Arignar Anna Zoological Park (abbreviated AAZP), also known as the Vandalur Zoo, is a zoological garden located in Vandalur, Chennai, India, about 31 kilometres (19 mi) from the Chennai Central and 15 kilometres (9.3 mi) from Chennai Airport. Established in 1855, it is the second public zoo in India. It is affiliated with the Central Zoo Authority of India. Spread over an area of 602 hectares (1,490 acres), including a 92.45-hectare (228.4-acre) rescue and rehabilitation centre. The zoo houses 2,553 species of flora and fauna across 1,265 acres (512 ha). As of 2012 the park houses around 1,500 wild species, including 46 endangered species, in its 160 enclosures. As of 2010, there were about 47 species of mammals, 63 species of birds, 31 species of reptiles, 5 species of amphibians, 28 species of fishes, and 10 species of insects in the park. The park, with an objective to be a repository of the state's fauna, is credited with being the second wildlife sanctuary in Tamil Nadu after Mudumalai National Park.

Edward Balfour established the Madras Government Museum in 1851. He established a menagerie in the natural history section of the museum with a live leopard and tiger. As the number of visitors to the museum increased during the live exhibition, Balfour started a small zoological park in the museum premises in 1855. He persuaded then Nawab of the Carnatic to donate his entire animal collection to the museum. This became the Madras zoo and was one of the first zoos to be established in the country. It housed a collection of nearly 300 species of animals and birds by the next year. As the zoo expanded, it was shifted to People's Park in Park Town in 1863. In 1876, the zoo was spread over an area of 116 acres (47 ha) and was open to the public for free viewing. The zoo exhibits included a orangutan, two-horned rhinoceros, Malayan tapir, and black headed gull.

By the late 1970s, the zoo was surrounded by the city and had limited space for expansion. In 1973, the Government of Tamil Nadu constituted a team to plan for the relocation of the zoo to a new location within the next five years. With the handing over of a part of the land occupied by the zoo to the Indian Railways for the expansion of Chennai Central, the zoo was planned to be shifted to Guindy temporarily in 1978. In 1979, the Tamil Nadu Forest Department set aside 1,100 acres (450 ha) in the Vandalur Reserve Forest on the outskirts of the city to build a new premises for the zoo. The state government planned for the construction of a new zoo at a cost of ₹30 million (equivalent to ₹770 million or US$8.9 million in 2023). The land consisting of shrubs and eucalyptus trees was re-planted.

In 1980, the state government approved the layout for the zoo and issued additional order to expand the park to by 38.74 acres (15.68 ha). In 1981, designs were made for the animal enclosures, with the first enclosures completed in 1982. The first animals were moved to the new premises in the same year. The construction of footpaths, roads, staff quarters, and a veterinary hospital were completed in 1983. In 1984, water was diverted from the Palar to augment the water supply. The zoo was opened to public on 24 July 1985, and was named after earlier chief minister Annadurai. The park was expanded in 2000 by 92 ha (230 acres) to 510 ha (1,300 acres) with the addition of a rescue center and school.

The main objectives of the park are ex-situ conservation of endangered species, wildlife education, and research for wildlife conservation and management. The zoo aims to maintain a viable and healthy population of animals in naturalistic enclosures while facilitating public visitation.

The Tamil Nadu Zoo Authority was established with the chief minister as the chairperson in 2004 for the management of the zoo. The overall management of the zoo is headed by a director, who is assisted by deputy and assistant directors. The director is answerable to the governing board. The deputy director is responsible for infrastructure, animal breeding and exchange, training, and research. The assistant director oversees horticulture, electricity, water supply and public utilities, visitor facilities, and upkeep of animal enclosures. A team of five forest rangers are responsible for the maintenance and safety of various designated areas of the park. Three biologists are responsible for research and exchange, training, and record keeping. The zoo has a team of veterinarians, and animal keepers, apart from other administrative and support staff.

The zoological park is located along the eastern side of the Grand Southern Trunk Road at Vandalur in the south-western part of the Chennai Metropolitan Area, about 32 km (20 mi) from the city center. It is spread across 602 ha (1,490 acres) of rocky terrain with alluvial soil. The park has a small hillock towards the center which gently slopes in an east-west direction. The altitude ranges between 31 to 147 m (102 to 482 ft) with an average elevation of 50 m (160 ft). The park experiences a tropical climate with average temperatures on 26 °C (79 °F) and high humidity due to its location close to the coast. The summers are hot and humid with the highest temperatures recorded in May-June with an average maximum of 36.10 °C (96.98 °F). The temperatures are lowest in December with an average minimum of 21.68 °C (71.02 °F). The park receives most of its rainfall from the northeast monsoon during October-November. The average annual rainfall is about 140 cm (55 in).

