Final answer:
The mouse population may have experienced zero population growth due to high predation levels, but other factors like food availability, disease, and environmental conditions also shape population dynamics. A high predation rate can contribute to keeping prey population sizes in check.
Step-by-step explanation:
It is possible that the mouse population did experience zero population growth between 1985 and 1990 due to a high number of predators. This inference can be made based on an understanding of population dynamics where predation is one factor that regulates population size. According to the logistic model, populations might fluctuate based on various factors like food availability, predation, and disease. However, if a population does not grow over a certain period, it could be due to an increase in these regulating factors.
The provided study suggests that the predation by big predators can have significant effects on the population size of prey species. In the case of mice, if they were heavily predated upon, this could have kept their numbers in check, despite other conditions being favorable for growth. Conversely, in a population of voles studied for 20 years, a singular generation showed an 80% survival rate to reproduction age, leading to a population increase. This was inferred to be due to either more food availability or decreased predation.