Hi Vish,
One of the most important attributes you can bring to photograph is patience. Although politically incorrect, my mentor, a highly regarded New Zealand photographer used to promote the “one cigarette” rule. if you are just about to pack up the camera and leave a scene, take a few minutes out to wait and see what happens. Usually something will – it is all a game of patience.
Of course, being patient is one thing being prepared for the moment is another.
With this image, I feel the moment would have been better if we could see two things. One, the beak of this pelican, and two, some separation between the bird’s head and the the tip of its right wing. All of this comes down to two things, timing and your position in relation to the subject.
One point I would suggest, is that you reconsider how you use your ISO settings on the camera. I am guessing from your comments that you originally had the camera set up on a tripod, but became concerned about handholding the camera to get this photo.
One thing worth remembering is that you do not need to make all your photos at 100 ISO. In fact there is no harm at all in shooting at 400 ISO or even higher if the photos warrants it.
Shooting at 100 ISO will get you the best quality out of the sensor, but this becomes irrelevant if the shutter speed, or in this case the depth of field are not adequate enough for the photo. Most modern DSLR cameras are more than capable of making great images at 800 and even 1600 ISO. I even work at up to 3200 and 6400 ISO. Whatever it takes to get the moment.
In this particular instance I would have bumped the ISO up to 400, and this would have let me close the aperture a couple of stops to get more of the pelican, in particular its wings, in focus.
Hope this is a help!
Cheers,
Anthony