The park is located within the Vandalur reserve forest. The original landscape consisted of sparse scrub forests consisting of Carissa, Gmelina, Eugenia, Acacia, and Intsia with intermittent dry evergreen vegetation. The vegetation included a few cashew and eucalyptus trees. Much of the original vegetation was preserved apart from necessary deforestation for the construction of various facilities and roads. The original vegetation was augmented by newly planted dry evergreen trees. About 138 plant species have been recored in the park. The park experiences a micro climate, different from the surrounding areas due to its dense vegetation. The Otteri lake is situated on the north-western side within the park and acts as a roosting ground for aquatic migratory birds. The lake attracts more than 10,000 migratory birds every year. The lake consists of planted Barringtonia trees, which serve as roost for the birds.

The main entrance of the park is located towards the south west along the Grand Southern Trunk Road. The entire campus is enclosed by a compound wall. Close to the entrance, there is a children's park on one side and lawns on the other side. The enclosure of water fowl is located close to the children's park next to the primate section, followed by the terrestrial birds. A circular pathway takes the visitors to the interior of the park around the hillock. The enclosures for the carnivores are situated on the top of the hill with the herbivore exhibits along the slopes. Lower down the road are two smaller loop sections with one consisting of the bear enclosures and the other accommodating the walk-through aviary. The bear section leads to the lion safari at the north east corner of the zoo.

Back on the main circular road, the reptile section is situated next to the road leading to the pre-historic animal park. It is followed by the enclosures for large mammals such as elephants, hippopotamus, and rhinoceros. The nocturnal animal enclosure is situated further down the road, followed by enclosures for ostrich, giraffe, zebra, and kangaroo. The circular road ends at the aquarium which leads the towards the exit. Recreational facilities for the visitors are spread across the park. The kitchen, animal quarantine and breeding facilities, veterinary hospital and stores are situated away from the visitor areas on the southern side of the park.

The animals are segregated and placed based on the taxonomic classification and geographic distribution except for specialized requirements such as water dwellers and nocturnal species. The enclosure dimensions and designs are customised basis the requirement of various species. The enclosures consist of various vegetation as favored by the species exhibited. Separate feeding areas and night shelters have been constructed along the enclosures. The animal viewing areas are open with concrete walls and moats separating them from the animal enclosures. The various animal enclosures also separated by adequate space and vegetation. Vegetation is also used to camouflage concrete structures for aesthetic appeal. As of 2022, the park housed 2,389 animals across 178 species.

Animal stock

Class	Species	Count
Mammalia	45	504
Birds	94	1,473
Reptiles	39	412
Total	178	2,389

The ungulate herbivore animals are enclosed in open paddocks with suitable tree species, equipped with separate feeding areas. Other mammals such as tiger, lion, bear, leopard, jaguar, fox, jackal, hyena, wild dog, and wild ass are housed in appropriate enclosures with open yards. The elephants are enclosed in large open space covering 25 ha (62 acres). Hippopotamus are housed in enclosures with open pools. Other large animals such as rhinoceros, giraffe, and zebra, are displayed in open enclosures separated by moats. Plans for night viewing of specific animals in the park was mooted in 2007. It was planned to be implemented by 2011 at a cost of ₹40.2 million (equivalent to ₹90 million or US$1.0 million in 2023). The zoo authorities completed the construction of appropriate enclosures for these animals and planted saplings around the night safari area. After multiple delays, the plan was scrapped by the state government in 2011.

As part of the park's development plan, safari parks were established for lion and deer inside the park. The lion safari is spread over an area of 20 ha (49 acres) of scrub forests. The entire safari area consists of 147 acres (59 ha), which encloses a deer park consisting of species such as sambar deer, and spotted deer. The park authorities planned to create a safari for animals such as gaur and bear. The proposed safari was to be created on the 18 ha (44 acres) of the hilly terrain within lion safari area. The plans were not implemented due to the low population of these species in the zoo.

The primate house houses various primates such as lion-tailed macaque, chimpanzee, savanna baboon, tufted capuchin, and red-handed tamarin. It consists of artificial perches, and swings to support the primates. The nocturnal animals section houses seven species including slender loris, porcupine, civet, and owls. It is modeled based on a cave ecosystem with glass enclosures, and was renovated in 2024 with better ventilation and light control. The pre-historic animal park consists of life size models of dinosaurs.

