The terrestrial aviary was opened in 1992, but was closed within a few years due to maintenance issues. It was renovated and reopened in 2010 as the Bio Centre. This 1.5-acre (0.61 ha)[45] walk-through aviary cost about ? 2 million and is located on a slope behind the tiger house (12°52?56?N 80°05?29?E ? / ? 12.8823035°N 80.0913191°E ? / 12.8823035; 80.0913191 ). The aviary is the biggest such facility in a zoo in the country. The facility features fifteen-metre-tall fences to facilitate free flight of birds within the area. The aviary is home to about 245 birds of different species including Alexandrine parakeet, rose-ringed parakeet, blue rock pigeon, common myna, Indian koel, common babbler, white-browed bulbul, francolin, red-vented bulbul, red-whiskered bulbul, wagtail, pipit, orange-headed thrush, red-wattled lapwing, little brown dove and spotted dove.[46] The height of the aviary ranges from 5 metres (16 ft) at the top of the slope to 12 metres (39 ft) at the bottom, with the chain link 'roof' sloping downward from west to east. The aviary is surrounded by a 1-metre (3 ft 3 in) wall, and the four sides above this are covered with steel and blue-coloured nylon net in order to provide an open-sky effect. The ground is floored by tiled footpath lawned with Korean grass to maintain the humidity level. The moist deciduous habitat supports 22 tree and shrub species.[47][48][49] Fruit-bearing trees such as mango, pomegranate, guava, sapota (Sapodilla), jamoon, Singapore cherry and chillies have been planted for the benefit of fruit-eating birds. Heaps of dry leaves, dung, dry wood waste and rotten fruits have been provided for insect-eating birds. The zoo has also set up a mud bath facility for the birds. Palm trees with holes have been planted to facilitate natural breeding of parakeets, and heaps of stones have been provided for ground-nesting birds. The aviary also has fountains and water bodies for the birds.[46]
