Smithsonian National Zoological Park l Friends of the National Zoo



Enriching Our Exhibits

Animal enclosures that mimic the wild just don’t look pretty. They help keep animals healthier and happier.

By Allie Killam and Mark Tuai

Patiently waiting, a fishing cat perches at the water’s edge. He uses his webbed paws to tap the surface of the pond, imitating the motions of an insect. A hungry fish rises to the top of the pond, looking for dinner. Bad move. In a flash, the cat lunges beneath the surface and devours the fish.

The Smithsonian’s National Zoo goes to great lengths to create moments like that. This scene took place not in the wild, but within the fishing cat exhibit on Asia Trail. Part of the Zoo’s mission is to provide its animals with the highest quality care, which begins with creating an enriched environment for every animal in residence.

“All enrichment begins with looking at an animal’s natural environment,” explains Heidi Hellmuth, curator of enrichment and training. “Enrichment keeps animals psychologically and physically active. They all have to problem-solve and deal with challenges in their natural environment. We are allowing them to be what they were meant to be.”

Drawing on Nature

(Mehgan Murphy/NZP)

Making sure an animal’s exhibit closely resembles its habitat in the wild can often require a lot of brainstorming. The Zoo has had multiple opportunities to begin from scratch, creating state-of-the-art exhibits and amply preparing for future residents. On other occasions, current exhibits are altered to maintain or further enrichment.

One crucial factor in maintaining a wild-like exhibit is climate control. Environments vary greatly from species to species, and in the wild, animals must cope with changes in the weather. For most of our indoor residents, climate control can be as simple as turning on a heat lamp for an iguana. Sometimes, though, keepers have to get a little more creative when creating weather enrichment for indoor animals. Doing so can include tweaking the temperature of the sea anemone’s tank or altering the amount of water available to desert animals.

For our outdoor residents, such as the flamingo flock, which hails from a more tropical region, things are a bit more complicated. “We find ways to extend their seasons,” explains Brandie Smith, the Zoo’s senior curator for mammals. For the Asian small-clawed otters, this means a heated pool maintained at roughly 70° and hot rocks (with interior heat coils) scattered throughout the enclosure. Whenever the temperatures are unbearable, animals have the option of venturing indoors.

The shirt-drenching rainforest in Amazonia is a prime example of the Zoo’s dedication to animal comfort. Kept at roughly 75° year-round, Amazonia relies on the sun and white-washed windows to create a greenhouse effect that traps heat and allows its inhabitants to feel right at home.

Another key factor in creating an enriched exhibit is the layout of the space. “We design it with the knowledge of animal behavior in the wild,” explains Hellmuth. “How do they utilize their environment? It’s incumbent upon us to modify that based on individual animal response.”

For example, a beaver in residence has a naturalistic habitat that provides access to plenty of logs. He chews them, but he has also developed a habit of gnawing on a metal pole. While the gnawing isn’t hurting the beaver, the Zoo is currently working on furnishing a replaceable wooden pole cover so the beaver may continue chewing on his upright “tree trunk.” Enrichment is achieved by paying careful attention to the animals. Even though the beaver has access to all the wooden logs he could dream of, he still wanted to chop down a tree.

Home Improvements

Maintenance supervisor Stephen Micciche works one-on-one with keepers, scientists, and behaviorists at the Zoo. He steps in when the keepers voice a need. “We do a lot of problem-solving, building prototypes, and installing,” he explains.

His team’s creations vary from simple parrot toys to rock walls and caves. The sloth bears currently aren’t spending much time in their cave, so the Zoo’s mason shop is coming up with a design to extend the roofof the cave so a bear will still be on exhibit but will feel secure and private, as well as protected from the elements.

Creating a naturalistic exhibit that still provides public viewing is “not easy to balance,” says Hellmuth. Because the public must work harder to see the animals, the Zoo is concentrating on ways to educate the public and show them where to look. Zoo volunteers are always happy to point out where the animals are “hiding” to visitors.