Water fowl such as black swan is enclosed in open water pools. The bird section is sub divided into two based on geography: Indian and exotic. The Indian section consists of galliformes such as peafowl, jungle fowl, spurfowl, partridge, and psittaciformes such as parakeet. Typical bird enclosures have about 1 m (3 ft 3 in) soil depth for vegetation with appropriate resting and nesting areas. The walk-through aviary was renovated and opened in 2010. It covers an area of 1.5 acres (0.61 ha) and was built at a cost of ₹2 million (equivalent to ₹4.5 million or US$52,000 in 2023). The enclosure is covered by 15 m (49 ft) tall large steel nets which give access to sunlight. It consists of lawns, fruit bearing trees, mud baths, and fountains. Trees with holes and heaps of stones have been provided for nesting. The aviary is amongst the biggest such facility in a zoo in the country. Aquatic birds such as ducks, cranes, storks, pelicans, ibis, herons, and hornbills are enclosed in large covered aviaries with flowing water and sparse vegetation cover. In 2024, the wetland birds enclosure was upgraded with a chain-link mesh enclosing a 18 m (59 ft) high dome, with wooden platforms for birds. The exotic enclosure consists of pheasants, cockatoos, macaws, and rosellas. Flightless birds such as emu, cassowary, and ostrich are housed in open enclosures.

The reptile house consists of reptiles such as tortoises, turtles, monitor lizards, iguanas, and separate facilities for crocodiles, and snakes. The serpentarium built at a cost of ₹0.4 million (US$4,600) in 2012 exhibits snakes in enclosures with fiber glass facades. The serpentarium exhibits various poisonous and non-poisonous snakes such as cobra, viper, sand boa, python, and anaconda. The crocodile enclosure houses various species in enclosures with pools. These include gharial, mugger crocodile, saltwater crocodile, and spectacled caiman. While various species have been donated by the Madras Crocodile Bank, others are bred at the center.

The park stands first in the country for establishing an amphibian captive facility, and it is the only zoo in the country to have amphibians on display. Locally available species such as Indian tree frog (Polypedates maculatus), common Indian toad (Bufo melanasticus), Indian bull frog (Rana tigirina), Indian cricket frog (Limnonectus limnocharis) and Indian pond frog (Euphlyctis cyanophlyctis) are exhibited at the Amphibian Centre. A water-recycling system has been introduced to keep the house clean, and plants have been planted inside each tank to add lushness.

The shark-modelled aquarium, with its entrance and exit points in the form of gills of the shark, is set amidst a pond and houses 31 species of fresh-water fishes. The pond surrounding the aquarium too has different varieties of fishes. There are 28 types, including angel fish, black ghost, electric yellow lab, glass fish, giant catfish, oscar fish, tiger barb, rykin gold fish, neon tetra, and zebra danio.

The butterfly house, constructed at a cost of ₹ 6 million, has more than 25 host plants and landscaped habitats, such as bushes, lianas, streams, waterfall and rock-gardens, that attract many species of butterflies such as the common Mormon, crimson rose, mottled emigrant, blue tiger, evening brown and lime butterfly. A network of ponds interconnected by streams maintains humidity in the area. The park covers an area of 5 acres. The butterfly garden with an insect museum at the entrance is set up by the Tamil Nadu Agricultural University (TNAU), Coimbatore. The insect museum has been planned with an exhibit area comprising insect exhibits representing the most common Indian species of all orders of insects both in the form of preserved specimens and in the form of photographs.

The Central Zoo Authority of India (CZA) has identified the park as coordinating zoo for the breeding programmes for endangered species as per the National Zoo Policy adopted by the Government of India in 1988, which states that the main objective of zoos will be to complement and strengthen national efforts in the conservation of the country's rich biodiversity and that the species which have no chance of survival in the wild would be bred under ex-situ conditions. The park has a high rate of success in captive breeding of lion-tailed macaques. In 2010, the zoo had 22 lion-tailed macaques, from a breeding pair that were brought to the zoo in 1983. The park is also successful in breeding other rare species in captivity, including ostrich, Asian palm civet, Indian gaur, wild dog, Asiatic lion, Nilgiri langur, sangai, hippo, Malabar giant squirrel, white tiger, Asiatic wolf, panther and bison. The zoo is among four in the country to have an ostrich. The park also undertakes cross-breeding as part of its conservation efforts. The park is also a participating zoo of the CZA for the captive breeding of rock python, Nilgiri langur, lion-tailed macaque, Asiatic lion, wild dog, Asiatic wolf, and gaur. The zoo also promotes exterior conservation—conservation of rare species in their natural habitat—whereby individuals born in the zoo are released in the wild after adequate training, as per the guidelines of the CZA.

