Rhythm & Hues created 300 pairs of animals for use on the ark and fifteen pairs with higher detail for closeup shots. R&H was also assisted by C.I.S. Hollywood, another visual effects company, who provided a large number of composites, involving hundreds of greenscreen animal elements. In scenes where there are multiple species of animals, crew members would film the animals on the greenscreen and R&H and C.I.S would digitally add the animals one at a time, sometimes taking several weeks to a couple of months. Andy Arnett, the animation supervisor, declared that "The research was extensive. It took six or seven months to perfect the look and feel of the animals before we had the first shot out the door."