Photo 1: The 10 second shutter speed on the water fall looks really good, and with the rock itself, it adds so much to look at. The higher aperture is definitely a plus as the entire waterfall is the subject and showing all of it clearly is important
Photo 2: The sunset in the back is the perfect backdrop for for a silhouette as it provides just enough to look at for interest without drawing the eye away from the subject.
Photo 3: The fast shutter speed shows the eagle very well and the fog in the back being still adds to an effect of it lingering there. Although the eagle is the subject, the fact there is more there gives good context as to where it is and the kind of place you are at. The zoom is good because any farther out and the eagle would be hard to see, but closer and the mountain cannot fully be seen well.
Photo 4: The low aperture improves this image because it is not too low because the tree is also in focus, but low enough that the background is not. The rule of thirds is also well followed, as the bear is on the left third, the tree in the middle third, and is blank on the right third.
6 Animals of varying species, all looking at the camera.