effect of habitat modification on

Explores some of the ways in which humans have affected bird populations across the nation and the steps that have been taken to protect them.

Introduces young readers to the importance of wetland areas to the Earth's ecosystem, and discusses threats against areas such as the Everglades and the Arcata Marsh and Wildlife Sanctuary, along with the efforts to restore and protect wetland areas.

Explores how a succession of historical experiences repeat a cycle in which overfishing and sweeping changes to rivers and seas render the world inhospitable to salmon.