What are two possible reasons a frog population can change

I don't know for sure because my answer is simple but, A frogs population could change because they could get hunted and they could reproduce

Step-by-step explanation:

A frogs predator could kill and eat the frogs which would make the population decrease. A frogs predator could get hunted and killed off and the frogs could live and reproduce

These causes include habitat modification and fragmentation, introduced predators or competitors, introduced species, pollution, pesticide use, or over-harvesting. However, many amphibian declines or extinctions have occurred in pristine habitats where the above effects are not likely to occur.