Isolation
Isolation is a major theme in The One and Only Ivan. Throughout the novel, Ivan reflects on his isolated and solitary existence as the only gorilla in the mall circus, where he has lived for 27 years. Although Ivan has made friends with Bob, Stella, and Julia, he often yearns to be with the other gorillas he sees on the TV. However, even when he has the opportunity to integrate into a gorilla troop, Ivan finds that his life of isolation has lead him to lose touch with his natural instincts; it takes him time to relearn the traits of a silverback and live peacefully among other gorillas.
Artistic Expression
Throughout The One and Only Ivan, artistic expression is a dominant theme. From his infancy in the wild, Ivan gained the name Mud because of how he would paint on his mother's back using mud. While being raised in Mack and Helen's house, Ivan used cake frosting to paint on the refrigerator door. Later Julia slipped Ivan paper and crayons so that Ivan could draw while in his cage. When asked by Ruby, Ivan is forced to confront the question of why he makes art; he realizes that he makes art because it makes him feel quiet inside. What he doesn't understand is that he gravitates to art because it acts as a form of expression and freedom in a life that is otherwise severely limited. Ultimately, it is artistic expression that enables Ivan to communicate his desire to see Ruby taken to live a better life in a zoo.
Absent Matriarchs
There are several examples of absent matriarchs in The One and Only Ivan. Ivan's mother, whose back he once painted on, was killed and dismembered when Ivan was poached as an infant. Julia comes to the mall with her father because her mother is sick at home and unable to care for her. While being raised by Mack and his wife Helen, Helen leaves Mack, and soon Ivan is moved to the mall. Stella, after briefly living as a maternal figure to the orphaned Ruby, dies from her infected foot, leaving Ruby without parents again. The absence of matriarchs in the narrative leaves many of the main characters isolated and lonely; they must console each other in the absence of the warm and safe presence of their mothers.
Storytelling
Storytelling is a major theme in The One and Only Ivan. While the book itself is a form of storytelling, characters within the book tell stories to each other in moments of stress and discomfort. When Ivan can't sleep, he goes to Stella to hear stories of her past. Later, when Ruby can't sleep, Ivan tells her stories to help her drift off. Storytelling helps Ivan to access his repressed memories and get in touch with his submerged identity as a mighty silverback. Ultimately, the story the media tells of Ivan and Ruby's mistreatment leads to the animals being moved to more humane living conditions at the zoo.
Animal Confinement
Early in The One and Only Ivan, Ivan considers his glass-enclosed territory at the mall to be his "domain." As the novel progresses, Ivan comes to terms with the fact of his confinement, and he begins to call his domain a cage. Ivan also builds a growing understanding of how his confinement has impacted his psychology: even when he has a chance to roam free with other gorillas, he retreats to his cage, to which he has become accustomed. Once he has integrated into the gorilla pasture, Ivan understands that he is still confined by walls, though he recognizes that he is living in preferable, if somewhat compromised, circumstances.
Animal Mistreatment and Trauma
Animal mistreatment and its subsequent trauma is a major theme in The One and Only Ivan. Early in the book, Ivan comments on the scars visible on Stella's body, which come from the chains used to confine her in the circus. Stella, who is demoralized after a life of mistreatment, tells Ivan that he is repressing his memories. After Stella's death from neglect, Ivan does access his memories, confronting the gruesome killing and dismembering of his parents and the death of his sister. By the end of the book, the mall circus closes after enough people witness the evidence of animal mistreatment that has gone on there.
Human Greed
Early in the novel, Ivan comments on how he understands human speech but doesn't understand human behavior. From his domain he watches humans buying bags of things from the mall while never satisfying their need for more. Greed also leads Mack to cut costs and neglect his animals. Ultimately, it is Mack's greed that precipitates the closure of the mall: desiring media attention because he thinks it will bring customers, the public grows outraged at the conditions in which he keeps his animals.
