Ranthambhore tiger reserve, with its sub-tropical dry climate, has three very well defined seasons – summers, winters and monsoons.
Summers start during the end of March and last through the months of April, May and June. During this season the days are very hot and dry, while the nights are warm. During May and June the maximum day temperature regularly cross 40 degrees Centigrade and the minimum night temperature still hovers around or above 30 degrees Centigrade. During the day, there are strong hot and dry winds, known as loo. In the dry summers of Rajasthan, it is very easy to dehydrate and water resources are at a premium.
The vegetation on the plateaus and hill tops dry out first, usually before the end of winters. There areas are heavily used by wild ungulates during the monsoons and winters. By the end of winters most of the waterholes on the plateaus and hill tops dry out and there is little, if any, grazing left for the ungulates. As a result most of the ungulates come down to the valleys and avoid the heights until it rains again. Gradually the vegetation starts drying out all over the reserve, except along the few waterholes that never dry out. Anogeissus pendula or Dhok – the dominant tree of the reserve shed by mid March and stay barren till the next rains.
By the middle of March summers are well established and most of the smaller waterholes start shrinking. This is most visible in the area of the lakes. Cynadon dactylon – a short green grass – flourishes in the ground left behind by the receding shoreline of the lakes and Spotted deer love to feed on these. The Sambar deer are in turn attracted to the lakes by the aquatic vegetation. By and large, grazing and water availability are in short supply.
By the end of March the only patches of green that can be seen in the reserve are along the permanent waterholes. There are few species of trees that do add some color to the reserve. These include the brilliant red flowers of the “Flame of the Forest” (Butea monosperma), the yellow flowers of Amaltas (Cassia fistula), green leaves of a few Acacia, Ziziphus and Ficus species. Langur monkeys are often seen feeding on these trees and herds of deer follow the monkeys, to feed on the leaves and fruits that are dropped by the playful monkeys.
The few remaining waterholes and green trees are like an oasis for most of the wildlife. There are large areas of the reserve that are almost devoid of wildlife. Which tends to concentrate around the existing waterholes. Birds that visit the reserve during winters return to their summer nesting grounds, while the summer visitors like Golden Oriole, Crested Buntings, Paradise Flycatchers and Indian Pitta migrate into the reserve. A large number of reptiles suddenly become visible. Most of the male deer loose their antlers and start growing new ones. They also loose their winter coat and start looking very shabby and under nourished. Summers in Ranthambhore are a time of shortages and hardships for most animals and birds.
Tiger sightings become relatively easier as finding tigers become easy. Tiger need a lot of water to drink and cool off and they tend to stay close to waterholes in the summers. Besides, since most of the prey is concentrated around the few remaining waterholes, the predators tend to do the same.