Enriching: Miller Park zookeepers keep animals engaged and energized
Unlike young children on a car ride chanting "Are we there yet," zoo animals can’t tell you when they’re bored to tears. Some of them don’t even have tear ducts. It’s the job of zookeepers to make sure the animals in their care stay active — mentally as well as physically.
During a recent midday trip to Bloomington's Miller Park Zoo, two otters, Tallulah and Rhett, eagerly bounced around their enclosure, almost impatiently looking around.
“You can see right now they are anticipating there is staff coming. They know. They are super excited and waiting for their caregivers to show up for a training session,” said zoo director Jay Pratte.
The training blends with food for the otters, as it does for a lot of species. Wendy Klessig is the most senior zookeeper at Miller Park. She has been there more than two decades and used bits of fish to is get the otters to twirl around, stand up, and do other things.
There’s a practical purpose to that, said Klessig. Having Tallulah and Rhett stand up lets zookeepers see their bellies and whether they are pulling out tufts of fur. That’s a possible sign of stress. If so, staff will try more enrichment.
In a room behind the scenes, zookeepers work on more extensive medical behavior.
"We’ll have them participate by getting onto a scale so we can check and monitor their weight. I’ve done advanced otter training in the past, and we’re working on it here, where they will go into a PVC tube and allow us to do more physical inspections. Otters can be X-ray and injection trained,” said Pratte.
Other kinds of enrichment are simply for the mental well-being of the animal.
“We’ll give them ice blocks, frozen fish, different things that take them more time to interact with to really challenge them to use their little otter powers, their natural behaviors," said Pratte. "It’s just one thing to throw a toy in and say, oh they can play with it. But what do we want them to do. Do we want them to smell it? Do we want them to manipulate it?”
That need for mental exercise is true as well for the heritage breed of pig, Mule Foot Hogs, at the zoo. Two of them are wallowed in muck happy as a pig in…well anyway…they tossed around PVC pipes that had food stuffed into the ends. It’s a variation on something used for many animals, a so-called puzzle feeder.
“She has figured out that if she pins it in the corner and then flips it around, it doesn’t go all over. She is being very clever about how she manages this puzzle feeder. Instead of having to chase it all over the yard, she’s pinned it into the corner. She just has to roll it with her snout and things fall out. She’s basically being lazy about it, but she’s being efficient,” said Pratte.
Pratte said enrichment activities work best when they let or prompt the animals to do the same things they do in the wild — in the case of pigs — root around and snout things out as they forage.
“They’re having to use their whole bodies. They’re getting exercise. They’re using their muscles and their doing what pigs do. They would dig. They would root around. They would tear things apart. They would think, because pigs are a really intelligent species,” said Pratte.
Over at the bird enclosures, a couple of cockatoos perch, preen, and offer a gimlet side-eye to the microphone. They’re interested and would clearly love to get their claws on it.
Zookeeper Julia Elie said one of the birds is Henry, a Salmon Crested Cockatoo. Henry has been a zoo resident 2008. He’s 27 years old.
“He likes to say good boy. He loves being told that he’s a good boy. He says it back. And he starts hopping around and he gets his feathers up, all excited,” said Elie.
Parrots and cockatoos are ridiculously social creatures. In the wild, they can flock in the hundreds. A recent study found that parrots simply love video calling other parrots using tablet computers. They even like to choose which other parrot to get on the line. Elie said it is very obvious when these birds are stimulated. They bounce. They respond to zookeepers. And they are verbal, sometimes loudly so.
They also will try to get away. And their beaks can snap branches. You can probably guess how the zoo’s Black Cockatoo, Chompers, got his name.
“He gets some hanging toys. He loves to destroy as all big birds, cockatoos, parrots like to do. Today, he got some mulberry browse which he was very excited about. He was ripping apart the leaves, shredding them,” said Elie.
In the wild, that destruction of plants, bark, and branches helps the birds find food, nest and explore their environment. In the winter when there are no fresh branches to chew on, Elie said they give them paper, cardboard boxes, and paper bags to rip apart.
