Consider the following scenario:

A significant decline in fish populations occurs in the habitat of a semi-aquatic bird population. There are two groups of birds in the population that differ in leg length and diet. Long-legged birds eat fish, while short-legged birds eat insects. The insect population remains stable.

What is the main selective pressure in this scenario?

(1 point)
Responses

bird population
bird population

fish population
fish population

insect population
insect population

leg length
leg length

1 answer

The main selective pressure in this scenario is the fish population. This is because the long-legged birds, which rely on fish as their primary food source, are directly affected by the significant decline in fish populations. Since the short-legged birds eat insects and the insect population remains stable, their food source is not affected. Therefore, the decline in fish populations creates a selective pressure on the long-legged birds.