The rotating images under "What's New" and their respective links are defined in an XML file.
Under the "Zoo Explorer" the text and links in the drop down (or up) are defined in another XML file. As the file is parsed, the menu is built dynamically to the correct size.
Also under the "Zoo Explorer," the animal scroll bar is built dynamically, with paths to each animal's SWF file, its name, and its link defined in the XML. As each animal loads, the slider is dynamically resized, and animation variables adjusted.
Fuse Kit is used throughout for roll overs, image fades, movement, etc. The animal slider though, was more complicated to achieve the right feel (including the nice elastic bounce when the last animals are reached), so a combination of onEnterFrame / setInterval / Fuse was used.
A finely tuned sequence was used to load in the separate SWFs/JPGs (What's New images, Zoo Explorer image, animal slider SWF, drop up SWF, individual animal SWFs) in the necessary order.