Hollie Colahan serves as Vice President of Animal Care at the Denver Zoo, one of the nation's premier zoos. She is responsible for supervising the entire animal care staff and keeping the institution at the forefront of animal wellness and husbandry. Additionally, Colahan is coordinator the African Lion Species Survival Plan (SSP) and is currently chair of the Association of Zoos and Aquarium's Professional Development Committee. Here is her story.
@ Denver Zoo
While attending Kansas State University, Hollie Colahan began volunteering at the Sunset Zoo because she wanted to go to vet school. “Then I found there was this whole other career out there of working on the animal husbandry side,” she remarked. “At the same time, I had no aptitude for organic chemistry so I changed majors, did an internship and later got hired at the zoo.” After graduating, she went to the Cheyenne Mountain Zoo in Colorado Springs. “I got to do a little bit of everything there as I had a position where I was basically a relief keeper for the entire zoo,” Colahan remarked. “I really liked that because I got to do a lot of things.”
@ Sunset Zoo
At this time, Colahan got hired to join the staff of Disney’s Animal Kingdom in 1998 shortly after it opened. “It was a really neat time,” she remembered. “We were starting to do things not a lot of other places were doing. We did a lot of training, enrichment and behavior research that’s common now but wasn’t that widespread then. Having the resources of the Walt Disney Company was really amazing.”
@ Disney
Colahan started as a primate keeper before getting promoted to manager of the Night Keeper Team. “The majority of their maintenance and horticulture work occurs overnight so we had to have keepers overnight to accommodate that work and look after the animals,” she explained. “We would go out on the savanna and keep an eye on the hoofstock as the horticulture team did planting.”
@ Disney
@ Disney
Colahan was also part of the opening team of Disney’s Animal Kingdom Lodge in 2001, a hotel where giraffes, zebras and a variety of African hoofstock and birds roamed savannas outside of guests’ windows. “The Lodge was such a different model as guests can see animals 24/7,” she remarked. “It’s kind of a flip of the park as it empties out during the day and people come in during the evening. We did a lot of training and husbandry with the animals inside the barns during the day and then would let them back out, which is the opposite of how you’d run the park.”
@ Disney
“One of the most interesting things was people would come and stay for multiple nights so you’d maybe talk to the same people three nights in a row,” Colahan added. “For the night staff, it was nice since we usually didn’t get hardly any exposure to guests [at the park] but at the lodge we could do keeper talks while people were around.”
@ Disney
Colahan then returned to the day shift as Zoological Manager of Primates. “I had always been a generalist but got really specialized in primates at Disney,” she elaborated. “It was really cool as it was the first place I worked with a bachelor group of gorillas. We also had mandrills, colobus monkeys, gibbons and siamangs. I also got to work with Dr. Anne Savage and the Cotton Top Tamarin SSO, and later became the international studbook keeper. The challenges of primates are pretty universal as you’re working with really intelligent animals who have a lot of needs. Anytime you work with social animals that adds a level of complexity in terms of dealing with the social group on top of the operational and individual needs.”
@ Disney
@ Disney
Disney’s Animal Kingdom was one of the first places to have a bachelor group of gorillas. “It’s a different social dynamic than family groups,” Colahan commented. “It’s more fragile and not as stable so you want to make sure you don’t do anything that sets them up not to do well together. Maintaining them until adulthood was a challenge. We had to separate them and put them together again in a way that wouldn’t cause conflict.”
@ Grayson Ponti
@ Disney
“We [also] had a complex group of mandrills with multiple males that was a challenge,” Colahan stated. “When you get a group like that, there’s a lot going on socially and you have to pay attention to who’s dominant to who. We did a fairly long-term behavioral research study on them, with the help of Dr. Jill Mellen, which was great since I hadn’t gotten to do that much kind of stuff. We tried to figure out dominance hierarchies, when aggression was increasing or decreasing and who was displacing who.” She remarked mandrills were one of her favorite primates to work with.
@ Disney
@ Disney
“With our gibbons and siamangs, we did a lot of maternal infant care training,” Colahan added. “We had a female gibbon who was pregnant and had a history of not taking care of offspring. We also had a baby siamang abandoned by their mother for the father to raise. We really tried to get those animals with their moms rather than hand raising them as that can lead to them struggling to be good parents and get into a social group.”
@ Grayson Ponti
@ Grayson Ponti
One of the most important things Colahan learned from her time at Disney’s Animal Kingdom was the importance of training. “I trained a silver back gorilla in the bachelor group who had a history of being aggressive and uncooperative,” she said. “I was assigned to be his trainer and learned so much from him. I think he’s the smartest gorilla I ever worked with.”
