Home Photography Photofeature A Riot Of Red

A Riot Of Red

A Riot Of Red

Debates rage among experts as to why colours evolved and how they affect animal behaviour. We do know, however, that colour vision is the result of intricate wiring in the brains of some animals that enables them to tell objects apart, based on how light emanating from the objects stimulates in-built receptors.

But can and do plants actually use colour to determine the behaviour of animals? In the case of some fruiting plants, this seems plausible and points to the possibility of the co-evolution of colour pigmentation in plants and colour perception in animals.

It is, for instance, advantageous to plants to discourage animals from eating their fruit till the seeds have developed internally and are ready for dispersal. This is probably why some fruits change from green to red when they ripen. From the point of view of the animal, of course, the technology is simple: when objects reflect radiations of a longer wavelength, they could deliver a ‘sense’ of… the colour red!

Rose finch Carpodacus erythrinus

Nirmal Kaur Photo: Nirmal Kaur.

The male is more attractive than the female. In the breeding season, the colours are more vivid suggesting their purpose. Rose finches feed on seeds, berries, flowers and nectar. They breed in the Himalayan region from Garhwal to East Assam and winter in the subcontinent. On arrival in India, the birds are in fresh plumage and the male changes considerably in appearance – less rosy and more red.

Silk cotton bugs Dysdercus cingulatus

Anish Andheria Photo: Anish Andheria.

These silk cotton bug nymphs, seen feeding here, are found in large numbers in forest areas. The adults are red and black. The bright colouration serves to warn birds of the bug’s inedibility.

Millipede Class Diplopoda

T.N.A. Perumal Photo: T.N.A. Perumal.

Millipedes are non-toxic, but they may be using the colour red to mimic poisonous centipedes. Millipedes have a hard exoskeleton and many jointed legs and thrive in moist habitats under rocks, rotting logs and leaf debris.

Trees or plants with red flowers are particularly attractive to birds and insects. Many insects, on the other hand, use shades of red to advertise their unpalatability, warning off potential predators. And for every one of these examples whose function is known, there are thousands more that we can only guess.

Devil’s eye seeds Abrus precatorius

Anish Andheria Photo: Anish Andheria.

Crab-eyed creepers are slender, perennial climbers seen in thickets, usually around the edges of deciduous forests. The seeds are bright scarlet in colour with a smooth glossy texture and a jet-black patch on top. They are toxic and used only for ornamental purposes. The dried leaves are sometimes eaten with paan.

Blister beetle Family Meloidae

Otto Pfister
Photo: Otto Pfister.

Elongated cyclindrical insects, they feed on the flowers and foliage of various plants. The common Indian genera Mylabris, Lytta, Psalydolytta and Epicauta use red as a warning colouration. The adults feed on plants and the larvae are predacious or parasitic and feed on the eggs of bees and grasshoppers. They contain the toxic chemical cantharidin that can cause human skin to blister.

Land crab Paratelphusa sp.

Hira Punjabi Photo: Hira Punjabi.

Common in and around freshwater streams, ponds and swamps, land crabs burrow into the ground or stream banks. There are several species of land crabs in India, with colours ranging from the dark red seen here to brown and black. Once again, the red could be a warning to scare off predators, but this has not been conclusively established.

At one time, it was believed that the ability to see red, green and blue light (trichromatic vision) was an evolutionary tool to help primates select ripe fruit from trees. New research suggests that red and green vision may also have helped our ancestors to select tastier, young leaves on trees.

Several lifeforms, including humans and other primates, fish, amphibians and birds are able to see colour. But colour vision for most of these species is relatively primitive form, limited to blue and yellow light. Only a small group of primates can see the full range of colours from red to green as well as blue-yellow.

Golden flying snake Chrysopelea ornata

Anish Andheria
Photo: Anish Andheria.

These snakes are able to glide from tree to tree by pulling their ventrals inward and forming a parachute. Golden flying snakes are arboreal, diurnal and mainly feed on lizards. Perhaps, the red colouration is an evolutionary tool to confuse predators into mistaking them for the somewhat similar-looking, much more poisonous, coral snake.

Zingiber Family Zingiberaceae

T.N.A. Perumal Photo: T.N.A. Perumal.

This herb has a red, tuberous stem. The bright-red structure in the image is not the flower but the plant’s bracts (flower-like leaf structures). It is common in forest clearings at elevations. Also note the land crab in the image.

Forest calotes Calotes rouxii

Anish Andheria Photo: Anish Andheria.

Male forest calotes transform themselves into a brilliant orange and black during the summer breeding season, to attract the more drab females and possibly to drive away rival males. However, they can change to wood-brown at the slightest hint of danger.

Fly agaric mushroom Amanita muscaria

T.N.A. Perumal Photo: T.N.A. Perumal.

Summer bloomers, these crimson mushrooms are easily identified by their bright red caps and rings on their stems. They contain the toxic, alkaloid muscimole that possesses hallucinogenic properties and is potentially fatal, if consumed.

Sanctuary Asia, VoL. XXII. No. 2, April 2002.

 
 
 

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