Axolotl: can't pick up in bucket if in flowing water or on land

In survival mode, I am completely unable to use a bucket on an axolotl that is on land or in flowing water.  I continue to hold an empty bucket on pressing "use", and get no bucket 'o axolotl.

 

I have difficulty with capturing an axolotl in a bucket when one is in water source blocks as well (hitbox may need some tweaking), but can do it successfully.