Relocated wetlands beneath planned West Rail lines might be uninhabitable for birds, an environmental expert warned yesterday. The KCRC has identified two areas it says would be suitable for the relocation of 12 hectares of wetland, streams, fishponds and marshes which will be destroyed by the railway development. But the new wetland areas will sit underneath and around the rails, and Friends of the Earth assistant director Plato Yip Kwong-to said birds and other wildlife which bred, foraged and nested in the area would be scared off by the rumble of trains. Mr Yip, a member of the Advisory Committee on the Environment, said: 'It is ridiculous to say there will be no effect as trains will be passing every two to three minutes . . . it can have effects on the migration and breeding of the birds.' However, Kowloon-Canton Railway Corporation senior director James Blake said trains would run on a viaduct up to 25 metres high. 'At this height, effects on the ground will be minimal.' The viaducts and tracks would be lined with materials to absorb sound and vibrations, and trains would be fitted with side-skirts to minimise noise. The KCRC said the two areas suitable for the recreation of the wetlands were above the northern portal of Tai Lam Tunnel and just north of Kam Tin station.