Canal de Castilla Rey (Palencia), considered the beginning of the Northern Branch, Valladolid and Medina de Rioseco, lying at the end of the Southern Branch and Campos Branch respectively. The countryside crossed by the canal is of interest for its birdlife. In the Tierra de Campos there are two large Special Protection Areas ("La Nava-Campos Norte" and "La Nava-Campos Sur") which are notable for the birds such as great bustards ("Otis tarda") which live in the dryland farming areas (sometimes described as "steppes") which are typical of the region. The canal, on the other hand, provides habitats for wetland birds such as the
Edwardsiella tarda Edwardsiella tarda Edwardsiella tarda is a member of the family "Enterobacteriaceae". The bacterium is a facultatively anaerobic, small, motile, gram negative, straight rod with flagella. Infection causes Edwardsiella septicemia (also known as ES, edwardsiellosis, emphysematous putrefactive disease of catfish, fish gangrene, and red disease) in channel fish, eels, and flounder. "Edwardsiella tarda" is also found in largemouth bass and freshwater species such as rainbow trout. It is a zoonosis and can infect a variety of animals including fish, amphibians, reptiles and mammals. "Edwardsiella tarda" has also been the cause of periodic infections for various animals within zoos. "E. tarda" has