More a style of representation than a period the realism tries to reproduce reality true to life. There are many different forms of realism such like socialist realism, social realism, and magic realism.
Animal representations are among the oldest motifs of human painting (as we find them in prehistoric cave painting) as well as of fine art.They inform us about the relation between man and animal in their time. However, pure animal images, where animals are not only symbolical attributes of the persons depicted, are a rather young development. In ancient times and in the Middle ages animals referred mostly to certain qualities of the depicted persons or they symbolized gods. In the Renaissance perception and representation of animals changed. A first high point of the representation of animals was the Dutch animal genre painting of the 17th century. In modern times it was the expressionist Franz Marc who created a great number of animal pictures.