Birthday Greetings! and stores about ducks

Birthday Greetings to MGB! Wishing him well.

I remember a friend of mine told me a story about a duck attack they encountered. They were in a park in a city centre, walking around a pond. Suddenly, they heard this loud quacking and fluttering. They saw a couple of large ducks flying towards and then attacking a slightly smaller duck in the pond. They were biting and ravaging the smaller duck. My friends were puzzled by this behaviour, and subsequently heard ducks are known to rape female ducks. According to the Economist, Drakes are apparently notorious rapists (this document raises some other possible observations about research funding, but thats a different story). A blogger witnessed something similar and has a video showing it (I couldn't see video, due to restrictions on our proxy).

The above story has of course nothing to do with what I started thinking about, which is what would you do if you encountered a duck that had an injured leg beside a pond or a river? Would you ring someone? Would you get a Vet? Would you kill it "sympathetically"? or would you try and find out more about the duck and decide if it deserved to live or not and play God with it? What would you do if you found out the duck was a leader of a country and wanted lots of money, but got his leg broke because his mates were to fashion conscious?