How could the use of pesticides to kill ticks contribute to a decline in the oxpecker population?

The correct interpretation revolves around the relationship between the oxpecker population and their primary food source, which is ticks. Many species of oxpeckers, known for feeding on ticks found on large mammals, rely heavily on these parasites as a significant component of their diet.

If pesticides are used to kill ticks, the direct consequence is a substantial decrease in the availability of this food source for oxpeckers. With diminishing food resources, the oxpecker population may struggle to find enough nourishment to thrive. This decline in food availability can lead to reduced breeding success and overall population decrease for the oxpeckers, showcasing how interconnected these species are within their ecosystem.

The other options either misrepresent the relationship or imply actions that do not directly link to the decline of the oxpeckers due to tick extermination.