recorded to use tools. By balancing sticks and branches on their heads, they lure birds that are looking for nesting material. This strategy is particularly effective during the nesting season. Reproduction Female muggers obtain sexual maturity at a body length of around at the age of about 6.5 years, and males at around body length. The reproduction cycle starts earliest in November at the onset of the cold season with courtship and mating. Between February and June, females dig deep holes for nesting between away from the waterside. They lay up to two clutches with 8 –46 eggs each. Eggs weigh on average. Laying of one clutch usually takes less than half an hour. Thereafter, females scrape sand over the nest to close it. Males have been observed to assist females in digging and protecting nest sites. Hatching season is two months later, between April and June in south India, and in Sri Lanka between August and September. Then females excavate the young, pick them up in their snouts and take them to the water. Both females and males protect the young for up to one year. Healthy hatchlings develop at a temperature range of . Sex ratio of hatched eggs depends on incubation temperature and exposure of nests to sunshine. Only females develop at constant temperatures of , and only males at . Percentage of females in a clutch decreases at constant temperatures between , and of males between . Temperature in natural nests is not constant but varies between nights and days. Foremost females hatch in natural early nests when initial temperature inside nests ranges between . The percentage of male hatchlings increases in late nests located in sunny sites. Hatchlings are long and weigh on average when one month old. They grow about per month and reach a body length of when two years old. Sympatric predators The distribution of the mugger crocodile overlaps with that of the saltwater crocodile in a few coastal areas, but it barely enters brackish water and prefers shallow waterways. It is an apex predator in freshwater ecosystems. It is sympatric with the gharial (Gavialis gangeticus) in the Rapti and Narayani Rivers, in the eastern Mahanadi, and in tributaries of the Ganges and Yamuna rivers. The Bengal tiger (Panthera tigris tigris) occasionally fights mugger crocodiles off prey and rarely preys on adult mugger crocodiles in Ranthambore National Park. The Asiatic lion (Panthera