We’ve always filled our bird feeders with black oil sunflower seeds. Most of the time the seeds were in their shells. Watching chickadees one day, I wondered about the energy they used to pluck a seed from the feeder, then fly to a perch where they could hammer the shell open. Flight and hammering are energy-expensive efforts.
So, I bought sunflower parts and pieces. The seeds still needed hammering to get to bite size. Next, 50 pounds of roughly ground sunflower seeds, pieces small enough for chickadees to eat without leaving the feeder. And they do. From the feeder perches they grab and swallow most of the time.
The energy once spent on flight from feeder to perch, the energy used to hack seeds open and into bite-sized pieces became energy saved. That’s a good idea today. It will be a better idea come winter.
The other feeder birds — House Finches, goldfinches, nuthatches, blackbirds, grackles, and our three common woodpecker species — have no problem with smaller seed pieces. I imagine the smaller members of that list benefit as well. There is no shelling, no husking, those energy costs eliminated.
Husking — watch a goldfinch process a whole sunflower seed. Part of that process involves manipulation of the seed by the bird’s tongue to remove the husk. Ground seed has no husk.