Bandar the tiger eating a bloodsicle
Bandar the tiger eating a bloodsicle Credit: All photos Darrow Montgomery

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Bandar the tiger gorges on his blood popsicle in private. Animal keepers at Smithsonian’s National Zoo attach an oxtail to the frozen treat so he can clamp down on it and drag it into the bushes. Commissary manager Bill Clements sources the blood from a butcher at Eastern Market. 

“We’ll freeze it up and mix some gelatin in to make it more viscous and more fun to lick,” Clements says. His team molds ground beef into stars and affixes them to the sides making it look at once glorious and grotesque. 

A bloodsicle is a lavish snack for the lions and tigers. Their usual diet consists of ground beef from Nebraska, rabbits, and beef femur bones. Occasionally they’re treated to a carcass feed, as gnawing on large portions of a whole animal best emulates how they eat in the wild. The meat is harder to break down, so it keeps their facial musculature well conditioned and their digestion systems revved up. 

Though not as gory as the goat scene in Jurassic Park, carcass feeds are a bit controversial, according to Mike Maslanka, the senior nutritionist and head of the department of nutrition science. “We waver on carcass feeds,” he says. “We have to do it in a thoughtful way and educate people who come through the zoo—we don’t want to offend someone’s sensibilities, even though they’re seeing carnivores doing what they do.” 

Whenever there’s a carcass feed, Maslanka or another zoo nutritionist posts up outside the exhibit like a chaperone at a PG-13 movie to answer visitors’ questions. Yet save for special eating events like these, and a short meet-a-nutritionist demonstration each Wednesday morning, members of the zoo-visiting public rarely meet the people who spend their working hours lovingly keeping 350 species well-fed and nourished.

“The whole concept of feeding a zoo doesn’t cross anyone’s mind,” Clements says. “People come through and say, ‘We’ve never considered how all that happens. We figured you threw a couple of carrots in the cage.’” Rather, those carrots are “sourced, paid for, washed, weighed, evaluated for quality, and portioned out appropriately,” according to Clements.

Commissary Manager Bill Clements

Feeding 1,200 animals, from anemones to elephants, is a complex, integral, and utterly fascinating facet of life at the zoo. At an annual operating budget of $1.2 million, it is also the zoo’s biggest expenditure. And the keepers use food for far more than sustenance, making the operation even more complicated. Food serves as a training reward; a vehicle for giving medication; and a bonding mechanism  for animals and keepers. 

Members of the zoo’s food team navigate hidden passages to reach behind-the-scenes areas where they filet small, pungent fish for squeaking otters. Or they spend their days in the belly of the big cats exhibit sprinkling edible glitter on ground beef so that when it comes out the other end, they can test the cats’ hormone levels. Then there’s the back room of the the commissary, where Clements might be sawing through a steamship round of beef for Murphy the komodo dragon. 

Edible glitter on ground beef for the big cats

The 23,000-square-foot commissary is the heart of the operation. It sets the National Zoo apart from other zoos, where food is more commonly prepared at individual exhibits. “Each kitchen has its own disasters going on,” Clements says of other zoos. “Favorite animals get more. Animals are overfed. We want to rule all that stuff out.” 

In contrast, the National Zoo’s commissary is centralized, meaning keepers prepare all meals under one roof before providing room service to every exhibit from the Asia Trail down to the kid’s farm all before the first visitors enter at 8 a.m. 

“It’s like cooking for Oprah down here,” says Clements. “Everything is weighed out to the gram.”

The federal government considers Clements and his team of ten commissary keepers to be essential personnel. The animals must eat 365 days a year. During a snowstorm, keepers and nutritionists are at work. They were there, too, during the 2013 government shutdown when all Smithsonian properties closed to the public. “You’d walk through the zoo and everyone was up front looking at you, barking at you,” Clements recounts. “They missed the people so bad. It was really cool.”

Clements started at the zoo in the late ’90s as a conservatory gardener and animal keeper, and worked there three years before leaving to take a job at Costco, where he stayed for a decade. Then he returned to the zoo, this time in the commissary, where he has now been for more than six years. 

His time at Costco proved to be a boot camp for buying in bulk. Clements is responsible for keeping the commissary fully stocked to feed a city of animals. They need 700 pounds of bananas a month and blow through seven tons of leafy greens annually. 

