Question

The sword-billed hummingbird has the longest bill of all birds compared to its body size. Its beak is perfect for drinking nectar from the very deep Passiflora mixta flower.
This is an example of what type of relationship?
A. Co-evolution
B. Commensalism
C. Parasitism
D. Predator-prey

Answer 1

This is an example of co-evolution.  

Explanation:

In co-evolution one species or a number of species evolve according to the changes in another species. Here the evolution of the beak of humming bird according to the shape of Ossifloramixta flower is an example of co-evolution. Co-evolution is common in the nature.  

Bees, insects and butterflies commonly co evolve with the flower plants and  vice versa. Co-evolution is of two types. The first type is specific co – evolution where only two parties are involved in co-evolution. In the second type of co-evolution namely diffused co-evolution many species evolve in response to specific traits in a species.