In 2004, Colahan moved to the Houston Zoo as Curator of Primates but soon became Curator of Carnivores as well. “It was a great opportunity to become a curator,” Colahan elaborated. “At Disney, we had a relatively small collection of primates so at Houston I had a much bigger collection to manage. I was doing less of the day to day and more of the collection management piece.”
@ Houston Zoo
@ Houston Zoo
"We had a lot of geriatric carnivores so we ended up having a lot of opportunities to change the collection,” Colahan remarked. A number of new animals were brought in while others were phased out. “I took the philosophy of taking advantage of the local climate and focusing on more tropical species,” she explained. “We got out of snow leopards and brought in fossa, clouded leopards and caracals. We started a cheetah ambassador program and handraised a pair of cheetahs. We brought in wild dogs and opened a new wild dog exhibit. We assisted the Houston SPCA with a confiscation from a guy who had a whole bunch of bears and tigers but lost his USDA license and couldn’t take care of the animals. I helped them find places for those animals to guy but we ended up taking the grizzly bears. They were quite old so we gave those guys a nice retirement for the last few years of their lives.” The zoo got a number of new primate species as well including DeBrazza’s monkeys, swamp monkeys, pied tamarins and red-tailed guenons.
@ Houston Zoo
@ Houston Zoo
During this time, the Houston Zoo was growing. “Rick Barongi had come in with a strong focus on the guest experience and conservation,” Colahan recalled. “Things were just getting started and we added a lot of talks, shows and tours. We really grew the training and enrichment program as well. The other big piece that was happening was the growth of the conservation program, which is fantastic in terms of what they support and how they message those things to the guests.”
@ Houston Zoo
@ Houston Zoo
One of Colahan’s biggest responsibilities was helping design a state-of-the-art habitat for chimpanzees. “From the time I got there, I was very involved in the chimp design, finding the animals and bring them in,” she remarked. “That took up a big chunk of my time. I really wanted as much flexibility as possible. We focused on that in the building. The chimps don’t spend that much time in the building but it has a lot of space and ways to configure animals. It lets you manage this big fission-fusion social structure you see in chimps where not everyone wants to be together all the time. They have lots of different rooms and natural light when they don’t want to be out.”
@ Houston Zoo
“Chimps are such great exhibit animals since you can house them in these large troops and they’re always doing something,” Colahan elaborated. “They’re so active, interesting and interested in people. We highlighted that with the termite mound and training room. However, at the time, the Houston Zoo was the only zoo building a new chimp exhibit. “The SSP (Species Survival Plan) was very excited to have us on board,” Colahan noted. “We talked quite a bit with Steve Ross (the SSP coordinator for chimps) and worked really closely with him. Steve had a lot of passion for getting chimps out of private hands and connected us with a couple in California who had ten chimps who had been used in entertainment.”
@ Houston Zoo
The troop adjusted to their new surroundings fairly quickly. “The chimps were fairly well socialized in small groups,” Hollie Colahan stated. “We were able to get those animals to us and it was really nice to have ten animals that all knew each other. We were able to get all ten of them together in one group really quickly.” The chimpanzee habitat opened as part of the zoo’s African Forest in 2010.
@ Houston Zoo
@ Houston Zoo
During this time, Colahan became coordinator of the Lion SSP. “When I took over carnivores [at Houston,] I started to get involved in the Felid TAG and attending those meetings,” she remarked. “The Lion SSP opened so I applied for it and got it. Lions are very popular in AZA zoos but when I started there was actually a shortage of lions. Nobody was very focused on lions since there wasn’t a big threat to them. we had all these older cats who were sterilized. In the mid 1990s, the Lion SSP started up again so they imported all these cats from southern Africa that didn’t have the breeding success they had expected. It actually took awhile to see the breeding success and there were all these older animals dying and not enough new animals to replace them.”
@ Houston Zoo
Colahan helped turn the tide and soon lion breeding was commonplace again. An important first step was getting animal care staff prepared to do introductions of recommended breeding pairs “Cat intros tend to look very violent so you have to have the experience to know if what you’re seeing is normal or cause for concern,” she said. “If you don’t know, you’ll have a tendency to shut them down. We’ve turned a corner in the last couple of years and have started to have a lot of breeding successes. I now have a list of lions I want to find places for. We’ve gotten that population to the point it is genetically and demographically healthy.”
