Early removal of old tigers before they begin attacking humans, however, requires regular monitoring (camera trapping and tracking). Tracking tigers can also alert the local communities about the location of a dangerous tiger. If the tiger is young and wounded, it can be treated and relocated inside the core of the reserve if the space is unoccupied

In recent days, human casualties due to tiger attacks are increasing in the surroundings of two key tiger reserves: Bardia and Chitwan National Parks. To understand why this is happening, let us first understand the behavioural and feeding ecology of tigers.

Tigers are solitary large predators; however, during the mating season, both the male and female can be seen together for about 5-6 days of the oestrus period.

Also, females are accompanied by their cubs, who become independent and disperse from their mother at the age of 18 to 24 months. Female siblings occasionally can be seen together.

Tigers are shy of humans, therefore, prefer an undisturbed habitat with plenty of prey, usually large wild ungulates. They generally avoid the fringe habitats where humans are present and select the core of the reserve. In Nepal, much of the tiger diet consists of chital and wild boar, but it also prefers large prey such as gaur, swamp deer, sambar and nilgai. Other prey species are the hog deer, barking deer and monkeys.

Occasionally, when opportunity arrives, domestic animals such as cows, buffaloes, goats and pigs are also preyed upon. Generally, a tiger kills equivalent to one medium sized prey (similar toa chital deer) in a week, thus about 50 deer are killed in a year. To sustain a tiger, it is estimated that about 500 wild animals are essential.

Humans are not the natural prey of tigers. Generally, if a tiger sees a human from a distance, it hides.

However, when humans suddenly appear in front of a tiger, it may feel threatened and attack in defence. A tigress with her cub is also aggressive and dangerous.

It is a natural law that every creature on this earth protects its offspring from danger. Also, when tigers are with their kill, they are dangerous. Very old and weak tigers are unable to chase and hunt, therefore, they look for easy prey such as humans or domestic stock. Such tigers are mainly displaced from the core of the tiger habitat and occupy the fringe of the reserve and stray into human settlement in search of easy prey.

If a reserve has reached its carrying capacity, dispersing sub-adults might be displaced to the fringe.

In the fringe, prey species are naturally less and sparse. So tigers may suffer from hunger for several days, compelling them to attack humans or livestock when the opportunity arises.

They may also intrude into human settlement are as for food.

Scientists argue that some tigers may habituate themselves to become a man-eater (unusual behaviour).

Once a tiger tastes human blood, it wants to taste again. However, man-eaters make up only a small fraction of the tiger population. This unusual behavior has been observed in several tigers of Sunderban of Bangladesh and India but is very rare in other tiger landscapes.

The Nepali government is committed to doubling the tiger numbers by 2022.

A summit held in 2010 in St Petersburg, Russia of all tiger range countries made a declaration to double their tiger population. Due to intensive conservation efforts, Nepal has almost achieved this target.

Along with tiger population increase, incidents of human casualties are also increasing.

The National Parks and Wildlife Conservation Act, 1973 provides provision for killing of problem animals.

Section 10 (a) of this act allows for the killing of protected species by prescribed officers. This act allows for the destruction of rogue wild elephants, man-eater tigers and wildlife that suffer from disease or have become disabled and may not survive. Section 10 (b) of the same act allows for the killing of wildlife which come out of the forested area and cause considerable loss to human beings or to domestic birds and animals.

They may be killed, captured or chased by order of the prescribed officer.

What can be done to reduce the frequency of human casualties? Management of problem tigers is the key. It is wise to assess where the casualties occurred — inside the forest reserve or in a human settlement.

If the tiger came to a human settlement and attacked the people, then assess whether the tiger was very old or impaired (wounded or had dental issue).

If this is the case, killing of such a tiger, which is permitted by law, can minimise further damage, since an old and unhealthy tiger will not contribute in reproduction.

Early removal of old tigers before they begin attacking humans, however, requires regular monitoring (camera trapping and tracking).Tracking tigers can also alert the local communities about the location of a dangerous tiger.

If the tiger is young and wounded, it can be treated and relocated inside the core of the reserve if the space is unoccupied.

It is to be noted that if there is another resident tiger, then conspecific competition may displace one of the tigers, and the displaced tiger may come to the fringe of the reserve.

The relocated tiger needs to be monitored to see if it again comes near the reserve border and intrudes into settlements. If the casualties occur inside the reserve core, it is likely that the tiger and human came face to face, and the former may have attacked the latter accidentally due to fear of threat. No management action is required in such a situation.

So avoiding an encounter with a tiger is the best option to stay safe, which means not venturing into the core of a tiger reserve.

While going to a buffer zone forest to gather forest products, avoid the dawn or dusk period when tigers are active. Also look for fresh signs and tracks of tigers, such as pugmarks and scat. Always go in a group and carry a sturdy stick. Do not disturb the animals by making noise in the forests.

Bhattarai is a researcher of human wildlife conflict and has worked for several years in protected areas of Nepal