Framed in the lens of my binoculars is a tiny bird clinging to the reeds. For a moment, my entire attention is captured by the vivid flashes of yellow and white as the bird flits between the grasses. The surrounding backdrop of untidy skyscrapers disappears, and I am alone in a watery tapestry of bulrushes, fluttering dragonflies, and trilling birds. But the mellifluous calls of the Yellow-bellied Prinia (Prinia flaviventris) soon fade away, the pungent smell of sewage assails my nostrils, and I am bombarded with the sounds of traffic, the honking of horns, and the city once again impinges on my consciousness. I am in the Okhla bird sanctuary, situated in the heart of Delhi close to the Noida expressway, and I cannot help but marvel at the enormous biodiversity of this city that keeps throwing up new surprises every year-reports of a vagrant Smew or the Baikal teal making brief forays into this polluted city and its environs, even as the concrete jungle continues to gobble up surrounding peri-urban lands.