Tropical rainforests are incredibly diverse ecosystems that are home to a wide range of plants and animals. Among the many fascinating creatures that inhabit these rainforests, one notable example is the toucan.

The correct answer is option 'D', the toucan, as they are indeed found in tropical rainforests. Let's explore why this is the case in more detail.

Toucans are a group of birds belonging to the family Ramphastidae. They are known for their large and colorful bills, which can be as long as their bodies and are used for a variety of purposes, including feeding, attracting mates, and establishing territory.

Toucans are primarily found in the tropical rainforests of Central and South America. These rainforests provide the perfect habitat for toucans due to their high levels of biodiversity and abundance of fruit-bearing trees. Toucans have a diet that primarily consists of fruits, but they also eat insects, eggs, and small vertebrates. The wide variety of fruits found in tropical rainforests ensures that toucans have a constant food source throughout the year.

Tropical rainforests also provide toucans with suitable nesting sites. Toucans nest in tree cavities, which are abundant in the dense vegetation of rainforests. The tall trees and thick foliage of the rainforest canopy provide protection and shelter for toucans and their nests.

Moreover, the warm and humid climate of tropical rainforests is well-suited for toucans. These birds have adapted to this environment and can withstand high temperatures and high levels of humidity. The rainforest canopy provides shade and protection from direct sunlight, allowing toucans to regulate their body temperature.

In conclusion, toucans are indeed found in tropical rainforests due to the abundance of food, suitable nesting sites, and the favorable climate that these ecosystems offer. Their vibrant appearance and unique bill make them a fascinating and iconic species within these diverse and vital habitats.