Denver Zoo Conservation Alliance is an nonprofit zoological garden and conservation organization located in City Park of Denver, Colorado, United States. Founded in 1896, it is operated by the Denver Zoological Foundation and funded in part by the Scientific and Cultural Facilities District (SCFD). Its other sources of funding are ticket sales and private donations. It is the most visited paid attraction in Denver.
Denver Zoo was started with the donation of an orphaned American black bear. With the construction of Bear Mountain, it became the first zoo in the United States to use naturalistic zoo enclosures rather than cages with bars. It expanded on this concept with Primate Panorama, featuring huge mesh tents and open areas for apes and monkeys, and with Predator Ridge, which has three separate areas through which animals are rotated so that their overlapping scents provide environmental enrichment. Toyota Elephant Passage, which opened on June 1, 2012, is divided into five areas for rotating the various species.
Denver Zoo is accredited by the (American) Association of Zoos and Aquariums (AZA) and American Humane and is also a member of the World Association of Zoos and Aquariums (WAZA). The zoo achieved ISO 14001 certification in 2009, was given the first AZA Green Award in 2011, and was named the "Greenest Zoo in the Country" at the World Renewable Energy Forum in 2012. In 2015, it was re-certified for ISO 14001 and achieved OHSAS 18001 certification, becoming only the fourth zoo in the world to get both certifications.
History
Early years Denver Zoo was founded in 1896 when an orphaned American black bear cub named Billy Bryan – short for William Jennings Bryan, after the contemporary American politician – was given to Mayor Thomas S. McMurray as a gift. McMurray gave the hard-to-manage cub to the keeper of City Park, Alexander J. Graham, who started the zoo with this animal. Other animals at the young zoo included native waterfowl at Duck Lake, native prairie dogs, pronghorn antelope which roamed the park, and a flock of Chinese pheasants, which later populated the eastern plains of the state.
As this collection grew, the newly-formed park board continued to focus almost exclusively on acquiring native animals, with a notable pheasant collection and rhesus macaques as the exceptions. Some of the most popular animals at the park were large herds of bison and elk.
In 1905, a population of red squirrels was added to the zoo's collection; this population grew rapidly and decimated the bird population at Duck Lake. A plan to shoot the squirrels was scrapped when citizens protested. Instead, as many squirrels as could be caught were sent to the Denver Mountain Parks.
Mid-20th century
The zoo was a motley menagerie until 1906, when Mayor Robert W. Speer declared that the zoo's "[p]rison bars can be done away with" in favor of "concrete rocks, waterfalls, trees, etc." Speer hired the city's landscape architect, Saco R. DeBoer, to draw up the plans for his renovation and appointed Victor H. Borcherdt as zoo director.
Borcherdt designed the Bear Mountain exhibit, which opened in 1918. This structure is tall and long, and cost $50,000 to build ($ in dollars ). It was built of dyed and textured concrete forms cast from Dinosaur Mountain just outside Morrison, Colorado. Hidden moats replaced cage bars, and native plants and an artificial stream enhanced the natural look. The two main exhibits originally housed polar bears and grizzly bears.
The south tip of the exhibit was designed to resemble Mesa Verde National Park. It originally housed monkeys, but due to escape problems, California sea lions were housed there instead. Between 1941 and 1961 it housed a female polar bear named Velox, who became the mascot of the 31st Infantry Regiment in 1952. Velox died at the zoo in 1961 and a memorial stone for her is displayed at the zoo. Bear Mountain established Denver as one of the foremost American zoos, and the Saint Louis Zoo hired Borcherdt after seeing the exhibit.
Although other zoos in the region made extensive use of New Deal funds to upgrade their facilities, only one notable addition was made to Denver Zoo between 1918 and 1950. Monkey Island was built in 1937 using funds from the Works Progress Administration. Mayor Benjamin F. Stapleton funded the zoo very little, and it was in poorly maintained condition when Mayor J. Quigg Newton was elected in 1947. Newton hired DeBoer, the architect involved with the zoo's design forty years before, to plan a rebirth. Starting with the 1950 overhaul of Monkey Island, the zoo has steadily added to and improved its exhibits.
The Denver Zoological Foundation was created in 1950, the same year that the zoo acquired its first elephant, Cookie. A children's zoo was opened in 1951 (since replaced by Primate Panorama). A perimeter fence was built in 1957, defining the zoo as a separate area but still within City Park. Automobile traffic in the zoo was completely eliminated in 1959. Pachyderm Habitat was opened the same year, and Cookie was joined by a second elephant, Candy.
The zoo opened the Feline House in 1964, a Giraffe House in 1966, and an Animal Hospital in 1969. Bird World was opened in 1975, followed by the Mountain Sheep Habitat in 1979, Northern Shores for polar bears, Arctic foxes, North American river otters, and pinnipeds in 1987, and Wolf Pack Woods in 1988.
The Marine Mammal Protection Act of 1972 made it impossible to keep the polar bears and sea lions in the Bear Mountain enclosure. This, along with its deteriorating condition, led to a $250,000 renovation of the exhibit starting in 1987 ($ in dollars ). The exhibit reopened in 1989 with grizzly bears and Asiatic black bears occupying the northern two exhibits and coatis in the southern tip.
