Imagine a white-footed mouse population living in a grassy meadow. The meadow is an optimal habitat for this population because of the grasses that grow there. The mice are seed-eaters and they eat grass seeds all summer and fall. Scattered honeysuckle shrubs provide cover from the few wild predators that live in the woods. In addition, a farmhouse at the edge of the meadow provides nesting habitat, which is necessary for reproduction. There is also a vole population (Microtus pennsylvanicus) occupying the same meadow that competes with the mice for food. How do the following changes impact the carrying capacity (K) of the mouse population in the meadow?
Increases K
Decreases K
Has no impact on K
i. The voles contract a vole plague and are wiped out in one generation.
ii. Nearby wetlands are drained, decreasing the amount of water available.
iii. The human family abandons the house, providing more nest sites.
iv. A new family moves into the house and they have a cat.
v. A parking lot is built, shrinking the habitat area.
vi. An invasive grass establishes in the meadow, providing a new seed source.