Can APIs be Copyright?

As part of the Oracle lawsuit against Google, there is an interesting discussion going on about whether APIs can be copyright. Oracle argues that copyrighting an API is reasonable, claiming that APIs “contain many original and creative elements,” while Google notes that API design “is an art, not a science.” See Mike Masnick’s post on the topic here:

http://www.techdirt.com/articles/20110822/11242915616/side-show-oracle-google-patent-fight-are-apis-covered-copyright.shtml

My own point of view is that an API is a specification and does not exhibit any inherent behavior of itself; whereas an implementation that conforms to that specification has behavior and can involve intellectual property in terms of specific algorithms or implementation code. Moreover, an API is inherently public by definition – the point of creating an API is to allow other developers access to your implementation in a standardized way, and as such the API has to be public and open (such as via public header files in C++), versus a specific implementation that can be private and protected (such as the source files used to build a library file in C++).