Making Panda Cakes

Su Lin admires her cake.

This week we’re celebrating three panda birthdays at the San Diego Zoo! Are you curious to learn who makes those delightful ice cakes that the pandas find so entertaining? It’s the Forage Warehouse staff of the Zoo’s Nutritional Services Department! Here’s how they do it:

Animal enrichment has become an essential part of caring for animals in a zoological setting. There are various types of enrichment, which include social groupings, exhibit design, sensory stimulation, and different feeding strategies. One of the most common types of enrichment involves feeding strategies. Ice blocks filled with various vegetables and fruits can be used to keep an animal engaged and curious.

First, containers are filled with a bit of water and allowed to freeze.

Ice blocks are a very good source of enrichment because they are low in calories, they keep animals preoccupied for a long time, and the animals can easily manipulate the ice blocks. The ice blocks can be used for many different species of animals such as elephants, rhinos, monkeys and other primates. But the pandas are probably our most famous “customers.”

Decorative items, such as bamboo leaves, are added, along with more water to freeze in place.

Many different materials can be used to create ice blocks and ice cakes, such as trash cans, buckets, flowers, fruits and veggies, food coloring, various browse (leafy material harvested from the Zoo’s trees and bushes), different types of molds, ice cube trays, and spray bottles. Which materials we use are dependent upon the animal. We use items that are in their daily diet or have been approved by the nutritionist for enrichment. For the pandas, we can use yams, carrots, apples, bamboo, and honey.

A drill makes holes for bamboo poles or honey.

First, we place items such as browse or just water into the container. We add small amounts of water to the container and place it in the freezer. Various items such as bamboo, flowers, fruits, vegetables, and browse can be placed along the edges of the container to create a colorful border. We keep adding water to finish the ice block. To create a tier for our panda birthday cakes, we remove an ice block from a smaller container, flip it over, and place it on top of an ice block in a larger container. We add water to the larger container to freeze the top tier in place. For a third tier, we drill holes in the second tier and then place the third tier in the holes and add water to freeze it in place. A drill can also be used to make holes for different decorations such as carrots, honey, browse, and ice numbers. A number can be created in a shallow tub and cut out on a band saw; a small hole is drilled into the top of the cake and the number then placed in that hole and frozen in place.

Zhen Zhen's cake slowly takes shape.

Cake molds, ice cube trays in various shapes, and even cookie molds can be used to create fun shapes for the cake decorations. Food coloring is used to make the cake decorations more colorful and stand out. We brainstorm to try to come up with different looks every year. Often, when we are making cakes we get ideas for what to do next year, so it’s always on our minds. We start on each cake two to three weeks ahead of the big day, depending on how elaborate the cake is. Even though we may spend quite a bit of time making these panda cakes, we would never neglect our responsibilities with the rest of our Zoo collection. We put a lot of love in our creations and truly enjoy this aspect of our jobs!

Do you think Zhen Zhen enjoyed her 3rd Birthday cake?

On the day of the big event, the cake is delivered to the birthday panda. Cakes vary in size and weigh 50 to 150 pounds; they are transported by cart (for a smaller cake) or truck to the exhibit, where we help the keepers place our gift in an appropriate spot for viewing and photos.

Ice cakes are a great source of enrichment not only for the animals but for Zoo guests, too. It’s fun for us to watch the pandas enjoying their cakes, but it’s even more satisfying to see the guests’ reactions and to hear their comments!

Debbie Lowe, Kelly Lee, and Debbie Tanciatco are members of the San Diego Zoo’s Nutritional Services Department and ice-cake makers extraordinaire!

Here’s video of Su Lin’s birthday morning…

Here’s video of Zhen Zhen enjoying her third birthday…