The park has tree-lined paved paths for long treks inside the campus, enabling the visitors to walk 15 to 20 kilometres (9.3 to 12.4 mi) during a visit. Battery-operated vehicles with a range of up to 80 kilometres (50 mi) are available for rent. There are about 9 such vehicles in addition to the 4 battery-operated vans used for the lion safari and 4 diesel-run road rails used for going around the zoo, and the approval has been given in 2017 for two more vehicles. Each vehicle can carry 15 to 20 people, and each trip takes about an hour. A trial program of 20 rental bicycles for visitors, including 5 for children, was launched in 2008 as an eco-friendly option intended to reduce demand for the battery-operated cars. An e-bike facility was also inaugurated on 20 February 2010. By the beginning of 2018, plans were on to install 32 CCTV cameras in the zoo.

Refreshment outlets include a snack bar run by the Tamil Nadu Tourism Development Corporation (TTDC), an ice cream parlour and a soft drinks counter—all near the entrance. The park also maintains 16 toilets and nearly two dozen drinking fountains within the premises for the visitors. The zoo is open to public from 8:30 am to 5:30 pm except on Tuesdays, when the zoo carries out weekly maintenance work. All the animals, especially the big cats, are back in their cages after 5.00 pm and most tourists prefer to visit them before going on to the other exhibits. The zoo has a guest house located on Kelambakkam Road.

The zoo is fenced on all sides by means of the perimeter wall. The zoo security is mainly carried out by the forest subordinate staff of rangers, foresters and forest guards along with zoo security staff, who conduct regular patrolling of animal enclosures, stores and other buildings. Night security is carried out under the command of one range officer and other subordinates. The zoo has also employed private security personnel. From 1 December 2010, four persons from a private security service have been deployed along with forest rangers for night patrolling.

In July 2013, ambulance facility, equipped with an oxygen cylinder, pulse monitor, critical care monitor, stretcher, surgical tools, small cages, tranquilizing darts and emergency medicines, for animals inside the premises was inaugurated.

A research and training facility was set up in 2017 at an estimated cost of ₹71.3 million. It will conduct research on subjects such as endangered animals and their reproduction, besides suggesting ways and means to address man–animal conflicts.

In February 2011, the zoo began construction of a large new tiger cage at a cost of about ₹ 200,000, and the new cage will be linked to the existing one. The existing enclosure measures 26.64 feet in height, length and width. The new cage will be 13 metres (43 ft) tall at its highest point and 11 metres (36 ft) wide, enough for four adult tigers at a time. It will have separate entries for the animal keeper and the animals. Illuminated by solar-powered lights, it will have a sloping roof and good ventilation. There are 18 tigers in the zoo, 9 of which are white tigers.

For the first time since the shifting of the zoo from Park Town in 1979, the park underwent a major renovation in 2011, costing ₹ 32.5 million. The renovated entrance was inaugurated by the Chief Minister of Tamil Nadu, J. Jayalalithaa, on 19 June 2012. The new 6-m wide entrance features 250-m long, 2.7-m high brick-and-granite wall, with 43 mural relief sculptures representing different animals in the zoo and a 12-m fenced lawn. The main entrance tower is 10.5 m tall, with two adorning structures 8.5 m each on either side. Other additions include huge lawns covering nearly 300 m on both sides of the entrance, tiled floors, an interpretation centre (similar to the one at the Vedanthangal Bird Sanctuary) with LED displays at the entrance, additional ticket counters, and a souvenir shop selling memorabilia like T-shirts and artefacts showcasing the flora and fauna of the sub-continent. The new entrance also features 20 computerised ticket counters to handle huge crowds.

The zoo authorities are in the process of restoring and renovating the approach road to Otteri lake, located inside the zoo. Post-monsoon, the lake attracts many migratory birds, and the lake could act as an ideal spot to view birds at close quarters. Hence, a bird's viewpoint is being built to encourage bird watching.

