Owls and mice have a predator/prey relationship. owls are the predators, and mice are the prey

what happens to the mouse population when there is a decrease in the owl population

When there is a decrease in the owl population, the mouse population is likely to increase. With fewer predators, the mice have a higher chance of survival and reproducing, leading to a larger population size. This increase in the mouse population could have various ecological impacts, such as competition for resources, potential habitat destruction, or an increase in the spread of diseases associated with mice.