Spring training, continued

As spring advances, the flowers quickly change.  The crocuses have already been replaced by daffodils, hyacinths, forsythia, common daisies, and many more.  Each flower has a different shape, and it can take some experimentation before a bee learns to handle the flowers efficiently.  For example, this bumble bee made an awkward attempt to drink nectar upside down...

A bumble bee (Bombus sp., likely pascuorum) visits a glory of the snow (Chionodoxa sp.) flower.

... before switching to a more conventional approach at the next flower.

The bumble bee tries a different approach.

For another bumble bee, it was not the approach -- but the flower -- that posed a problem.  Corydalis flowers (pictured below) have their nectar at the end of a long spur.  To get the nectar, it is necessary to have a tongue long enough to reach deep into the spur.

A  bumble bee (Bombus sp., either lucorum or terrestris) trying to drink nectar from a Corydalis sp. flower.

This bumble bee's tongue was not long enough, yet it did not give up.  The opening of the flower was too far from the nectar, so the bee made a new opening closer to the end of the spur.

The bumble bee chewing a hole through the spur of the flower.

Although the bee gets the nectar this way, it fails to provide a benefit to the plant: either by pollinating the flower or by picking up pollen to carry to the next flower.  Therefore, this behavior is known as "nectar robbing".  Not all potential pollinators are capable of chewing through flowers.  However, once a flower has been robbed, all subsequent visitors have the option of using the shortcut to any nectar that remains and to any new nectar that is produced.

A hole in another flower is visible above the bumble bee's foot.