Family
Prior to being placed in Hec and Bella's care, Ricky is an orphan. None of his foster parents wanted to adopt him, and he could never truly make any friends. He was essentially alone. As a result, he is antisocial and out-of-touch, considered a delinquent by the authorities. When he first gets paired with Hec and Bella, he is unable to really integrate himself in their family, and tries to run away a few times. However, Bella shows Ricky some understanding and kindness, and he acclimates to family life.
When Bella dies and it looks like Ricky will have to go back to Child Services, he attempts to run away, but Hec follows him. In the bush, Hec and Ricky form an unlikely friendship, and the disgruntled Hec comes to feel fondly towards the feckless orphan. Their relationship is companionable and familial, and we see the ways that Ricky's attitude is improved by his sense that he belongs in a family. Thus, the theme of family, no matter how nontraditional or dysfunctional, is central to the film.
Survival and Self-Reliance
Another important theme in the film is survival. After Hec and Ricky enter the forest, they have no one else to rely on to survive but themselves, and Hec teaches the young boy a lot about survivalism. They must find shelter, food, entertainment, and just about everything else by themselves. A recurring joke throughout the film is the fact that Ricky is an overweight and exceedingly clumsy young man, who often gets himself into a lot of trouble.
Throughout the film, Hec and Ricky must not only survive in the bush itself, but also survive in their fight against the authorities. They seek not only to make a sustainable home in the forest, but also to evade the people who are looking for them. In the process of trying to avoid getting taken in by the authorities, Ricky and Hec learn that they quite like relying on themselves and their wits to get by.
Loss
A powerful theme in the film is dealing with loss. In the film, Hec and Ricky deal with the very unexpected loss of the lovable matriarch Bella. Both Ricky and Hec are heartbroken, and even though the funeral is presented in a humorous fashion, we understand that they feel completely lost and aggrieved because of her absence. In many ways, the film is about how the two of them pick themselves up and carry on in the wake of such a devastating loss. The two companions work through their grief by bonding with each other in the bush, a place that Bella held very dear.
Toughness
One of the more humorous elements of Ricky's personality is the fact that he thinks of himself as quite tough, even though he is a pudgy and uncoordinated boy who is basically completely harmless and non-intimidating. The people he looks up to are people like Tupac and other "gangsters," as he calls them. Thus, a humorous motif becomes the discrepancy between Ricky's self-image and his actual personality. By contrast, his foster father, Hec, is genuinely very tough and able to survive by his wits in the wilderness. The two make an unlikely pair, but eventually they become an unstoppable unit. The final sequence of the film is particularly funny—while simultaneously being incredibly suspenseful—because it is the fulfillment of Ricky's fantasies of "gangster" glory, complete with guns and a car chase. Ricky gets to feel like a character in The Fast and the Furious, which seems to be his greatest desire.
Growing Up
More than anything, the film is a coming-of-age story for Ricky. It tells the story of a young boy, neglected by the system, who learns to grow up and feel more responsible for his own destiny. In the beginning, he is completely powerless and ineffectual, but by the end, he has matured a bit and found a sense of place and belonging in the world. With the help of Bella and then Hec, he develops confidence and maturity.
Nature
The title itself alludes to this important theme in the film. Nature plays a huge role in the narrative. When Ricky arrives at Bella and Hec's, he sees how connected they both are to the land on which they live, and admires their ingenuity in the natural world. Bella teaches him to hunt and tells him that she wants to be buried in the bush. Hec is a survivalist who knows exactly what to do to stay alive for long periods in the bush. Through them, Ricky learns the ways of nature and begins to consider himself a "wilderperson," or someone who belongs in the wilderness. By the end of the film, even after all they have been through, Ricky and Hec find great fulfillment going into the bush and connecting with nature, particularly when they discover the huia, a bird that was previously thought to be extinct.
Rumors
A darkly humorous narrative thread in the film is the fact that everyone in the town believes that Ricky has been kidnapped by Hec, and that Hec is a child molester. The rumor gets started when Ricky misguidedly tells some hunters about his and Hec's relationship but explains it so vaguely that it sounds like sexual abuse. Soon enough, everyone believes that Hec is a predator, even though the viewer knows this is not the case. This serves to show that rumors spread quickly and are difficult to dispel.
