Having the subject illuminated from behind can be a very nice effect. Out in the wild it can be tricky, compared to using backlighting in a studio setting where the photographer is controlling the light from light from all directions. The main benefit of backlighting is achieving a nice glow around the edge of the subject, and the main drawback is having most of the subject in the shade, sometimes making it difficult to see details.

Here are a few examples of backlighting. The cattle egret photo works the best, because the backlighting really brings out the details of the feathers around the head and creates a strong contrast with the dark background. There is also enough light to see the bird clearly.

The immature yellow-crowned night heron doesn’t gain as much from being backlit, but doesn’t really lose anything either.

The snowy egret with the small fish in its mouth loses quite a bit of detail and the backlighting doesn’t really make the image more appealing.

Overall, backlighting is fun to experiment and can achieve some very nice results, but it would take a better photographer than me to consistently use it to great effect.