From the time we first pick up a camera, we are told to always photograph in the golden hours, but is that really the best time to photograph birds? Of course this is very subjective, but for me the answer is: it depends.
As it turns out there are actually very valid reasons for photographing anything in early morning and late afternoon. First, this type of lighting produced warmth in the image. Often you have a reddish-orange to yellow tint to your image. This, I think, gives the viewer the "warm fuzzies" if you will. Next, the light is lower to the horizon. This produces various effects depending on pollution in the atmosphere and so forth, but also gives us long shadows from the softer lower lighting.
I think the first and most important question you have to ask yourself is, "who is the viewer?" Who is going to, in the end, view your image. If, for example, the end customers or viewers are going to be scientific, then you certainly wouldn't want the yellow-orange cast to your image. This could interfere with the true color of the subject. In this case you would want a color temperature closer to white light. However, if you are looking to entertain the bird watching community with interesting lighting then you might want the softer side of the light and subject to shine through. In this case go for the more interesting orange and yellow light. Below is an image of a northern cardinal photographed in late evening light. Notice how the orange of the sun is interfering with the red color of the feathers. There is nothing inherently wrong with this approach and offers the user a much more artistic type of image to look at.
The next image demonstrates how to shoot with more natural color. If you are ever in doubt on color temperature, I recommend shooting under cloudy, and bright conditions. Below, I show a blue jay in his natural coloration. It was shot on a bright, overcast day.
In the end is is all a matter of personal preference, but do consider your target audience when making these decisions in the field. Also, you can adjust color temperature in post production, but I like to get as much right in camera as possible. Which type of image do you like and why?