River Terns of Bhadra & some questions!

In Bhadra, I was watching the river terns in the island. At first, it looked like a huge chaos, many birds flying here and there. But when observed for a while, we could notice a lot of organized activities among them - some go for fishing, some try to steal fish from others, some impress the mate with the food, some feed the young ones, some just circles the island, and so on. It was interesting to watch the activities.

I also observed river terns inspecting areas where cormorants are fishing, an easy way to find food.  

While watching the river terns' behavior, I was hooked with couple of questions.

I noticed that the adult river terns bring fish to the young ones, but does not feed them immediately. The young tern was shouting opening mouth wide open, but the adult observes carefully. In many instances I noticed, the adult take the fish back without feeding.
- How will the adult river tern identifies the young one?

 
I noticed the young river terns come closer to the water, tries to touch the water and with a lot of struggle, climbs back to the home.
- why do the young ones do this? As it is a water bird, wanted to feel (learn) the water?
- how do the young ones get water? will the adult river terns bring them in their feathers like some birds of dry land do? or will the young ones get water from its food (fish)?

 

 

I noticed a river tern, brings the fish, sat near the river bank and dipped the fish couple of times as if like washing the fish. It was strange to watch, but I couldn't guess a reason. In the image, the fish in the river tern's mouth was brought from somewhere else, but the bird sat on the bank and dipped the fish.
- what behavior is this?

 
Please do share your thoughts.