They'll probably eat more and feel less challenged as they can accsess the mouses easisly. Being in an envirment that challenges you is important, it is essential to self growth. Also it is unhealthu for the owls to eat to many mouses.
Since there is an increase in food (mice), there will be an increase in the number of owls. And this is because animals tend to move more to a stable and sufficient food source. The same way the same way the mice population increased when the weeds increased, owls will also increase in number.
I'm pretty sure it's primary growth. I might not have studied this type of biology yet, but secondary growth would definitely not be the answer.<span />
The root beer exerts a force on all sides of the ice cream. These forces are all equal and cancel each other out. Gravity pushes downward on the ice cream. The ice cream floats because the buoyant force is greater than the weight of the ice cream.