During April 2010–March 2011, the zoo received nearly 1,810,846 visitors, as against 1,187,904 visitors in 2006–2007. In November 2010, the total revenue was ₹ 46.9 million, against ₹ 40.2 million during October 2009. There has been an increase of more than 200,000 visitors in 2010 compared to 2009, and the park had recorded a 21 percent increase in the number of visitors. The number of visitors raises to the peak on the Kaanum Pongal day, a day in the festival season of mid-January, when the visitor count goes up to 63,000 on a single day. About 57,000 visitors arrived on the Kannum Pongal day of 2009, resulting in revenue of ₹ 1.015 million. It was 56,555 in 2010 and 57,217 in 2011. The all-time record of 63,000 visitors a day was registered on the Kannum Pongal day of 2012, resulting in revenue of ₹ 1.1 million. Less footfall in 2015-16 due to floods in November and December 2015. Less footfall in 2016-17 due to closure of zoo for two months (12.12.2016 to 09.02.2017) after cyclone Vardah.

The number of visitors to the zoo is steadily growing by an estimated 10 to 15 percent every year. The visitor statistics and the revenue generated over the past years are listed below:

Year	Total number of visitors	Total revenue (in Indian rupees)
2002-2003	711,589	8,280,254.50
2003-2004	700,963	11,070,930.00
2004-2005	668,026	11,135,581.00
2005-2006	848,823	14,446,000.00
2006-2007	1,187,904	20,251,945.00
2007-2008	1,447,992	25,074,288.00
2008-2009	1,646,129	30,387,902.00
2009-2010	1,604,216	40,286,000.00
2010-2011	1,810,846	46,997,710.00
2011-2012	2,002,545	42,316,857.00
2012-2013	2,212,131	67,395,062.00
2013-2014	2,375,053	74,751,469.00
2014-2015	2,382,625	79,213,099.00
2015-2016	2,198,794	94,691,728.00
2016-2017	1,779,501	84,982,456.00
2017-2018	1,824,624	118,724,220.00
2018-2019	2,026,799	126,416,725.00

The zoo management has started to live stream all the animals and birds present in the zoo. To watch the live streaming, zoo management has created a separate website for the visitors who are not able to visit the zoological park.

The park has a zoo club, comprising college students, which was formed in 1997. The club helps keep the premises clean, and the members also conduct educational programmes and carry out patrols.

Following the death of a llama at the park after swallowing a plastic bag, plastic materials have been banned inside the park premises. Visitors are frisked at the entrance to restrict all plastic goods. The members of the zoo club are 98 percent successful in controlling the entry of plastic materials inside the park. The zoo also plans to introduce 'Friends of the Zoo' programme in line with the National Zoo Policy, prepared by the Union Ministry of Environment and Forests in 1998.

The park launched a zoo newsletter in 2000 to serve as a source of current news and developments in the park. Efforts are being made to publish the newsletter at regular intervals.

From 22 to 24 September 2000, the park conducted a workshop for keeping and breeding amphibians in captivity for the first time in India.

The park, along with the Chennai Snake Park, Madras Crocodile Bank and the Mysore Zoo, is slated to become a nodal point for captive breeding of endangered pythons in the country, especially the Indian rock python (Python molurus) and reticulated python (Python reticulatus).

In 2007, the zoo started to construct a separate breeding enclosure for the lion-tailed macaque, proposing to bring under Foreign Animal Exchange Programme. The enclosure was built at a cost of ₹ 1.6 million at a silent, remote place in the park to provide a natural habitat for the animals and to ensure breeding. The total enclosure measures about 3,000 sq m, including three rooms with about 250 sq ft. Three pairs of macaque could be kept in these rooms. The habitat is planted with fruit-bearing trees, including gooseberry and mangoes.

In July 2008, the world's first non-invasive birth control surgery on mugger crocodiles was performed in the park by the surgeons of the Madras Veterinary College to control breeding and inbreeding.

In September 2008, the park initiated Adopt An Animal, an animal adoption programme, which has seen a few takers so far in the state, with less than 20 sponsors, mostly individuals and companies, coming forward. The first adoption began with adopting a spotted deer, a peacock, two lovebirds and a parrot in June 2009. The park has received funds to a tune of ₹ 2.3 million from individuals and organisations for adopting animals between August 2010 and March 2011. The Zoo has also started online adoption of animals through the website Online Animal Adoption , where in anyone can adopt animals online from the Zoo starting Rs.100.

The park has developed an informative and illustrative guide in collaboration with the Centre for Environment Education (CEE), Ahmedabad, providing zoo ethics and comprehensive information including road map to the animal enclosures and visitor amenities.

