They have scaly skins, crests or horns on their heads and a curled tail which is used to grip and balance. Although they have no ears, chameleons are not deaf and can detect certain sound frequencies.
Their eyes see ultraviolet light and move independently of each other so they can look in two different directions at the same time with a 360 degree arc of vision. I find this disconcerting! Able to see prey 5-10 meters away, they live on small insects, spiders, lizards and sometimes birds.
It is their ballistic projectile tongues, which are 1.5-2 times the length of their body, that enable them to catch prey in 0.07 seconds having launched their tongue at accelerations exceeding 41 g! As the ball of muscle hits the prey, it creates a suction cup retracting it straight into the mouth.
When threatened, chameleons swell up and darken, opening their mouths to hiss aggressively. However, they are harmless and, unfortunately, easily caught by people wanting them as pets. They can live up to 10 years in captivity but are hard to keep healthy.
I think these creatures are mesmerising to watch as they move one limb at a time to walk in slow jerky movements although they can run rather fast on the ground. It looks like they have two digits on each foot but these are five separate toes grouped into sets of two and three toes that act like tongs to grasp branches.
It is, however, the chameleon’s ability to change colour that is most fascinating. They come in a variety of colours which can be modified due to their special layers of skin cells, called chromatophores, which contain colour pigments. The nervous system or blood stream sends signals to the cells discharging them to mix the pigments together to alter the colours, just like mixing paint!
Did you know that not all chameleon species are able to change colour? Those that can create patterns with yellow, pink, blue, orange, red, green, black, brown, turquoise and even purple. Although it was believed that chameleons changed colour to camouflage themselves, research has now shown that changes are due to variations in light, temperature, stress and mood, and are also used to communicate with other chameleons.
Scientists have long tried to replicate the chameleon’s ability to change colour developing thermochromic substances which can alter shape, state or colour due to temperature variations. We have t-shirts, mugs with secret messages, sunglasses, strip thermometers and even nail polish.
Mood rings were created in 1975 using liquid crystals and hypercolour clothing using leuco dyes appeared in 1991. The clothes were a huge hit with sales over 50 million dollars in a few months. Unfortunately, mismanagement coupled with falling sales as the t-shirts lost their ‘magic’ when washed led to bankruptcy in 1992 and attempts to revive the technique in the early 2000s failed.
So, will we ever be able to copy the chameleon and instantly alter our appearance according to our environment or mood?
At the University of Bristol, in studying colour-changing squids and fish, scientists have succeeded in creating a colour-changing substance that the military are interested in for self-camouflaging clothes. Also, researchers at the University of California have developed a thin material that changes colour when flexed. They hope the new “chameleon skin” could be used in construction to indicate structural fatigue or for medical purposes using ‘smart bandages’ as sensors to detect the presence of infections.
Furthermore, exciting times are ahead as new Ebb technology developed recently in the US has produced a colour-changing thread which changes hue in response to electrical stimulation and may soon be used to produce smart clothes as tactile displays that could change according to our moods. Would you wear them? Personally I do not want people knowing how I am feeling just because my clothes suddenly change colour, although my partner thinks this would be useful to gauge my moods!
Look out for the amazing camouflaged chameleons in your garden.
So now you know!
By Isobel Costa
Isobel Costa works full time and lives on a farm with a variety of pet animals! In her spare time, she enjoys photography, researching and writing.