What Birds are feeding in my feeder?

I live in Western Massachusetts (USA) and for a school project I needed to study a type of bird and watch its habits. I set out a bright blue plastic bowl and filled it with bird seed and some came. I cannot figure out what type it is because I am by no means a bird expert. It is a CHUBBY, SMALL bird with a LIGHT BREAST and a DARK BACK & HEAD and eats mostly the sunflower seeds in my bird seeds and leaves the others.I’ve seen a group of 14 at a time, and i looked in some books and I think it is an English/house sparrow. I asked some others and the other bird guesses were white breasted nuthatch, or some type of chickadee.Any information would be a help.

We have many sparrrows, chickadees, & nuthatches right now at the bird feeders. All the birds seem to prefer the sunflower seeds in the winter. Sometimes the book pictures are not as good as photographs. Some years, birds are lighter or darker than normal too. It is very difficult to determine the breed, even with experience. Another bird you may not have considered is the wren. We had one fly into our window last week and I brought it inside to revive it until he could fly again. He looked much like you described, very small, plump & the coloring was similar. They visit our feeders and hide under our car.
Here are pics of sparrows:

http://images.search.yahoo.com/search/images;_ylt=A0geu7X83VtJbe4And5XNyoA?ei=UTF-8&p=english%20house%20sparrow&fr2=tab-web&fr=ybr_sbc

Here are pics of chickadees:

http://images.search.yahoo.com/search/images?p=chickadee&sp=1&fr2=&y=Search&ei=UTF-8&fr=ybr_sbc&x=wrt&js=1&ni=21&ei=UTF-8&SpellState=n-1686781313_q-ECLbg.qNcd01UXZsLkhzsAAAAA@@

Here are nutcatches:

http://images.search.yahoo.com/search/images;_ylt=A0WTefNi3ltJQUYAHN.JzbkF?p=nuthatch&fr=ybr_sbc&ei=utf-8&x=wrt&y=Search

The wren pictures did not look like the wren I found (so I did not link them), but I still believe it was a wren. Hopefully, you will have a male or female Cardinal visit your feeder. They come here often before the other birds, sometimes as early as 6 A.M. That would be the best to study, and you would not be wrong about the breed. Good luck!

Cape White-eye, Zosterops pallidus, Glasogie

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