PARK HISTORY The name “Bâtie` refers to a military construction built in 1318 at the far north end of the wood, but now nothing remains of it. In 1869 the Bois-de-la Bâtie estate was officially donated to the City of Geneva by Charles Louis and Auguste Emmanuel de Turrittini with the main condition of “maintaining and preserving Bois de la Bâtie as a place for public walks`. The legacy by the Duke of Brunswick to the City enabled the grounds to be laid out in the romantic style between 1871 and 1874. A pond, also used as an overflow for the reservoirs, was installed and now attracts interesting wild fauna. In 1982 the Animal Park was renovated and enlarged so that city dwellers could discover regional fauna and farmyard animals. Today endangered domestic animals are presented to the public in collaboration with the Pro Specie Rara foundation, INFLUENZA A H5N1 - Avian flu Avian flu is an epizootic that mainly affects wild or domestic birds, and more particularly aquatic birds. Rife in Eastern Asia since 2003, this highly pathogenic virus was detected in Europe in autumn 2005 in wild birds that are the carriers. In Switzerland wild birds were positively tested in April 2006 without, however, any contamination of domestic birds or humans. But the risk exists and is greater among people in frequent contact with poultry. One of the measures taken to prevent the introduction and spread of avian flu is quarantine for breeding birds from mid-October to end April or during the periods of migration. PROJECT FEATURES The project for a new aviary at Bois-de-la Bâtie was the opportunity to examine a specific programme: a provisional habitat for anatidae (family of aquatic birds). The architects explored different avenues taking into account, for instance, sensitive integration into the site and the creation of a specific habitat for the bipeds occupying the aviaries. The contracting authority's request: to build two aviaries, one for anatidae in quarantine and another for exotic birds. As the project advanced this second aviary was transformed into an aviary for rare native species. A particularity of the project order was the freedom (rare nowadays) to choose where the building would be installed. The architects chose to place it in the centre of an artificial island that must be crossed to reach Parc de la Bâtie and to transform it into a “bird island` through which strollers would pass on their way to the park. With the aim of prompting rethinking of the park as a whole, the decision was taken to create a single roof joining the two aviaries making it the new entrance to the park. The aviary was integrated into its host environment by two main elements: a roof shape, inspired by the site’s morphology, interacting with the crowns of surrounding trees and a tree-like structure supporting the reinforced concrete slab. The roof shape creates the general volume of the aviaries that are enclosed by supple metal netting encompassing the organic shapes of the concrete area. Each of the sixteen pillars constituting the structure is independently designed, its form inspired by the trees surrounding the aviary. The tricky, complex static calculation was carried out using an experimental method that required very close collaboration between the architects and the civil engineers. Based on a method that was first developed by Antoni Gaudi for the static calculation of Sagrada Familia in Barcelona and then perfected by the German engineer Frei Otto, the perfect balance of the pillars, all with a diameter of 15 cm, was calculated by the scientific transposition of studies of physical models. The result was a unique structural design stemming from suspended models. The varied colours of the pillars also mirror the site. A photo shot of the landscape was pixelled, then 6 “synthetic` colours were chosen and worked for dispersal on the sixteen pillars. The aim was for these colours to create a dialogue with the tones of their immediate surroundings. The metal netting enveloping the aviary was designed to define a supple, gentle volume, suggesting transparencies and plays on light.