Attempting to capture a decisive moment in black and white

I don’t usually photograph in black and white because I see nature in colour and that is what I want to convey with my photography. However, for the photography course that I am enrolled in, we are trying to replicate the work of Henri Cartier-Bresson, in trying to capture the decisive moment. In his own words, what that means is that, "there is a creative fraction of a second when you are taking a picture. Your eye must see a composition or an expression that life itself offers you, and you must know with intuition when to click the camera. That is the moment the photographer is creative. Oop! The Moment! Once you miss it, it is gone forever." In walking around the Australian National University (ANU) I came to the area where some stairs lead down to Sullivans Creek from the precinct with many student services and facilities, including eateries, so it is a heavily transited area. There are often Gippsland Water Dragons (Intellagama lesueurii howitti) there, sunning their cold-blooded bodies on the convenient concrete stairs and walls. Concrete is really just a human-made rock, so it absorbs heat and makes a quick way for a lizard to warm its body. The dragon I was photographing had had enough of me, and ran across the top of a low wall to the adjacent stairs, climbing one step, only to pause at the top, poised on the edge. It appeared to be watching the students pass by the top of the stairs. Its eyesight probably registered the movement, but it seemed to forget my presence behind it. I was able to move slightly forward and take a few photographs, including the one above. I liked this photograph because it seemed to capture the decisive moment, when the dragon looked to the top of the stairs and a student was framed in the middle of the opening. The viewer is left to their own interpretation as to what the dragon may be considering. It is just fortunate that Canberra is a city where these water dragons have thrived with the changes to their environment and there is ample opportunity to photograph them.