Name the most intelligent family of birds with respect to reasoning power?

Those are generally reckoned to be the corvids. Crows, Jays, Magpies, Choughs, Ravens etc. We know that crows can count (they can recognise a box with food in it by the number of spots on the top, regardless of size or disposition of the spots).

We know, by observation, that they can work out how to use simple tools.

They have been observed dropping pebbles in water jars to raise the level of water to a drinkable level.

Not such bird brains after all.

Big bird ... From Sesame Street because he taught me sign language. Yes I've been drinking tonight because I had a work social things so none of my answers will be logical at all expect to me  ... But that's not really any different from when I'm sober .. So it's fine.  Big bird.

Ray answered it the best. The magpies that live out the front of my property take on the foxes and squirrels.

I was at our local park, and I had bought a Cherry Bakewell and a chocolate muffin at the café and two cups of tea. My partner had walked up to the car park to check on the car. In the meantime I'd sat down on a bench, and realised my bottom was getting wet, I'd sat in a puddle. I put our cakes under my hat and carefully negotiated the route to the toilets walking backwards to save the embarrassment of people thinking I'd wet myself.  I stood with my bottom under the hand dryer whilst watching our table. Suddenly a crow flew down landed on our table, lifted up my hat and picked up the Cherry Bakewell in its wrapping and flew off with it.  I couldn't believe it, it was a giant sized cake, certainly not light, the cheek of it, I just stood there with my mouth open. I went back to the table. My partner returned and I said " A crow has just flown off with your Cherry Bakewell." He said "Yeah right" and started laughing. I said "No, really a crow just flew off with your cake."

Suddenly the crow flew back down with the cake, struggling to open the wrapper, and thankfully redeemed me from looking like a greedy bugger. Then it was my partner's turn to stand with his mouth agape.

I love to watch crows .... They are so smart!

I have to agree with ray ,

But I have seen on tv , a female duck

At a park , take the bread crumbs and walk to a pond , drop the bread crumbs in shallow water to attract tiny minnows , then eat the minnows ...

That's pretty smart ..

Man has built huge airplanes. But how much more versatile are the birds, including the hummingbird, which weighs less than an ounce [30 gm]! A Boeing 747 must carry 47,000 gallons [180,000 L.] of fuel, be operated by a trained crew, and employ complex navigation systems to make a transoceanic crossing. Yet, a tiny hummingbird relies on one thirtieth of an ounce [1 gm] of fatty fuel to carry it all the way from North America, across the Gulf of Mexico, and into South America. No heavy load of fuel, no training in navigation, no complicated charts or computers! This tiny bird is instinctively wise, being programmed thus by its Creator, Jehovah God.