In the tropical and semi-tropical forests of peninsular India, the spring season is not very eminent. The mild winters gradually make their way to the hot summers. Yet, in the forests of Kanha, there are tell-tale signs everywhere that the winter is over, and the short season of spring is here. Insects have suddenly become active and several resident birds are now busy courting, mating or making a nest, or doing all of these things simultaneously.
But the most conspicuous signs of the arrival of the spring are given by the trees of Kanha. Sporting green leaves almost throughout the year, several evergreen trees have now slowly and quietly changed their attire to a red one. These are young leaves, and the red costume is only a temporary one; for these leaves will change their colours into various shades of green almost as discreetly as they appeared.
But why are these young leaves red? Surely these young leaves have to carry on the function of photosynthesis, and for this they need to be green. But there are reasons for these trees to keep the young leaves red. Young leaves appear red because of a pigment called anthocyanin. This pigment protects the vulnerable young leaves from the harmful radiation of the sun, till the time they are ready to cope with it. Red colour also makes the young leaves look unpalatable to herbivorous animals such as deer and monkeys. Anthocyanin also makes the leaves indigestible for defoliating insects, such as aphids. These gluttonous insects would otherwise devour the tender leaves of the tree as soon as they appear, which could be potentially lethal for the tree.
Several trees, including the Saal (Shorea robusta), Mahua (Madhuca longifolia) and Mango (Mangifera indica) – some of the most common trees in Kanha, produce red leaves. But the red colour remains only for a short while, and the leaves of these trees turn into hues of green quickly. But the most magnificent of red is seen on the leaves of the Kusum (Schleichera oleosa) trees. Passing under a corridor shaded by Kusum trees at this time of the year is simply a sight to behold!
Naturalist, Singinawa Jungle Lodge