In 2012, for the first time in the country, the park adopted 'social grouping' of animals in captivity, where members of same species would be kept together, to showcase how they interact in groups.

In March 2013, a blood transfusion performed on a 10-year-old hyena by a four-member team of doctors in the zoo, marking the first successful blood transfusion done for a wild species in an Indian zoo.

In April 2018, the zoo launched a mobile app to provide information on the zoo, online ticket booking, interactive map providing a virtual tour guide inside the premises, and so forth. Live streaming of animals on the Internet also began in the same period. The mobile App is available on Android and on Apple Store for download.

The Zoo School is the body under the Vandalur Zoo which conducts a lot of programs like the Zoo Ambassador Programme, Species Ambassador Programs etc and all the events can be registered online on the website

Vandalur Zoo is celebrating the wildlife week 2022 with a series of events where school students and general public can participate in a list of online and onsite activities at the zoo - List of Wildlife Week 2022 Events

Owing to its vastness and round-the-clock availability of animal medical care facilities, most of the rescued animals in the state, especially elephants, are brought to the park. With Chennai serving as a transit point for wildlife smugglers in Southeast Asian countries, the zoo also receives many recovered endangered species for rehabilitation. The three important captive management practices of the zoo that contributed to the longevity of animals include environment enrichment, psychological well-being and animal husbandry and veterinary care. There has been a considerable reduction in the mortality rate of animals in captivity at the park. Between April 2010 and March 2011, only 22 animals were reported dead, of which 9 died due to old age and the remaining owing to other health-related problems and infighting. Incidents of infighting, although rare, have been reported in the park.

With the guidance provided by the CZA, kraals—fencing of a portion of the moated enclosure—were created in the herbivore enclosures in 2003 in order to isolate and treat sick or wounded animal. Herbivores with physical problems are isolated in the facility to be checked by the vets. One of the corners of the enclosure is chosen mainly to keep visitors away from the treated animals. Kraals have been created in the enclosures of spotted deer, blackbuck, sambar, nilghai, barking deer, hog deer, brow-antlered deer, moufflon and bison. To make the animals get accustomed to the kraal, the feed is kept inside the premises. Apart from treating animals, the kraal also acts as a place for isolating animals in rut. For example, during mating season, males often fight with each other leading to problems for the veterinarians. To overcome this, the males are kept in kraals in isolation from other males. Kraals also help research scholars in observing and recording the movement and other activities of the animal, thus helping with studying their behavioural pattern.

The zoo also has a zoo kitchen, zoo hospital and quarantine facility. Every day, about 190 kg of non-perishable food items, 300 kg of perishable foods, 750 kg of beef and fish, 430 kg of cattle feed and 2,000 kg of fodder are being provided to the zoo inmates. A rat-breeding centre has been constructed near the store house to cater the needs of snakes. The fodder bank raised in the zoo premises fulfils the fodder requirement of the herbivores population in the park. The zoo orchard with trees such as mango, guava, and coconut supplies fruits for the park's daily requirement.

Rescue and rehabilitation centre

With the banning of training and exhibition of five species of animals, namely, lion, tiger, panther, bear and monkey enforced by the Government of India in 1998, a 92.45-hectare (228.4-acre) rescue and rehabilitation centre for animals was established next to the zoo with the assistance of the CZA in 2001. The area was acquired from the research wing of the Tamil Nadu Forest Department in continuity with the fodder bank of the zoo with an assistance of ₹ 14.598 million. The centre provides temporary and long-term care for confiscated and abandoned endangered animals, such as lions and tigers rescued from circuses, and is home to about 32 lions and 7 tigers. It has a capacity to house 40 lions and 20 tigers. It also has a reptile house and an aviary. The park is one of the five zoos in the country identified and funded by the CZA for the rehabilitation of circus animals. The rehabilitation centre is not open to the visitors.

Zoo veterinary hospital

The zoo veterinary hospital is responsible for disease prevention and health care management of the park's captive population. The hospital has a well-equipped operation theatre, in-patient ward, radiology unit, laboratory, clinical room, pathology room, quarantine facilities and convalescent yard fully functional to cater the needs of complete animal health care. It also includes a modern diagnostic laboratory with facility for periodic coprological examination, identification of causative organism, antibiotic sensitivity, pregnancy diagnosis, haematology, serology and urinalysis.

