The Wood Sandpiper and Yellow Wagtail are both migratory. In fact, the Yellow Wagtail is one of the early winter visitors and is likely to begin its return migration soon since it is becoming pretty hot here.
Yellow Wagtail (or could be a Gray Wagtail)
It is easy to confuse between the Mynah and the Rosy Starling. The closeups show the difference - the starling has a rose coloured body. It is also migratory and spends winters in India.
Inputs: Usha Rajagopalan
Pics and bird ids: Nirupama Sriram