What is a common effect of pesticides on animal populations?

The effect of decreased reproduction is a well-documented consequence of pesticide exposure in animal populations. Many pesticides disrupt hormonal systems, impair reproductive functions, and cause developmental issues in offspring. This leads to a decline in population numbers over time as fewer young are born or survive to maturity.

In contrast, options such as growth enhancement, higher tolerance to pollutants, and increased biodiversity are generally not outcomes associated with pesticide use. Pesticides typically do not promote growth; rather, they can have toxic effects on organisms, inhibiting their growth or causing lethality. Tolerance to pollutants is not a direct effect of pesticide exposure but may pertain to specific adaptations seen in some species, which is not a general or commonly observed outcome. Finally, pesticides often have detrimental effects on biodiversity, leading to declines in various species rather than an increase. Thus, decreased reproduction stands out as a significant and common effect of pesticide exposure on animal populations, aligning with the observed trends in ecological studies.