Caatinga Antwren

These cute little birds band together in large groups for several reason--one is protection.
Even though they grow 4 or 5 inches long they weigh .04 percent. This boggles my mind!
A feather might weigh this much, well if it's a really big feather.
Wikipedia says their status is least concern, but other sites state they are vulnerable. Anyway that's my story and I'm sticking to it.