If parrots can’t engage in those natural behaviors — nesting, social interaction with other birds or humans, and destructive, investigatory behavior — they may turn to self mutilation by pulling out their own feathers.
Most of the parrots you see in zoos have been donated, basically left by people. Often, Pratte said, parrot owners don’t know what they are doing and what is wrong and end up giving bald birds to zoos.
“Then those animals require extra care. They require that we try to understand why they have these issues. We try to get to the root of it and bring out more natural behaviors. But like with people, these can be really entrenched and require a lot of time to work through,” said Pratte.
Some birds of the parrot family can live up to 100 years.
Large cats such as lions, tigers, and leopards need activities that use their physical skills since they spend a lot of time hunting, stalking, and exploring their territory. Here, too, puzzle feeders are a staple that uses feline abilities.
“Maybe a covered garage door spring, so that when they pull, they have to engage all of their muscles and claws. They dig in. There’s almost some fight and struggle there to develop all those muscles and provide more of an experience as opposed to knocking something around,” said Pratte.
Big cats also need multiple environments, a place to lie in the sun, groom, and depending on the species, bathe.
Another kind of animal that needs enrichment at the Miller Park Zoo is the family of five Dwarf Mongooses.
Zookeeper Austin Ahlert said since they are smart and social they need more enrichment challenges than the average animal.
“Inside their exhibit, they have a plastic tunnel they can crawl through. I have given them play pit balls in the past and put them inside that tunnel. They responded pretty quickly to it. They were pushing them all through the tube to display some curiosity habits,” said Ahlert.
That’s a pure play challenge. Ahlert also gives the mongooses a food puzzle — a honeycomb-shaped tray with depressions in it. Some slots have food. Some don’t. And the plastic balls hide some of the food, so the mongooses have to sniff it out and move the ball too get the goodies.
There is real science behind designing enrichment activities for the animals in the zoo. There’s also creativity.
Pratte said zookeepers have to make sure challenges are safe and sized right for big cats and small mongooses alike. The difficulty varies. Did they get all the food? Was it so easy they got everything in 3 seconds? Pratte said animals change cognitively as they age as well, and zoo staff have to take declining abilities into account. Younger, more mobile animals need more challenges.
There are lots of resources used to develop enrichment activities. Zoos share what works and what doesn’t for certain animals. And the scientific community contributes, too. An ethogram is a general list of behaviors that are recognized for a species.
“Sometimes you can work off ethograms. Sometimes it’s papers or articles. It might be a National Geographic special that triggers you. I’ve come up with enrichment ideas based on a German translation of an African-crested porcupine paper from 15 years ago about how they forage in potato fields. There are always different sources. And then it’s taking an approach of …how can I recreate that effect for these animals,” said Pratte.
There may even be government regulation on how much enrichment reputable zoos must do. For instance, the U.S. Department of Agriculture licenses sanctuaries to have primates.
“You are required to have provide complex primate enrichment on a daily basis and you also have to record and demonstrate you have provided that enrichment. You have logged you are assessing the success of that program, that they have appropriate social and cognitive challenges,” said Pratte.
He said animals are truly a marvel. Some seed-eating bird species can hide food in thousands of locations and remember each spot. That capacity suggests certain enrichment activities as well.
Ithas worked on a panda study in a peer-reviewed psychology magazine determining how long pandas remember where something was. It was based on the location where they saw light, and then when the light went off, after how much of a delay could they remember where it was. It was complex.
“It took about a year and a half to two years to teach them to interact with the device because it wasn’t just push this button, it was a concept. Not only do you have to push the button where the light is, you have to push the button where the light was,” said Pratte.
What they found was the male was more tolerant, he said. The female learned the process better, retained more and could deal with a little bit longer delay.
Pratte said zookeepers should never stop learning about animals and their abilities. And as Miller Park Zoo staff train and develop projects by owning their own areas, he said they may be able to pair up with universities for studies, making the animal activities even more robust and the animals healthier and happier.