A zoo (short for zoological place; also called an animal park or menagerie) is a facility in which animals are kept within enclosures for public exhibition and often bred for conservation purposes.
The term zoological garden refers to zoology, the study of animals. The term is derived from the Greek ζώον, zoon, 'animal', and the suffix -λογία, -logia, 'study of'. The abbreviation zoo was first used of the London Zoological Gardens, which was opened for scientific study in 1828 and to the public in 1847. In the United States alone, zoos are visited by over 181 million people annually.
The London Zoo, which was opened in 1828, was initially known as the "Gardens and Menagerie of the Zoological Society of London", and it described itself as a menagerie or "zoological forest". The abbreviation "zoo" first appeared in print in the United Kingdom around 1847, when it was used for the Clifton Zoo, but it was not until some 20 years later that the shortened form became popular in the rhyming song "Walking in the Zoo" by music-hall artist Alfred Vance. The term "zoological park" was used for more expansive facilities in Halifax, Nova Scotia, Washington, D.C., and the Bronx in New York, which opened in 1847, 1891 and 1899 respectively.
Relatively new terms for zoos in the late 20th century are "conservation park" or "bio park". Adopting a new name is a strategy used by some zoo professionals to distance their institutions from the stereotypical and nowadays criticized zoo concept of the 19th century. The term "bio park" was first coined and developed by the National Zoo in Washington D.C. in the late 1980s. In 1993, the New York Zoological Society changed its name to the Wildlife Conservation Society and re branded the zoos under its jurisdiction as "wildlife conservation parks".
The predecessor of the zoological garden is the menagerie, which has a long history from the ancient world to modern times. The oldest known zoological collection was revealed during excavations at Hierakonpolis, Egypt in 2009, of a ca. 3500 BCE menagerie.