Waxbill

There are fast moving flocks of tiny waxbills (Estrilda astrild) here on Oahu.  M spotted some and I managed to get a picture (of her and the birds).

 
They are grass seed eaters native to east and southern Africa, but now they have spread to S. America, Europe and islands around the world.  Like the java sparrow they are in the Estrildid finch family, in fact I have seen Java sparrows joining and moving along in their flocks. 

Here is a java sparrow hanging out with the waxbills.

Often they weigh down the grass heads and feed on them next to the ground.

Also, they seem to spend a lot of time preening. 

sz