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Heavy metal shredders

Posted by: Kirsten Pisto, Communications


Visayan warty pig at Oregon Zoo. This species of wild pig is coming to Woodland Park Zoo in May. Photo by Ryan Hawk/Woodland Park Zoo.

This summer, two species of wild pig are arriving at the zoo—African warthogs and critically endangered Visayan warty pigs—so we’re gearing up for some majorly pig-worthy new exhibit spaces. The warthogs will move into the African Savanna biome in the former wild dogs exhibit, and the Visayan warty pigs will have a new home in the Elephant Forest exhibit near the elephant pool.

Fencing surrounds the new Visayan warty pig space as the exhibit crew installs gates, watering holes and a mud pit for wallowing.

That means a lot of grinding, buffing and roughing is needed to get these new spaces in order. You might not know it, but many of our exhibits are designed and built with our own in-house expertise right here at the zoo. The process starts with animal management and projects staff teaming up to design a safe and naturalistic home for each new animal, and then our exhibits crew takes over.

The exhibit shop includes a giant blackboard for drafting out ideas and drawing designs. A lot of creativity and outside-the-box thinking goes into each and every project.

Our exhibits crew is made up of a team of highly skilled welders, sculptors, painters, carpenters, designers, drafters, builders, and artists. Although many of them specialize in one specific craft, all of them have to be extremely creative and resourceful to get the job done. Let’s just say that if there were a tree house competition, you would definitely want our exhibits crew on your team! They have to create beautiful exhibitry that is not only safe for the animals, but is durable and weather resistant. Oh, and it has to be green: meaning it uses sustainable materials derived from local vendors if possible.

The exhibits shop is located at the heart of the zoo, hidden from view, but central to the upkeep of our bioclimatic zones.

The exhibits shop has a carpentry/woodshop, metal shop, paint center and a large backyard for tackling projects too tall to fit inside. Most of the work is done at the shop, but a lot of the finishing details are done in the exhibits, such as painting and installation. The team works closely with animal management, projects and horticulture to ensure that each exhibit mimics the natural landscapes of that biome.

Here, you can get a sneak preview of the Visayan warty pigs’ new wallowing hole near the south side of the exhibit. Shaped concrete creates a natural enclosure for the pigs as well as a little place to nap in the afternoon. Tire tracks are seen here, but soon you will see lots of tiny hoof prints!

For the Visayan warty pig exhibit, that means creating a densely forested landscape, similar to the Visayan Islands in central Philippines. In the wild, these pigs inhabit primary and secondary forests (from sea level to elevations nearly a mile high) as well as degraded areas of invasive grasslands (if enough dense cover exists). Our crew is creating unique spaces for these three little pigs; resting hollows, watering holes, and wallowing areas. Their new exhibit will also reflect deforestation, including slash and burn piles, which are scattered across the region.

Detail of a gate which will be installed at the Visayan warty pig exhibit. There will be 12 gates for these three little pigs.

The exhibit team has to create twelve gates for the Visayan warty pigs alone. The fencing and gates are an important aspect of any exhibit, allowing keepers quick access to the animals, but also creating representational fencing that blends into the scenery. Woodland Park Zoo has been a leader in creating exhibit spaces that appear to have little or no barriers between the visitors and the animals. We do this partly by camouflaging trellis and using natural looking material to construct enclosures. This gives both our animals and our visitors a more natural view!

Bill cuts strips of lathe, commonly used for plaster walls, which are then wrapped around the steel gates you see in the foreground.

Here’s the inside scoop on the process. Lathe—commonly used for plaster walls—is secured around stick shaped steel rods like these…


Then the exhibits team will cover the entire thing in a high fiber, ‘special zoo mix’ concrete. The concrete cures in about 4-5 hours and will then be painted to match the natural sticks and vines in the exhibit. The gate sections will be covered in an epoxy, instead of concrete, making them much lighter to open and shut easily.


The epoxy dries in about three hours. That means the staff has about a two-hour working period to add in the details. They use special polyurethane molds, above, to press into the sticky epoxy to create distinctive textures. Resins are used to cast decorative millwork and architectural elements. Here you can see the various molds for different types of bark. Polyurethane is also used to manufacture hoses and skateboard wheels as it combines the best properties of rubber and plastic, durability and flexibility.


The gates and fencing, once painted and finished, will blend right into the exhibit. Here, you can hardly tell where the structural elements of our exhibit meet live plants! We call on the skills of our exhibits experts to create natural habitats that meet the needs of each creature. Quite a change from the old square cages once seen in zoos, our animal containment allows residents to explore a spacious landscape which resembles their natural habitat.

Attention to detail is key. Realistic and detailed rockwork, such as this path near jaguars, replicate the textures and colors of the rocks, lichens, moss, roots, stumps, logs, and leaf and footprint impressions found in the wild. We also paint special murals and backgrounds in many of the viewing areas.

Our exhibits team uses both conventional and unconventional materials to replicate and enrich each space that they assemble. To ensure a safe habitat for each resident, a deep understanding and study of the animals being placed into the exhibits is a requisite. Our exhibits crew is a big part of what makes this zoo so special. Each biome is designed to engage zoo visitors, helping them to better understand wildlife and the challenges of conservation and sustainability.

Take a good look at this gate work. When the Visayan warty pigs debut on May 5, you can visit their new home and see if you can find this same piece once it’s installed on exhibit. Good luck, it will be a lot harder to find once it’s finished!

Next time you visit, be sure to pay attention to the details; it’s amazing how much work goes into each and every exhibit. You can check out the beautiful work our exhibits crew does at the new Visayan warty pig and African warthog exhibits which debut on May 5!

All photos by Kirsten Pisto/Woodland Park Zoo unless otherwise noted.

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