@ Denver Zoo
Colahan is responsible for managing all the lions in AZA zoos. “One of the challenges we have with lions is contraception,” she remarked. “Because they’re social cats, we want to keep them together even when they’re not breeding. It’s a challenge to find contraception that is affective but doesn’t cause long-term harm. Also, our birth ratio is typically 50% males and 50% females so the male management piece is important. We’re trying to get more institutions to hold all male groups as related males can stay together their whole lives. We have two prides in Denver and one of them is four males.”
@ Denver Zoo
@ Denver Zoo
In 2011, Colahan moved to the Denver Zoo as Curator of Large Mammals. “I really liked Colorado when I lived here the first time and always knew I wanted to come back to this part of the country,” she noted. “When I was curator here, I had Predator Ridge (lions, hyenas and African wild dogs), cheetahs and most of the hoofstock collection- giraffes, Grevy’s zebras, camels, Przewalski’s wild horses, bongos, eland, gerenuk and okapi. We brought in Somali ass after I got here.”
@ Denver Zoo
@ Denver Zoo
However, one of the most interesting animals she managed was the fierce Cape buffalo, a species found at relatively few American zoos. “Cape buffalo weren’t a priority species for the TAG (Taxon Advisory Group) and were more focused on Asian cattle species but we have a long history with them and they’re such neat animals,” Colahan said. “Now the TAG has decided they want to grow the Cape buffalo program and we have started breeding them again. You can’t hold Cape buffalo in a typical hoofstock exhibit so you have to want to get into the species and build a habitat suitable for them.”
@ Denver Zoo
@ Denver Zoo
Denver Zoo is home to the award-winning Predator Ridge, a set of rotational naturalistic habitats for social African carnivores. “Predator Ridge is one of my favorite zoo exhibits ever and was before I worked here,” Colahan stated. “The rotational aspect is great since moving the animals around different habitats is enriching and provides flexibility in managing social animals. There are so many options in that space. We have two off exhibit yards in the back so no one gets stuck inside and everyone gets to have fresh air. The interior area works very well and we’ve successfully bred all three species in that building. The exhibit is really impactful from a guest experience standpoint.”
@ Denver Zoo
@ Denver Zoo
Predator Ridge ties in nicely with the Denver Zoo’s conservation work in Botswana. “We have a program based in the Kalahari region of Botswana where we’re working with a guy who wanted to test taste aversion,” Colahan explained. “[Taste aversion is when] you feed an animal a carcass that makes them sick so they will have a negative association with the meat of livestock. Lions would be fed beef, develop an aversion of eating cattle and focus on wild prey instead. There’s a fair number of challenges in that region with lions coming out of the reserve and killing cattle so the wildlife department ill catch those problem lions and transport them somewhere else in the reserve. We put collars on them to see if they are encountering issues.”
@ Denver Zoo
@ Denver Zoo
In 2014, Hollie Colahan was promoted to Vice President of Animal Care at the Denver Zoo. “Being a curator for me was the best zoo job since you still get to do animal stuff and be a little hands on but also get involved in bigger picture stuff,” she reflected. “I was worried coming into a VP position would pull me further from the animal side but I really enjoy being part of shaping the direction of the Denver Zoo as a whole and being part of the time that guides where the Denver zoo goes in the future. I have 120 people in my department and try to find ways to make it easier for them to do their jobs, which has been very rewarding.”
@ Denver Zoo
@ Denver Zoo
“I think a lot of the zoo’s focus going forward is getting better at telling our conservation story,” Colahan articulated. “Zoos have been responsible for bringing animals back from extinction in the wild but we have people who still think we’re just here for entertainment. Zoos will continue to make that special one on one connection with animals and they’re in a very unique position to inspire people to do something for animals in the wild. At the Denver Zoo we have a longstanding field conservation program and we’re sharing that with our guest. We make sure when someone sees lions at Denver Zoo, they learn about what we’re doing for lions in the wild and what they can do to help lions. We’re also very focused on sustainability, which is a great message as to what people can do to save water and energy and use less plastic.”
@ Denver Zoo
@ Denver Zoo
“For me, what makes the Denver Zoo special is the people,” Hollie Colahan concluded. “I haven’t worked anyplace that has had the level of collaboration in terms of how closely my team works with the guest experience team, the education team and the marketing team. They have an interest in each other’s goals. We have a group of people that’s very focused on everybody’s success and prioritizes giving our animals good care. That helps all the other amazing things happen.”
@ Hollie Colahan
