Not necessarily. This image, if exposed properly, could easily be done with one exposure and no need for HDR.
LennyP4868 wrote:
what you are trying to do is hard shooting at a sky in the background. your sensor is under exposing the bird and tree which is your subject. you want to show the detail on the tree and the bird, unless you going for a silhouette. To do this you have to over expose the picture and then stack it or HDR with one of your other pictures so the sky is not blown out. Hope this helps