Final answer:
Field mice and rabbits cannot make up the same population in an ecosystem as they are different species. They form separate populations but coexist within the same community, contributing to the ecosystem's species diversity. Population size and density are key factors in understanding their existence in the habitat.
Step-by-step explanation:
The concept of populations in an ecosystem notes that a population must be comprised of the same species. Therefore, field mice and rabbits cannot make up the same population because they are distinct species with different characteristics and reproductive strategies. These species do interact within a shared ecosystem, but they form different populations within a larger community. This community perspective allows us to understand how these populations coexist, interact, and compete for resources in their habitat.
Each population is defined by its population size and population density, which relate to the number of individuals and the number per area, respectively. For instance, we could express this as mice per acre or rabbits per square mile. Populations can have similar densities and yet move differently within their range; one may move in a herd while the other disperses randomly.
It is also important to consider that while these two species live in the same habitat, they do not necessarily access food from the same places within that habitat, which aids in their coexistence. Field mice and rabbits contribute to the species diversity of the ecosystem, an important factor in ecological studies. Their interactions within the community are crucial in understanding the dynamics of ecological processes.