Which of the following represents a means of manipulating wildlife habitats?

The correct answer is putting up fences, as this represents a direct means of manipulating wildlife habitats. Fences can control and manage animal movement, protect certain areas from browsing pressure, and limit access to sensitive habitats. This allows for improved management of wildlife populations, as it can reduce human-wildlife conflicts and aid in the conservation of specific species by preventing overgrazing or trampling in vulnerable areas.

In contrast, while building homes, planting trees, and creating walking trails may have some influence on wildlife habitats, they do not serve as direct manipulations aimed specifically at altering habitat conditions for wildlife. Building homes typically disrupts natural habitats rather than manipulating them for conservation purposes. Planting trees can enhance habitat in certain contexts but is less direct than the specific control provided by fencing. Creating walking trails, while facilitating human access and potentially benefiting certain outdoor activities, can also fragment habitats and lead to disturbances, thus not serving as an effective habitat manipulation for wildlife management.