Orangutan on the O-Line
(Jessie Cohen/NZP)

In certain cases, providing an enriched environment actually makes the inhabitants more visible. Visitors can witness animals foraging for food or marking territory. Perhaps most spectacularly, zoogoers can watch the orangutans traverse the O Line just as they would move among the trees in their wild arboreal habitats.

Both Amazonia and the Small Mammal House hold mixed-species exhibits. By having multiple residents in one location, the environments closely resemble the proximity of other animals in the wild. The National Zoo illustrates its commitment to animal caretaking not just by providing these complex habitats, but by constantly striving to provide animals with opportunities to use their natural abilities. Instead of feeding animals in the same place at the same time every day, for instance, keepers hide food in different locations to encourage foraging.

Acting Naturally

Mindy Babitz, a keeper on Asia Trail, focuses on activity patterns in the wild as a basis for providing enrichment. “Life in the wild is hard,” she explains. Animals have to find food, seek shelter, and worry about predators. The animals at the Zoo don’t have those worries, so the keepers must come up with ways to keep them exhibiting normal behaviors. “We try to make them work for their food!” she adds with a laugh.

Sloth bear eating.
(Mehgan Murphy/NZP)

For the sloth bears, food is wrapped up in paper bags, and then left buried in various digging pits in the yard. Because they are accustomed to foraging, the bears receive numerous feedings in various locations to keep them moving throughout the day.

Wild cats tend to conserve their energy until feeding. Since most Zoo cats are unable to hunt within their exhibits, the staff find other ways for them to exhibit natural behaviors, such as tearing through a cardboard exterior to get to the meat inside. Luke, our adult male lion, once attacked a cardboard pig and repeated all the motions a wild lion would when attacking prey, including a neck swipe.

At times, keepers and volunteers move rocks, trees, and other structures around in the exhibit as if an intruder came through their territory. They then observe how the animal reacts to its changed enclosure, perhaps by marking its territory.

Other times, animals do the rearranging themselves. Francois, a male sloth bear, spends hours moving objects from his outdoor exhibit to his indoor enclosure. On one occasion, he ripped a tree out of his yard. The keepers left it alone because they wanted to encourage Francois to exhibit this natural behavior. Over the span of two weeks, he dismantled the limbs and branches and dragged them all into his den.

New Trail, New Challenges

Several years ago, the Zoo’s aged seal and sea lion pool began losing water. Rather than merely patch it up, the Zoo decided to embark on a major overhaul. The revamped exhibit, centerpiece of the new American Trail, will include four holding pools so that animals can move around, which encourages social enrichment. It will also allow animals to find a quiet spot and be alone—which, Hellmuth explains, animals need as much as people do.

The new pools will feature complex topography, including rock work and underwater arches. There will be more viewing spaces for visitors.

Creating a naturalistic exhibit doesn’t always lead to immediate happiness, however. For the American Trail exhibit, the Zoo recently acquired a raven that was previously housed indoors. Keepers and maintenance staff worked together to come up with a suitable structure to provide comfort and warmth in the bird’s new outdoor enclosure.

The bird didn’t like it. So the team reworked the structure, extending the platform on which the raven could perch. The raven still didn’t like it. The third structure was under construction when this story went to print. It included an extended roof and a heating system.

All this may seem like a lot of effort for one bird, but the Zoo makes animal comfort a priority. We humans like to have the choice of going to the movies or hiking over the weekend as a way to enrich our lives. So keepers provide different types of shells for the hermit crab. “We do it for ourselves, why wouldn’t we do it for the animals we’re responsible for?” asks Hellmuth. With the Zoo’s support, she is working to establish enrichment standards for each species in our collection.

Better for Both

Creating facilities and homes that are interactive and reflective of an animal’s wild environment keeps them healthy both physically and mentally. Keeping animals challenged and stimulated benefits zoogoers too. Asian elephant curator Tony Barthel explains, “The animals are here to connect with people, and if visitors can see the animals doing things they naturally do in the wild, enriching exhibits become an educational tool as well.”

Orangutan on the O-Line
(Jessie Cohen/NZP)

- ALLIE KILLAM and MARK TUAI were Smithsonian Zooger interns.