We have focused primarily on natural light, which is usually the most practical light for bird photos. In some cases, however, using a flash can also be helpful. Normally it requires a strong flash used at a relatively close distance. Flash technique is a complex subject on its own, and one about which I know little, but here are a few cases where a flash can come in handy.
At night flash may be your only option. It may not give you a photo that you’ll treasure for its artistic merits, but you might want to document interesting nocturnal activity. It is probably worth mentioning that focusing in the dark can be tricky, and you may only have one shot before your subject flies away, so make it count!
During the day, at close range, a little bit of flash can be used to augment the natural light that is available. In this situation, the best result is usually a photo where it isn’t obvious that flash was used at all. This can be especially useful if your subject is backlit.
The reflection of the flash can highlight iridescence in a bird’s feathers. On St. Martin, this is particularly useful for our hummingbirds.