Family
Family is perhaps the most important theme in "At Hiruharama." In the short story, Mr. Tanner's grandfather and Kitty start a family together against all odds. The two were immigrants to New Zealand from Great Britain, where they both were cast away for being orphans. And it is in New Zealand where the two create something few would have thought possible: a family. After being together for many years, Kitty one day unexpectedly gives birth to twins. One of those twins, in fact, turned out to be Mr. Tanner's father. And Mr. Tanner's father, in turn, gave birth to Mr. Tanner.
Community
Community is another important theme in "At Hiruharama." Despite living in remote farmland far from other people and civilizations (their nearest neighbor is nine miles away), the Tanners have a deep sense of belonging in their community. Their neighbor, Parrish, lends Mr. Tanner's grandfather pigeons so that he could alert the doctor of Kitty going into labor. Brinkman, the couple's closest neighbor, also plays an important role in their life. Though he is a cantankerous person, his presence is often welcomed in Tanner's home. In fact, Kitty offers to cook a meal for Brinkman. Ironically, despite their relative physical distance from their neighbors, Tanner's lives are held together by their community, which they adore.
Upward mobility
The theme of upward mobility plays a vital role in "At Hiruharama." Although both Kitty and Mr. Tanner's grandfather move to New Zealand unwillingly, immigrants typically move to another country in search of new and better opportunities. In future generations, however, Tanner's decision to move to New Zealand paid dividends for them. One of their family members became a lawyer, a profession that was held in high regard in New Zealand (and across the world) during their lives. Besides that, Mr. Tanner, the narrator of the story, decides to leave New Zealand so that his family could be more upwardly mobile in a more populated place with better opportunities. Ultimately, people act in a way that preserves their self-interest. They do what is best for themselves and for their family. And frequently, those decisions come when they search for ways to materially improve their lives.