Like most felines, the Sumatran tiger is a solitary animal that reigns over a territory whose size depends on the abundance of prey. A male's territory can cover that of two to four females. He marks his territory by scratching trees and spraying urine. Males and females only meet during mating season. The mother will raise her cubs alone for about a year and a half.

It hunts from ambush, its stripes allowing it to camouflage itself in the vegetation. It is capable of swimming several kilometres.

The Sumatran tiger differs from other tiger subspecies in that it has a darker coat, more numerous and tighter stripes, and long white whiskers.

The Sumatran tiger is believed to have been isolated on the island when sea levels rose between 6,000 and 12,000 years ago. As a result, it has genetic differences from mainland tigers (Bengal tiger, Siberian tiger, etc.).

The global tiger population has declined by 95% over the last 100 years. Deforestation is drastically reducing their habitat. They also face poaching and illegal logging.

Its increasingly fragmented population fell to less than 4,000 individuals in 2020, with four of the nine tiger subspecies already extinct in the wild. The Sumatran tiger is currently the rarest subspecies, with fewer than 400 animals still living in the wild. Numerous international and regional programmes, both in situ and ex situ, are actively working to save the Sumatran tiger: breeding programmes, population monitoring and reinforcement, creation of reserves and rehabilitation centres, etc.

Kasih means "love" in Indonesian. The female at the Reserve was born on 2 June 2013 at Chester Zoo in the United Kingdom and arrived at the Haute Touche Zoological Reserve in June 2015. Kasih is very protective of her territory and expresses her displeasure by growling.

Toba is the name of a large lake on the island of Sumatra. The male at the Reserve was born on 10 August 2011 at the Wildlife Heritage Foundation in the United Kingdom. He joined the Haute-Touche Zoological Reserve in November 2013. He has a calm and gentle temperament.

The arrival of the female in 2015 was part of a European breeding programme. After initial visual contact and observing friendly behaviour between Kasih and Toba, the animal teams decided to introduce them into the same enclosure.