Chapter 7 Summary and Analysis

Darwin heads toward St. Fe, about 300 miles north of Buenos Aries along the Parana River. Recent rains make the road very difficult, especially for the many carts with huge wheels. He passes by vast expanses of thistles where robbers hide and cattle can be lost in the labyrinth. Few wild animals inhabit the thistle fields except a rabbit-like creature called a bizcacha and a small owl. The gauchos tell Darwin the bizcacha feeds off the roots of the thistles and has a curious habit of collecting hard objects in a pile near the entry to its burrow. If a person loses something like a watch, it may be found by searching through bizcacha piles. Darwin has no idea why the animals do this.

The small owls feed on mice and snakes, which Darwin verifies by inspecting the contents of their stomachs...