Biology of Puget Sound

This chapter describes the contemporary inhabitants of the Puget Sound region, in particular the trees, vegetation, marine and estuarine plants and algae, as well as the major groups of animals, such as the keystone predators and their prey. Puget Sound is also a major region for overwintering and migrating birds and butterflies and the main inflows of the Snohomish, Skagit, and Puyallup Rivers serve as sources of fresh water for the region's biota. The chapter includes descriptions of all the extant animals that are classified as chordates, implying they have had at least a dorsal notochord and/or a nerve cord during ontogeny. It deals with some of the snakes that inhabit the Puget Sound region. The relatively warm and dry climate, offered a multiplicity of habitats for small birds, mammals, reptiles, and invertebrates, the common prey for most snakes. Mid-sized and small prey mammals, usually rodents, are commonly seen in all parts of the Puget Sound region.