MKMapView returns wrong latitudeDelta and longitudeDelta in regionDidChangeAnimated

I am trying to talk to a web service for zoomed in or zoomed out locations on an embedded MKMapView. In the scope DidChangeAnimated method of my view controller (this is the method I use to catch any user gesture on the map), I call the following:

NSLog( @"latitude delta = %f", mapView.region.span.latitudeDelta );
NSLog( @"longitude delta = %f", mapView.region.span.longitudeDelta );

      

        
        
        
      

    

And the log entry reads:

latitude delta = 0.000435
longitude delta = 0.001930

      

        
        
        
      

    

However , if I request the lat / long dela manually after the regionDidChangeAnimated has been fired (i.e. the custom gesture is complete), I get this:

latitude delta = 0.008415
longitude delta = 0.011932

      

        
        
        
      

    

Why is there a difference? It doesn't matter if it is a zoom in or out gesture. There is always a difference. What's with that ???