Their sheer size makes them extraordinarily efficient pollinators.
However they are not the most efficient pollinators of some flowers.
Wasps are also responsible for the pollination of several plants species, being important pollen vectors and, in some cases, efficient pollinators even more than bees.
Additionally, Mexican free-tailed bats are also efficient pollinators.
Bats are more efficient pollinators of the flowers than are the insects that also visit.
As a solitary but gregarious bee species, it does not build colonies or store honey, but is a very efficient pollinator of alfalfa flowers.
The angle of the nectar spur is very important in the pollination of the flower and in determining the most efficient pollinator.
As a solitary bee species, it does not build colonies or store honey, but is a very efficient pollinator of alfalfa, carrots and some other vegetables.
But honeybees aren't particularly efficient pollinators.
Bees gathering nectar may accomplish pollination, but bees that are deliberately gathering pollen are more efficient pollinators.