I can vaguely remember someone telling me that if you touch a birds egg, its parents wont come back to them because

Question: I can vaguely remember someone telling me that if you touch a birds egg, its parents wont come back to them because your smell has been on them... is this true and if so, why?
- Keywords:
  bird,
  egg,
  fact or fiction,
  offspring,
  parent,
  smell,
  touch
Asked by biginside to Jo, Kevin, Louise, Valeria on 20 Jun 2012.
- Kevin Mahon answered on 20 Jun 2012:
  
  Hogwash! Something routinely told to us as a child, probably to stop us from stealing eggs and messing around in nests.
  
  Most birds have a limited sense of smell and can’t detect human scent! If they saw you doing it though you;d be in for a serious pecking!
- Joanna Cruden answered on 20 Jun 2012:
  
  While it is unlikely to stop the parent returning to the nest it is best to leave the eggs undisturbed

Question: I can vaguely remember someone telling me that if you touch a birds egg, its parents wont come back to them because your smell has been on them... is this true and if so, why?