New Koalas Boost Breeding Program at Saitama Children’s Zoo

In July, two koalas – Arnold, a 2-year-old male, and Bubbles, a 3-year-old female – were transferred from Queensland, Australia, to Saitama Children’s Zoo in Higashimatsuyama, Saitama Prefecture. The animals were placed on public display in late August. The zoo reports that Arnold settled quickly and began eating soon after arrival, while Bubbles appeared nervous and required a longer adjustment period. With their addition, the facility now houses nine koalas.

Japan Times

Importing koalas from overseas is deemed essential for preserving genetic diversity among Japan’s captive population. The Japanese Association of Zoos and Aquariums notes that the national koala count peaked at 96 in 1997, fell to 35 in 2013, and recovered to 61 individuals across seven facilities by the end of 2025. The new pair introduces fresh bloodlines, enabling the zoo to pair males and females from different lineages and strengthen future breeding prospects.

Japan Times

The zoo sources eucalyptus – the koalas’ primary food – from roughly seven suppliers to ensure a steady supply. It also acknowledges that koala-specific infectious diseases contribute to high juvenile mortality, with many individuals dying before reaching one year of age, though some causes remain unidentified. Cooperation among Japanese zoos is highlighted as a key strategy for sharing animals and coordinating breeding programs.

Japan Times

Zoo director Sachiko Noguchi emphasized the strategic importance of the newcomers, stating that their arrival supports the zoo’s long-term goal of safeguarding the species within Japan. The Japanese Association of Zoos and Aquariums reiterated that maintaining a genetically diverse captive population is critical for the species’ overall conservation.

Japan Times

“We want to take good care of these two newcomers because they bring new bloodlines and will play an important role in the future of koalas in Japan,” — Sachiko Noguchi, the zoo’s director

Japan Times