Flowerpiercers are such amazing birds. They've evolved to pierce the base of flowers (thus their name) to drink nectar rather than nectaring like other birds. You can see the little hook on the end of their bill that they use for piercing.
In the wild, these birds are pretty difficult to photograph, as they flit from flower to flower, spending very little time in one area. Feeders make it much easier to get a view of these beautiful birds.