In the freezer

A tour of his massive “office” reveals a living room-sized freezer set at 15 degrees below zero. It held Bandar’s bloodsicle and Bei Bei’s birthday cake. Ice flakes land on your eyelashes as you gape at the mound of fish bound for the seals. Next door is a second sub-zero freezer that looks like a frozen-over pet store, its shelves lined with mice, rats, and rabbits.

Another room in the sprawling warehouse looks and smells like the dog food aisle at the grocery store. But the boxes of biscuits and canned food are for primates, not puppies. Nearby the commissary stocks cookout condiments. Keepers use ketchup and mustard as training rewards.

Turn the corner to catch a flurry of activity in the diet prep kitchen, lit like a doctor’s office and just as clinical. There, keepers make hundreds of meals daily. “Sometimes I cut grapes into quarters for the smaller animals,” says Mike Kirby, a commissary animal keeper. “Right now I’m working on a diet for a white-cheeked gibbon who is very old so she gets a special diet.”

His colleague Coral McDonald is at another station preparing 55 diets for the small mammal house. The stack of plastic containers holding meals is as tall as Marcin Gortat. “I’m working on a dusky titi,” she says. “He’s ancient so he has to have specific-sized pieces of things he can grab because he has arthritic issues.” 

Small mammal house diets

Not only do nutritionists tailor diets to each species, but some individual animals have their own diets based on their ages and abilities. It’s like they’re running a cafeteria for a nursery, an elementary school, a middle school, a high school, and a nursing home all at once. 

On top of feeding 350 on-premise species, plus an additional 20 species at Smithsonian’s 3,000-acre Conservation and Research Center in Front Royal, Virginia, the commissary is prepared for the unexpected. One August morning, for example, a 70-year-old elephant stopped drinking, prompting Clements to drop his to-do list and head to Costco to pick up 25 gallons of coconut water. The errand allowed the elephant to stay hydrated. 

“There are a lot of curveballs,” he says. “Like the seal pup last year that was getting salmon oil and heavy whipping cream by the gallons.” Local grocery stores have started to recognize Clements’ face. “If they see Gatorade, they’ll say, ‘Is this for the elephant?’” 

According to Clements, the National Zoo also differentiates itself from other zoos through the quality of meat, fish, fruits, and vegetables it feeds the animals. The commissary cooks are as proud of their carefully sourced ingredients as a chef at a farm-to-table restaurant boasting about heirloom tomatoes he plucked that morning.

“All of our meat is from the human food chain,” Clements says. “We don’t give any diseased or downed animals, but a lot of zoos will. If we can’t eat it, we’re not feeding it out.” The rabbits, rats, and other small animals given to larger predators are raised the same way chickens and pigs are for people—at U.S. Department of Agriculture inspected facilities. The shrimp the red-bellied piranhas eat in the Amazonia exhibit are chemical free. “As good as Whole Foods,” quips Clements.

Murphy the komodo dragon

The same goes for produce. “Our guys will inspect it just like any restaurant,” Clements says, as a chorus of crickets chirp away in cardboard boxes on the loading dock. When crates of fruits and vegetables arrive, a team carefully combs through romaine lettuce, mangoes, tomatoes, and kale. 

“We’re feeding endangered animals here,” Clements continues. “We don’t want to risk second-rate leftovers from a vendor to save a buck. We don’t want a moldy apple to take out a panda bear.”

While commissary keepers prepare and distribute food, a dedicated team of clinical nutritionists prescribes what the animals eat in the morning, in the evening, when they’re sick, and when they’re preparing to breed. 

“One day I could be working on bird diets, the next day large cat diets, the following day on how to properly gut-load insects to feed to a reptile,” says Erin Kendrick, a clinical nutritionist who has been with the National Zoo for more than five years.

“Gut-loading” is a process that changes the nutrient profile of insects before the reptiles get to eat them. Feeding a cricket specific vitamins and minerals in advance makes it a more complete nutritional package. 

“We’re focused on increasing the calcium and phosphorus and looking into increasing carotenoids,” Kendrick explains. “All animals require calcium and phosphorus in the appropriate ratio for proper bone growth and health.” Carotenoids are plant pigments that provide antioxidants and help with immune system health. 

