Dark-eyed juncos (Junco hyemalis) feed mostly on seeds and insects. In winter the junco’s diet consists mostly of weed and grass seeds, while in the summer insects are added. Juncos forage mostly while hopping and running on the ground. They will scratch with their feet in leaf litter or the snow. When at bird feeders, which they will visit, juncos tend to forage on the ground under the feeding tray.
A friend recently gave Leonard and me a niger (thistle) sock, which we hung on our back porch (near Lookout CA – Modoc County). As expected, the acrobatic lesser goldfinches (Spinus psaltria) swarmed over the sock devouring niger seed.
About a week ago the weather changed. Temperatures plummeted and the ground is covered with over a foot of drifting snow. Suddenly life became difficult for all our avian visitors. The juncos began eating the niger seeds that fell from the sock onto the porch. Then to our surprise juncos started to feed directly on the niger sock. At first the juncos were not adept at clinging to the fabric sock. There was much wing flapping and slipping off the sock. However, over a very short period of time, the juncos learned how to eat from the niger sock. They can now fly directly to the sock and get the seeds like pros.
We had no idea that juncos would or could utilize a freely-hanging seed sock. Perhaps they were forced to adapt since their usual food supply is currently hidden under deep snow. Leonard and I find this unusual feeding behavior fascinating. It may demonstrate that juncos are more adaptive than we believed.