The mass of Dark-eyed Juncos (Junco hyemalis) hopping about on the ground beneath the bird feeder could be called, more officially, a chitterring, a flutter, a crew, or a host. My personal term is ‘a jive’ as they bop and dance about. The dance, goes on along with Stellar Jays and Abert squirrels, underneath a freshly filled winter feeder. The Juncos prefer to hop on the ground sorting out their favorite seeds, which the Stellar Jays are generously throwing out of the feeder as they sort. The Juncos will fly straight up to the source as well. Mixing insects into their diets along with wild seeds, they can keep their rapid metabolisms revving through the coldest winters. The flocks will form up in the morning before sunrise for 6 or more hours of winter eating, and disperse near sunset to roost in the pine trees and other protected hiding spots.
Juncos are often called ‘Snowbirds’ as throughout most of the US Midwest and East, they arrive with the cold weather and depart in the spring to nesting grounds. Here in the Foothills, they tend to remain year-round. Worried about them on a below-zero day? No need to be. They pack on 30% more feathers during the winter months and, like most all birds, can ‘poof’ them out creating a nice pocket of warm air around themselves. A bird’s feet, those thin, boney legs actually do not get cold. Birds, and many other living creatures including humans, have an amazing circulatory mechanism called countercurrent circulation. In birds, where the leg meets the warm body, the blood goes out to the legs warm but comes back cold, and is then split into many smaller veins and arteries that inter-braid so that the warm blood circulating out, warms the cold blood coming back up to the heart. Brilliant stuff. For a diagram of this click here.
The Junco is one of the most common North American songbirds, with possibly over 600 million of them here. They have developed many variations in their ongoing evolution, up to 12 subspecies over the last 15 thousand years. Here in the Colorado Foothills, you will see both the Slate and Gray-headed (red-backed) juncos together making it look like they are 2 different bird species. According to ornithologist David Sibley, although their coloring is different, they “sound the same, act the same, and seem to recognize each other as the same species and interbreed wherever their ranges meet”. There is also an Oregon Junco that has yellow-orange sides, and a more distinct black head, but rarely seen here.
If you get to see a Junco’s coloring closer, (such as this one I rescued from our lanai when it got stuck and was hitting all the windows exhausting itself), as he rested in my gloved hand, you can see some of the variations in colors, making this a spectacular little bird. Adaptations in bird coloring provide both camouflage and distraction, in protecting from predators.
Do little birds have predators? You bet they do. Hawks, owls, cats, martens, chipmunks, red squirrels, and weasels all find the little birds and their eggs to be a tasty meal. As this bird likes to stay on the ground 65% of the time, and even has its nests in low shrubs or on the ground in grasses, it can be easy pickings for these stronger animals. Up to 80% of nests are raided by predators. But the Junco has a few tricks of its own like the camouflage, Junco dad defense, and also flying off with a distracting flash of their white tail. As banding records have shown, Juncos have been found in the wild up to 11 years old, they have proven themselves a savvy and lucky species also. Even so, their populations have dropped about 30% in the last 40 years due to habitat loss much more than predators.
So, a small bird plays a part in the whole environment as it eats then distributes seeds and is a food source for other creatures. Each member of the whole plays their role and considering that the Junco has been around for more than 15,000 years, they’ve got a job to do. Keep an eye out for them at your feeder and in your trees. You are likely seeing the same birds throughout the year. Winter companions are great to have.
Sources:
- What It’s Like to be a Bird by David Sibley, 2020, Knopf books, pgs154-155
- https://www.beyourownbirder.com/2018/12/03/weekly-bird-dark-eyed-junco
- https://animaldiversity.org/accounts/Junco_hyemalis/
- https://www.postindependent.com/news/local/birding-loving-dark-eyed-juncos/
Juncos