In the bird photography forums, many comments relating to head angle and catch light in the eye are given as part of a critique. Often "HA" is used in place of "head angle" and many times, new members have to ask what is "HA". Lots of attention is given to head angle in fact and some times this provokes a debate. Pity the forum member that posts an image of a bird facing AWAY from the camera! The image might be perfect in all other ways, but that one flaw is considered a deal breaker sometimes. Here is one of my images that was criticized for not having the bird turned more towards the camera. Everything else was fine, including exposure, clean background, good light, and feather detail.
Is head angle really a deal breaker? I don't believe it is always, because there are so many elements that can make an image very appealing. And not all of them have to be present all at once. After all, it comes down to what your eyes find appealing. But nevertheless, as a bird photographer, I value the "rules" of bird photography because most of the time, there are legitimate reasons for those rules. For me, an image of a bird is most appealing when I can see its eye(s) and when its head is turned toward the camera. This makes the image intimate and draws the viewer into it; encouraging them, if you will, to look at the bird and attempt to understand it. It doesn't matter to me if that is a rule or not, it simply works.
When I have the opportunity to capture a close up of a bird, I look for the following; head angle, catch light in the eye and no distractions such as shadows on the face or eye. That is what works for me. I rarely get a chance to capture a close-up portrait of a bird and most of this is done when I am on land (i,e., Anhinga Trail). On rare occasions (such as the albino yellow-crowned nightheron found on Biscayne Bay, as shown above), I can capture a close-up from the canoe. The image above is severely cropped, however!
Sometimes with a close up, I capture the bird looking straight into the camera. This can be really interesting, particularly with long beaked birds that have intense eyes. For these close ups, make sure you have a narrow enough aperture to get the beak into focus (unless you are going for a different look). I find f8 to f11 work well here. Background and foreground are also important considerations with close ups, unless the bird covers the entire frame (such as the cormorant above). In this regard, I would have liked the image of the royal tern below to be less busy, but the fact that it is a breaking wave on the ocean behind the bird's head makes it easier to overlook that flaw. Besides, the back wind raising its head feathers is really what makes this image work for me.
And of course we can't always get close ups, nor do we want to. Take the image of the brown pelican bathing in the water. The feathers are the best feature, but those eyes are pretty cool as well! If you can get that intense glare from a flying osprey, that's also very cool, as seen below. The osprey was not happy with me as I unknowingly came upon a nest that was only about 20 feet above ground on one of the Ten Thousand Islands in the Everglades.
Who can resist a duckling, such as this little musgovy duckling that wandered away from its mom a short distance. I love seeing the duck's eye clear from the grasses that surround it.
With birds, look for the eye, the subtle turn of the head, capture them in the best light and look for clear background so the bird remains the highlight on the image.