The document discusses the niche and habitat of mallard ducks. It describes how mallards live near bodies of water and eat a variety of plants, insects, fish, and worms. It also outlines the mallards' reproduction cycle and predators. Food chains and webs involving mallards and other local organisms are depicted. The document examines different population sampling techniques used by ecologists to study animals. It analyzes data on stream quality, water testing, and soil testing in relation to how they could impact mallard duck habitats and survival.