This strategy speaks to the zoo’s greater doctrine of building diets for its animals. Many think Kendrick’s job is to match what animals eat in the wild with what they eat at the zoo, but that’s impossible. Instead, Kendrick plays matchmaker with nutrients.

“We have to find a balance between the nutrients we believe they require and the ingredients we have available to us,” Kendrick says. “No way could I ever foresee us having commercial-level ground antelope meat. It doesn’t make sense financially or from a conservation standpoint.” Instead of antelope, the lions and tigers get ground beef that arrives at the zoo already supplemented with bone meal, vitamins, minerals, and fiber. 

Making these determinations is an onerous, scientific pursuit. “The information we have about wild diets is relatively limited because first you have to identify what they eat, then you have to identify how significant a certain thing might be to the animal,” Kendrick says. “Once you know that information, you can do a nutritional analysis and figure out what nutrients are in there.” 

Take fruit. “Wild fruits are low in sugar and starch and high in fiber and protein,” Kendrick says. “Our fruit, comparatively, is high in water and sugar and lower in fiber and protein. They’re fruit, but they’re very different nutritionally.” 

Even animals categorized as frugivores benefit from eating leafy greens and vegetables instead of what you find in the fruit section at the local Giant. Think bell peppers instead of melons. That said, keepers still offer domesticated fruits, just in more limited quantities.

The tricky part of Kendrick’s job is that the animals must desire their diets. “I can formulate a diet that has the most ridiculous items in it and it will be balanced, but if the animal doesn’t eat it, it doesn’t help me,” she says. Red pandas are some of the most unpredictable eaters at the National Zoo. They’re ravenous one day and refuse to eat the next. “It can be frustrating, but that’s part of the fun,” Kendrick says. 

The zoo has just over a million dollars to work with to feed the animals, so workers use some ingredients across multiple species. Consider that American alligators, bobcats, and maned wolves all eat rats and mice. “People we talk to are surprised it’s so cheap, but given the fact that our budget comes from the federal government and that comes from taxpayers, we try to be as responsible as possible,” Maslanka says. 

Palpating a skunk

The nutritionists conduct body condition scoring evaluations to assess whether their diets are working. You’ve seen this process at the veterinarian’s office, when the doctor runs her hands over the bony processes of your pet to determine if your four-legger is getting chubby. Kendrick does the same thing. 

“Everyone’s got a spine, shoulders, and hips. There’s just varying degrees on how easily I should be able to feel them,” Kendrick says. She scores zoo animals on a scale of one to nine, with five being ideal. Nine is obese; one is emaciated. 

Sisters Clementine and Trixie still have some work to do in The Biggest Loser, skunk edition. While palpating Clementine, Kendrick finds the skunk’s ribs generally, but can’t discern each bone. After the full body massage, she scores Clementine at a seven, down one from her last exam. Trixie comes in at a six. Kendrick ultimately keeps the pair on a diet and encourages the small mammal house keepers to let the skunks frolick in a back room to burn calories.

Adding another layer of difficulty, ideal scores vary from species to species. “We get a lot of feedback on our cats being thin,” Maslanka says, explaining that even the naked eye can make out their spines, hips, and ribs. “It’s an education process. They’re not supposed to look like house cats at home. They’re supposed to be slight.” 


Having a centralized commissary allows keepers more time to devote to animal care. At the small mammal house, it only takes them two hours to transfer pre-prepared food into stainless steel pans, as opposed to doing all of the chopping on site. “Before the [centralized] commissary, it took eight hours,” says small mammal house assistant curator Kenton Kerns. “That’s huge.”

Kerns and his colleagues devote a significant portion of this borrowed time to “enrichment.” The zoo considers these mentally and physically stimulating activities, which often involve food, just as critical to animal welfare as preparing nutritionally balanced diets.

Introducing a toy, exposing an animal to a novel scent, making subtle changes to an animal’s habitat, and adjusting the way they feed an animal to coax it into behaving like it would in the wild are all forms of enrichment. The National Zoo received the 2017 Lee Houts Advancement in Enrichment Award from the American Association of Zoo Keepers for its efforts and creativity in this field.

City Paper dug into the daily routines of three species—giant pandas, red-ruffed lemurs, and Asian short-clawed otters—to show how the commissary, department of nutrition, and keepers put their ideas into practice. 

