a Drought hits the habitat of a semi-aquatic bird population. All ponds dry up, and fish populations decline. There are two groups of birds in the population that differ in leg length and diet. Long-legged birds eat fish, white short-legged birds eat insects. The drought has little effect on insect populations.

Question

What is the main selective pressure in this scenario?
**leg length
**insect population
**fish population
**drought