Black-vented Oriole: longer video clip

This is a slightly longer clip (2 min) showing the bird feeding on these lovely blossoms and demonstrating again it's excellent acrobatic skills. If these blossoms look like those in the other clips, they are--but it is the bird returning to drink the nectar again. In fact, it returned to a number of favorite/productive blossoms each time it returned to feed while I was there. Presumably these blossoms were providing more nectar each time as the bird appeared to be getting it. Does anyone know the mechanisms that this plant produces nectar? SeEtta