1990s-present
In 1993, the zoo opened the $11.5 million Tropical Discovery exhibit. Designed by the Denver architectural firm Anderson Mason Dale, this indoor tropical garden topped by glass pyramids is the public aquarium and herpetarium of Denver Zoo, and its opening doubled both the number of species and the number of animals at the zoo. Along with the animals, 90% of which had never been on display at the zoo, there are over 250 species of plants represented in the exhibit.
On November 6, 1994, twin polar bear cubs Klondike and Snow were born to a first-time mother named Ulu, who rejected the cubs. They were successfully raised by zoo staff and became a popular attraction. Their story is commemorated at Denver Zoo by a bronze sculpture located near the former polar bear (now grizzly bear) exhibit..
On February 24, 2007, a jaguar mauled zookeeper Ashlee Pfaff inside the animal's enclosure. The jaguar was shot and killed by the zoo's emergency response team while rescuing Pfaff, who later died of her injuries at a local hospital. This event occurred despite zoo policy prohibiting direct contact between keepers and big cats. An investigation by the zoo concluded the attack was the result of human error by Pfaff. The zoo has not had jaguars since 2010.
In 2009, Denver Zoo was the first zoo in the United States to achieve ISO 14001 certification. City Park rebuilt its greenhouses in 2009, providing the zoo with a dedicated greenhouse as part of this project.
That same year, Denver Zoo celebrated the birth of an endangered aye-aye, the first of the species to be conceived and born in a North American zoo. The zoo has continued to have a successful breeding program.
In 2012, the zoo opened the $50 million Toyota Elephant Passage. The exhibit was originally announced in 2006 as Asian Tropics. It was opened to the general public on June 1, 2012 as the largest bull elephant habitat in the world.
In 2015, following conservation work around Lake Titicaca in Peru, Denver Zoo welcomed 20 Lake Titicaca frogs from the Huachipa Zoo and later became the first zoo outside South America to breed the rare amphibians. Some have moved to other institutions in hopes of building a healthy captive population that can be released back into the lake.
The zoo added several interactive and immersive exhibits in the late 2010's and early 20's. These included The Edge in 2017, Harmony Hill in 2019 and Down Under in 2024.
In 2024, the zoo announced the acquisition of 570 acres in Weld County. This land, donated by the Lembke family, will be dubbed the Lembke Family Preserve. The new facility will not be open to the public but will increase space the zoo can use for breeding and reintroduction programs seven-fold. This is the first expansion outside Denver Zoo's 80-acre main campus in its history. Also in 2024, the zoo rebranded to reflect its ongoing focus on conservation and education and moving forward will be known as the Denver Zoo Conservation Alliance.
Exhibits Primate Panorama
Primate Panorama spreads over and primarily houses apes and other larger primates. Tree-dwelling apes and monkeys live in open-air wire mesh tents that soar four stories high and cover more than an acre of ground. Inside these tents, primates like Wolf's guenons, black-and-white colobus, red-crowned mangabeys, siamangs and black-handed spider monkeys can play and climb on twisting vines. Western lowland gorillas roam freely, climbing ropes and taking afternoon hammock naps in one of the largest gorilla habitats in the world. Sumatran orangutans have their own outdoor habitat where they can climb trees and swing in hammocks.
The Emerald Forest pavilion is situated near the entrance to Primate Panorama. It features a meandering trail through diorama replicas exhibiting many small primates amongst other rainforest animals. Animals housed here include the aye-aye, brown capuchin, cotton-top tamarin, golden lion tamarin, white-faced saki, Bali mynah and Prevost's squirrel. Connecting to the building is an island exhibit that rotates several lemur species, including ring-tailed lemurs and red-ruffed lemurs.
The nearby Shamba offers a view of a Central West African village and is home to red river hogs, mandrills, and cape porcupines. An aviary further down the trail showcases rhinoceros hornbills.
The Forest Aviary is a area richly landscaped and enclosed in a nearly invisible wire mesh. Visitors can walk around inside with the birds, which include unique and endangered species like (depending on the season) waldrapp ibises, Indian peafowl and a wide array of waterfowl.
Africa
Predator Ridge, completed in 2004 and the first exhibit most visitors encounter, is a large exhibit representing the African savanna. It has the ability to rotate multiple groups of Southern African lions and spotted hyenas, whose overlapping scents provide environmental enrichment. Other small African animals like dwarf crocodiles, African rock pythons, puff adders, and leopard tortoises are exhibited in and around the Pahali Ya Simba pavilion. A habitat for African penguins, featuring a 10,000 gallon pool with underwater viewing, was completed in 2021 and is located directly inside the front entrance.
African hoofed mammals are generally housed in the center of the zoo's main circular path. Species in the hoofed mammal yards include Grevy's zebras, reticulated giraffes, okapis, Somali wild asses, Cape buffalo and a variety of antelope species including eastern bongo, addax, lesser kudu, southern gerenuk, yellow-backed duiker and red-flanked duiker. Some of these yards are mixed-species exhibits and include bird species like Abyssinian ground hornbills, west African crowned cranes and ostriches. There are also yards for African wild dogs, Chacoan peccaries, llamas and a Vietnamese pot-bellied pig.
Asia