I am a bird commonly found in cities, and build my nests on cactus plants. Who am I?

Q. I am a bird. My species' population is on the rise unlike many other species of birds. My colour is generally pinkish-white. I stand around 1.5 metres (5 feet) tall in height and weighs between 2 – 4 kilograms. I am a migratory bird. My species come in thousands to build nest mounds from the salty mud in the Rann of Kachchh. Who am I?

Q. Doves are white coloured birds that make nests mostly on mehandi hedges and cactus plants.

Q. I am a desert tree found in Australia. I store water in my trunk. Who am I?

Q. I am found in aquatic habitat, my body is covered with scales and my ears are hidden. Who am I?

Q. I am a complex sugar found in plants responsible for hardening of sclerenchyma. Who am I?