A New Bird Feeder

So I just installed a new bird feeder in my back yard. The birds starting feeding from it about 15 minutes after I filled it with seed. Since then the feeding has progressed from 2-3 sparrows at at time, to a crazed frenzy of up to a dozen birds taking turns. I live only about 4 miles north of Manhattan in the suburbs but only a mile or so from a nature center where I often photograph all kinds of birds. So far mostly sparrows, one House Finch, a cardinal pair, one Gray Catbird, one Robin and 3 pesky squirrels. Things is the birds eat about the entire contents of the feeder in about 2 days, just under 1.4 quarts. Is this normal. The squirrels try to climb onto the feeder but so far it is squirrel-proof as advertised, so I don't think they are taking much of the seed.

Sounds pretty normal. I'm on Long Island about 40 miles from Manhattan, I've gotten a similar array of birds that you mentioned as well as Blue Jays, Blackbirds. In addition to squirrels I've also gotten chipmunks (good) and one rat (bad). When I got the rat I took it down since I was worried it was attracting the "wrong crowd". Mine isn't squirrel proof by design but the way I hung it I was positive they wouldn't get to it, but somehow they did.

IMAGE LINK: https://flic.kr/p/HTH1​od

Classy birds are the ones who take a seed and leave with it. Hogs are the ones who bring all their buddies and sit there over a cup of coffee and eat, eat eat.
Two days from full to empty, max.
A cake of suet doesn't last much longer when the blue jays are feeding young. I wish they wouldn't drop big chunks when trying to stuff their mouths full.
I have my feeder hung from the eave of my house and have a pulley system set up so I can lower it for filling. This keeps the squirrels and chipmunks from getting to it. If I forget to keep it as high as it can go, the bears take it down.