Use the passage to answer the question.

A wolf pack may have as many as twenty wolves. By three weeks of age, wolf pups are able to play. Most packs are led by an adult male and adult female. The average size of a wolf litter is around four pups.

Which type of evidence does the author use to develop an argument?

The passage does not mention any argument being developed by the author. It is a descriptive passage providing information about wolf packs and their characteristics. Therefore, the type of evidence used in this passage would be observational or factual evidence. The author presents facts about the size of wolf packs, the age at which pups are able to play, the typical leadership structure within packs, and the average litter size of wolves.