Duck typing, must it be dynamic?

Question

Wikipedia used to say* about duck-typing:

In computer programming with object-oriented programming languages, duck typing is a style of dynamic

Answer 1

It's my understanding that structural typing is used by type inferencers and the like to determine type information (think Haskell or OCaml), while duck typing doesn't care about "types" per se, just that the thing can handle a specific method invocation/property access, etc. (think respond_to? in Ruby or capability checking in Javascript).