text: Well, it is the Blackbutt Reserve's picnic area located at the entrance of the reserve on Carnley avenue. The reserve has two entrances, one of them being located on Carnley avenue, which is the main one leading to the wildlife exhibits. So it is the "Carnley avenue entrance" of the reserve and it could be called the Carnley avenue picnic area. The fact is : this picnic area has no official name. It would make sense then to call it the Blackbutt reserve picnic area as it actually is the reserve's picnic area. Now there is no reason for it to be called the "Black Duck Picnic Area". 
  As a source, I was there today and saw it myself. You can also check out that link : http://www.newcastle.nsw.gov.au/Blackbutt-Reserve/Plan-your-visit/Location-Getting-Here/Map