So,

I am walking to my house's top, climbing the stairs without difficulty. It night. As I reach the top however, I turn back and see that to my right a small duck is flying slowly. It is dawning as well.

As the duck comes close, I catch it with my left hand. It squeals and tries to get away, but it cannot.

The duck represents something that you want and that is out of reach, since you have been able to get to the roof of the house, but you still can't fly like the duck, and you can't catch the duck.

What does a duck mean to you?

Have you ever heard the phrase "If it walks like a duck, swims like a duck and sounds like a duck, it's probably a duck."?: If you have, this dream could be a play on this expression, telling you to pay attention to what should be obvious.

Thank you for your reply.

Mhm, interesting. I think you are correct because when I dream about birds, I am always trying to catch them -- though, why in this case it is a slow-moving duck as oppossed to the usual walking pigeon puzzles me a bit.

Something to consider I think is that the duck sets itself up to be caught: It flies slowly and tries to fly right in front of me, at which point I catch it.

A light brown duck... It evades me.

Which is precisely something I have problem with.

When I asked you what a duck means to you, I meant are there any particular qualities that you, personally associate with ducks that could be relevant.

One important quality of ducks is that they are very versatile and can handle themselves in different environments. They can swim, they can walk and they can fly. This dream could have to do with you having to adapt to different situations.

The fact that the duck sets itself up to be caught relates to the idea of paying attention to the obvious - catching (getting) what is right in front of you.

I understand, but simply I tend to associate all birds with flying.

True. The problem is that... I am not sure how to express it in English without sounding stupid.