Nero, the Circus Lion by Richard Barnum

Nero lived in the jungle with his family, his mom and dad, his brother and sister. He liked to play with his friend Switchie, who tends to get Nero into trouble. One day, Nero's dad took him hunting, but instead, Nero gets caught in a trap. He ends up in a circus, where he has more adventures. Richard Barnum is a pseudonym of the Stratemeyer Syndicate, which mass-produced children's books.