Panda Gourmet

Giant panda waiting for bamboo

Pandas are pickier than a toddler on a chicken-fingers bender when it comes to bamboo. “No one has been able to break the panda code of why they like some bamboo and why they don’t like other bamboo,” Maslanka says. He speculates that it’s either the maturity of the bamboo or the soil chemistry where the bamboo grows. 

Moisture is definitely key—panda keepers store bamboo in a special shed that resembles the produce section at the grocery store. Misters fire at full blast, keeping the long green stalks looking dewy. 

Pandas are obligate bamboo eaters, meaning that’s all they eat outside of small helpings of biscuits. Keepers offer each panda at least 100 pounds of bamboo per day, spread across multiple feedings. In the summer they munch on the leaves, while in the winter they crave the stalks. 

Given this volume, the zoo tries to secure its bamboo for free from large, privately owned tracts of land within an hour’s drive, such as the back of a golf course. And, there’s an “ace in hole” patch of bamboo on zoo property in case of a major snowstorm or other travel-restricting emergency.

Animal keeper Mike Kirby

“Most people who call have little quarter-acre yards with a corner of bamboo on it and they’re like, ‘Come cut it but don’t step on my roses,’” Clements explains. “We want someone who has 12 acres who planted bamboo on the back corner and forgot about it for five years.” 

The zoo keeps its prime patches of bamboo “low key,” according to Clements. “We wouldn’t want a panda hater to go out there,” he says. “You have to worry about all that stuff.” To keep track of where they cut, the commissary maintains a secret dossier of Google Earth images annotated with comments about which swatches the pandas find delectable and which they’ve eschewed.

Pandas get their first meal around 7:30 a.m. Mei Xiang, Tian Tian, and Bei Bei know it’s almost breakfast time when keepers Jenny Spotten and Shellie Pick arrive. While they set up an edible scavenger hunt in each animal’s “yard,” the pandas are in the enclosed rooms of their individual habitats, excited to get their first taste of bamboo. One bear sticks its nose, then its paw, then its other paw through a brick-sized hole. 

After the bamboo is in position, the keepers prepare the pandas’ enrichment activities. First, they load up doughnut-shaped “puzzle feeders” full of biscuits and hang them from branches. The pandas have to climb onto rocks and knock them down piñata-style to get at the food. Each feeder has a hole in it, and the zoo’s two adult pandas have wildly different strategies to get the biscuits out and into their mouths. 

Giant panda Mei Xiang

Mei Xiang finds the hole, lies on her back, and rotates the ring until biscuits fall out onto her belly. Tian Tian knocks the feeder against walls and tree trunks hoping the occasional biscuit escapes.

Biscuits won, it’s time to move onto scent enrichment. “We’re doing fennel today,” Pick says, as she rubs the anise flavor onto one of the logs in Tian Tian’s habitat. They’re exposing the bear to scents he wouldn’t normally encounter to see his reaction.

“There’s a panda behavior called scent-anointing where they take a scent and rub it all over themselves,” Pick says. “Mei Xiang had a field day with coconut and Tian Tian likes bubbles.” Every smell has to be approved by the department of nutrition and the veterinarian. Some ingredients are toxic to pandas, including coffee and onions. 

Lemurs and Doers

Ashton Ball hand feeds a red-ruffed lemur

Red-ruffed lemurs—who look like mutant Teddy bears with burnt sienna colored bodies and black bushy tails—start the day with a petite treat. “The commissary sends grapes that we feed to every single primate in the morning,” Kerns says. “That way if one of them gets sick and we need to give them medicine, they’re like, ‘Oh, that’s my daily grape.’” 

Keepers slide pills into grapes, just as pet owners bury medicine in cubes of cheese. It’s not a perfect system. “Sometimes the vets prescribe medicine that’s so terrible tasting that they go off grapes for a week,” Kerns says. “That’s when we talk to Erin [Kendrick] about using something spectacular to get the medicine into them.” 

At a daily hand-feeding session on a Thursday, the lemurs are as grabby as fresh-faced Washingtonians at a company-sponsored happy hour. They swipe at bananas, papayas, and mangoes and leap from branch to branch, but eventually settle down to receive fruit from staffer Ashton Ball in sequence.

