The seagulls fly by pushing air down. That air would have to go somewhere, and in this case it would press DOWN onto the floor of the airplane. It would exert a downward force on the plane which is roughly equivalent to the force needed to hold the seagulls up in the air.
So, in short, yes.
It would weigh more, but it would be from all of the shite on the seats and floor.
My take on it is ,If the guls arent touching the body of the aircraft they support themselves, but if the air currants from their wings hit the air craft interiour they then apply force to the aircraft causing it to bear at least some of their weight.
Oh u r good!!
yes it would weigh 2000 pounds more. do you know why? even if they are flying
yes, its the weight contained inside, not necessarily the weight sitting on the floor