Jaguars don’t just live in the rainforest. The jaguar used to live in California until the last one in the state was shot in 1860. Jaguars continued to survive in Arizona, Texas and New Mexico until the 20th century. These American states do not have rainforests!
The jaguar is normally thought of as living in dense tropical forest but it also inhabits a wide range of other habitats. These include arid scrub and swampy grasslands. They also live in lowland and dry deciduous forest. And can be seen in mangrove swamps.
The jaguar does like water. It is an excellent swimmer and likes to hunt near streams and watercourses. They’ll attack and kill caiman by crushing their skulls in their jaws. They like turtles too.
Jaguars often follow large rivers. An elderly male jaguar was shot in Baja California in 1955. It was surmised that this cat had crossed the Sonoran Desert and Colorado River.
So, the question: ‘why do jaguars live in the rainforest?’ is incorrectly formulated. Sorry about that. That said, jaguars are often found in a range of tropical and subtropical habitats at sea level to around 1,200 meters. Although this versatile cat has been recorded as living at 2,700 meters above sea level in Bolivia.
If jaguars typically live in tropical habitats it is because that is the place where jaguar prey is most abundant. It is all about survival ultimately. This cat’s distribution has shrunk markedly over the past 100 years to a fraction of its former size due to increased human population size and ensuing activity.
Source: Wild Cats of the World page 307.