Water management

The zoo requires about 600,000 litres (160,000 US gal) of water per day for drinking, bathing animals, cleaning enclosures, and keeping the areas around them cool, much of which comes from the Tamil Nadu Water Supply and Drainage Board (TWAD). The remainder comes from 13 open wells, 5 borewells and the Otteri lake within the zoo premises. In 2011, the zoo started constructing rainwater harvesting systems, including small bunds and check dams, to store water during the monsoon that would otherwise be lost. Three troughs and a check dam have already been constructed in the safari to help store the natural runoff from the nearby hillock.

Power management

As of 2012, the zoo uses a lone 100-kV generator to meet the power shortage. The zoo has proposed to buy another 100-kV generator at a cost of ₹ 800,000.

In 2011, to save power and increase safety, solar powered lights were installed in 14 enclosures at the park at a cost of ₹ 200,000. The lion safari (old and new) and enclosures for white tigers, panthers, bears, hyenas, chimpanzee, a pair of lions, jackal, wild dog, owl, sloth bear, and brown bear are lit by solar power for about three hours every evening. Each system includes a solar panel and a 250-kv battery connected to a 33-volt bulb and can supply power for up to 8 hours.

Heat management

The soaring temperature in Chennai, especially during summer, demands extra care for residents of the zoo. Fortunately, the temperature inside the zoo campus is a couple of degrees lower than outside any time of the year, primarily due to the lush greenery. The park also maintains an exclusive summer management schedule. All animal enclosures have thatched roofs and fresh river sand spread on the floor to make it cooler for the animals. Water is sprinkled on the sand to provide extra cooling. Roofs of water birds' enclosures are covered with coconut leaves and wet gunny bags. Caves that are exposed directly to the sun are put under a shower twice a day. The enclosure for the king cobra has an air conditioner in order to provide an environment similar to its natural habitat as the species cannot withstand the summer heat. For birds, the topmost part of the cage is covered with jute bags, and water is sprinkled three times a day. Based on the temperature, cucumber, buttermilk, apple and banana are also served to herbivores. The zoo has also set up sprinklers to help animals beat the summer heat and is planning to set up about 20 more sprinklers at the deer safari.

In 2011, to increase the green cover, the forest department initiated to plant 25,000 saplings in the zoo.

In January 2002, when a panther from the Vandalur reserve forest entered into the zoo premises, the zoo was closed for over 45 days to facilitate search for the animal. After several attempts, the animal was finally trapped, and it was named after the zoo keeper, Arumugam, who first noticed the feline in the trap cage and alerted his superiors.

On 12 November 2007, a 13-ft long reticulated python was found in a ventilator inside the pygmy hippopotamus enclosure in the zoo. According to the zoo officials, the rescued python could have escaped from its enclosure, when it was young, 4 to 5 years ago. When the workers tried to take the reptile, it bit one of the animal keepers, but since it was a non-poisonous one, the animal keeper was not harmed fatally and was provided treatment for the injury. The reptile was feeding on small mammals, roaming freely inside the zoo, which helped it survive without any problem.

On the night of 10 July 2010, three sand boas (Eryx johnii), out of five in the enclosure, were reported stolen from the zoo.

On 2 August 2011, a 17-year-old male gaur named Mani was found gored to death in his enclosure, by a younger male named Vijay and aged 6, allegedly over fight for a mate. The zoo officials reported Mani was the oldest of the herd of gaur living in the zoo, and added that this is an unusual incident. On 20 August 2017, the same gaur Vijay also killed another 20-year-old male named Ratnam.

In January 2011, 50 birds died under dubious circumstances in the park within a month. Later, postmortem report found that they were poisoned.

In September 2011, a nine-feet-long Burmese python was reported missing from its enclosure at the serpentarium. The animal keeper forgot to close the channel connecting the snake's enclosure with an outlet outside with a piece of wood after the weekly clean-up, and the python had managed to crawl out. On 5 December 2011, after about 3 months, the animal was found in the bushes near the enclosure after swallowing a chicken kept near the enclosure as bait.

A three-year-old male white tiger succumbed to injuries suffered during a fight with its potential mate, a nine-year-old royal Bengal tigress, on 7 August 2013. The tigress, also severely injured following the fight. Deep wounds in the brain had resulted in the tiger's death. The incident came as a blow to officials at the Arignar Anna Zoological Park in Vandalur, who have been trying to prevent in-breeding among white tigers and strengthen the species gene through cross breeding. Christened by former Chief Minister M. Karunanidhi in September 2010, the deceased white tiger, Sembian, was paired with a nine-year-old royal Bengal tigress, Sathya, a few months ago. A litter of Dhole puppies were born in December 2021 and was available for viewing for public in an enclosure from June 2022 and this attracts a lot of visitors.

