Semi-aquatic and Terrestrial Wildlife
In addition to aquatic organisms, riparian wildlife uses rivers and streams as travel corridors. These include semi-aquatic species such as muskrat, mink, otter, frogs, stream salamanders, turtles, and snakes. Within the larger landscape, rivers and streams provide vital links connecting wetland, aquatic, and terrestrial ecosystems. In developed areas, rivers and streams often represent the only available travel corridors for many wildlife species. In arid environments, stream channels and riparian corridors offer wet and humid conditions during extended dry periods and serve as movement corridors for terrestrial and semi-aquatic amphibians.
Where rivers and streams provide vital movement corridors for semi-aquatic and terrestrial wildlife, oversized culverts and expanded bridges can be used to facilitate movement essential for maintaining viable wildlife populations. In designing structures to accommodate wildlife it is important to consider structure height and openness (cross-sectional area relative to length), and to provide dry passage (banks or dry streambed) during significant portions of the year.