Question

which factor would most likely cause a population decrease? high birth rate ability to avoid predators specialized niche stable chemical conditions

Explanation:

A high birth rate would increase population. Ability to avoid predators would help population survive (not decrease). Stable chemical conditions are positive for population. A specialized niche means the population is adapted to a very specific environment. If that environment changes (e.g., due to natural disaster, human interference), the population, being specialized (not adaptable to new conditions), is more likely to decline.

Answer:

specialized niche