A 9-year-old lioness, named Neela and a 12-year-old lion, named Pathbanathan died due to COVID-19 in the month of June 2021. Out of 15 lions, 11 were tested positive for SARS‑CoV‑2. The zoo sent three set of samples to Centre for Cellular and Molecular Biology (CCMB), National Institute of High Security Animal Diseases (NIHSAD) and Indian Veterinary Research Institute (IVRI) for genome sequencing. On 6 June 2021, Tamil Nadu Chief Minister M. K. Stalin visited the zoo, to review the measures being taken by zoo authorities. The experts from Tamil Nadu Veterinary and Animal Sciences University (TANUVAS) were consulted to deal the outbreak.

In 2012, a wild-life research institute was proposed to be built inside the park at an expense of ₹ 342.4 million. This institute will be further developed in three years with the estimate totaling ₹ 743.7 million, with centres for ecological education and awareness, wildlife forensic research, and herbivores and carnivores field research.

In 2012, a turtle-shaped building was planned at an estimated cost of ₹ 400,000 to house various types of turtles in the park.

In February 2013, Chief Minister Jayalalithaa ordered to establish a wildlife research centre at the Park at a cost of ₹ 271.3 million. The centre will house eight research laboratories, including a nature education and awareness centre, wildlife forensic science research centre, and field research centres for herbivorous and carnivorous animals and will have two scientists, four junior researchers and two assistant veterinary doctors. The centre would cost the government an annual continuing expense of ₹ 2.699 million. The foundation stone for the research centre, which will be located opposite the main campus, was laid on 15 March 2013. The construction work is expected to be completed by mid-2014.

In July 2013, the public works department (PWD) was expected to begin work on a butterfly park in the zoo, an initiative sanctioned in 2001. The park is being constructed at a cost of ₹ 50 million. The caterpillar-shaped park with a landscaped habitat, nectar gardens, a walking bridge, pathways for visitors, breeding and rearing centres, and rock gardens will be built on 2.5 hectares, including the actual built-up area of 2,000 sq ft near the Otteri lake. The park has a network of ponds interconnected by streams to maintain humidity level. The caterpillar design was chosen because the 60-ft-long tube-like structure made of acrylic sheets, which will keep the inside of the building cool by absorbing less heat. The park will have more than 40 Indian species, including the common leopard, blue Mormon, yellow pansy, red Helen, and common Jezebel. Apart from local butterfly species, the park will host at least 80 exotic species of butterflies including the four-barred swordtail from Australia, the common savanna bush brown from South Africa, the Australian painted lady and the Danaid eggfly. The park will have a capacity to accommodate at least 100 persons at any given time and is expected to be ready by September 2013.

In 2013, a forest and wildlife museum was planned at the zoo, for which a budget of ₹ 2 million has been earmarked by the state forest ministry, including ₹ 500,000 for preparing display furniture, ₹ 200,000 for labelling, special light arrangements and fans, and ₹ 1.3 million for the collection and preparation of materials, a herbarium, xylarium, entomological collection, portraits, soil and rock collections and artefacts. The museum will be built near the exit gate on a 2,000 sq ft area. The museum is expected to be completed by the end of 2013–2014 financial year.

In March 2020, a safari world was planned at the zoo at a cost of ₹ 115 million, which would help visitors watch wild animals at close quarters.

The zoo also has a forest museum near the entrance, providing information about insects, plants, minerals, ores, and others.

• Flora and fauna of Chennai
• Guindy National Park
• Chennai Snake Park
• Madras Crocodile Bank
• Vedanthangal Bird Sanctuary
• Pulicat Lake Bird Sanctuary
• Mudumalai National Park
• Point Calimere Wildlife and Bird Sanctuary
• Periyar National Park
• Rajiv Gandhi National Park

• Kisling, Vernon (2022). Zoo and Aquarium History: Ancient Animal Collections to Conservation Centers. CRC Press. ISBN 978-1-00058-538-4.
• Narayan, Lakshmi; Reddy, KSSVP (2013). Master plan for Vandalur zoo (PDF). Central Zoo Authority (Report).

• "Central Zoo Authority". cza.nic.in. CZA. Retrieved 9 October 2011.