Walk-through bird aviary, Mumbai Zoo

Mumbai Zoo planned a walk-through aviary for exotic birds, where visitors enter the same space as the birds instead of looking in through a fence. The aviary covers 752 m² with an average height of 11 m, and Jakob Webnet forms both the roof and the side walls, on a steel structure designed with the architects, HKS Designer & Consultant. Acier took on design, engineering, supply and installation of the complete mesh enclosure.

An aviary for mixed species has one firm rule: the smallest bird sets the mesh size. A mesh that holds a large bird can still let a small one slip through or get caught. At the same time, visitors walking through need to see the birds and the sky, not a cage. The net also has to be taut, with no loose folds where a bird could be trapped. Roof and walls must meet without gaps, so the enclosure is closed at every edge.

The aviary uses Jakob Webnet in Ø1.5 mm stainless rope with a 25 mm mesh width. The 25 mm aperture keeps birds of every size safely inside. The fine Ø1.5 mm rope keeps the mesh almost invisible from within, so visitors look through it rather than at it.

In total, 1,672.29 m² of mesh was used, more than twice the covered area, because the walls are netted as well as the roof. Webnet is flexible and can be tensioned into curved shapes, so it follows the steel structure and its mesh-supporting pipes without creases. Stainless steel also needs little upkeep in Mumbai's humid, coastal climate, which matters for a structure that stands over live birds for many years. The installation took 6 to 10 weeks on site.

Visitors now walk among the birds under a mesh canopy that covers 752 m² at an average height of 11 m. The birds have height to fly, and the mesh barely registers against the sky. The aviary opened in 2020 in the same zoo as the leopard enclosure, and both use Jakob Webnet.