“Any time we can get them to come over to us, it makes training easier,” Ball explains. She uses food to entice lemurs to step on a scale. Weight is indicative of an animal’s overall health. “This is really important to us because animals don’t tell you when they’re feeling sick,” Kerns says. If they show signs of weakness in the wild, predators will pick them off first.

The small mammal house where the red-ruffed lemurs live is one of the areas of the zoo with the most robust enrichment programs. In the staff-only zone, just off a small kitchen, there’s a room not unlike a children’s daycare. Keepers stock cubbyhole after cubbyhole with toys and puzzle feeders, and they have a ball pit. Watching animals hunt for mealworms in a kiddie pool of plastic rainbow balls begs for an Instagram Boomerang. 

“We do scent enrichment, play with mirrors, put their food in water so they have to fish it out,” Kerns says. Each species gets a new enrichment activity every day for 30 days before the cycle starts again. Zoos across the country share enrichment ideas on social media. That’s where Kerns got the idea to put a bouillon cube in a bubble maker. It spits out beef flavored bubbles—a culinary trick equal to what Chef José Andrés pulls off at minibar, his D.C. molecular gastronomy restaurant.

Since most toys are made for house pets, the zoo keeps an Amazon wish list that enables the public to purchase puzzles and more for the animals. That Thursday the lemurs got their hands on “holly rollers” that could have just as easily entertained a house cat. To use them, keepers stuff crumpled paper towels full of insects into the balls, which have generous holes.

“The [red-ruffed] lemurs are into anything,” Kerns says. “They’ll rip apart puzzle feeders in ten minutes. Paper towels will be strewn all across the exhibit.”  

How The Otter Half Lives

Asian short-clawed otter

Usually an empty animal habitat is disappointing for zoo visitors, but if you visit the Asian small-clawed otter exhibit and don’t spot the sleek little creatures, you could be in for a show. The otters might be rolling all over each other in their private indoor pens while keeper Mindy Babitz strategically scatters food in their outdoor exhibit.

On a summer afternoon, Babitz flings frozen mussels and clams in the stream, goes back inside, and releases a group of otters. They bolt single-file through a series of narrow glass shoots before darting into their habitat like the Racing Presidents entering the field at a Nationals game.

A crowd of visitors greet the otters with shouts of “cold, colder!” as they flash to corners of the habitat far from where the food hides in plain sight. Then finally, “hot, hotter, hottest!” as the otters find the chilly bivalves that demand ten minutes of strained effort to crack open.

The members of this family of otters are named Chowder, Pickles, Peaches, Turnip, Olive, and Rutabaga. But then there’s Kevin. He’s the one with the dot on his nose, but no one can say for sure how he got the lone human moniker. 

Unlike most animals at the zoo that feed once or twice a day, otters eat every two hours on account of their high metabolism. Babitz says they nosh on a variety of fish, insects, and small animals in the wild, which translates to a zoo diet of beef, canned cat food, cat kibble, crickets, mealworms, and a variety of fish. “Smelt is their favorite, but they get live crayfish, and sometimes we feed them larger fish like herring,” she says.

The otters know when it’s time for enrichment. As Babitz readies the frozen mussels and clams mere feet away from their pens, they squeak like chew toys. 

“We want them to use natural behaviors by finding and processing food like they would in the wild,” Babitz explains. “They have to use species-specific behaviors to break these open.” Keepers collect the shells post-meal and send them to the Oyster Recovery Partnership in Annapolis so they can be recycled and used to restore reefs.


Red-ruffed lemur

A message painted on one wall of the otherwise-stark commissary says, “Together, We Save Species.” Conservation is the National Zoo’s raison d’être. Clements says it’s why he left Costco and returned to the zoo. 

The commissary and the nutrition teams work tirelessly in the background to set the standard for what animals should look like and act like when they’re healthy. Most zoo visitors will never encounter them in the wild. Everything from slipping lemurs pills in grapes when they’re feeling sick to providing the big cats with the occasional half calf to shred is part of the overall mission. 

“Most people who come to the zoo have no idea we exist and leave not knowing we exist, but hopefully they see the fruits of our labor every day, which is the animals looking good,” Maslanka says. “That’s our contribution to species conservation. It’s a badge of honor.”