I have the same problem - 3 males to 1 female. It's difficult to tell when they are stressed, but I separate my female when she's gravid and so that there is little competition for food and she's not pestered by the males. Problem is one of the males has figured out a way of getting over the partition in the tank! You can try lowering the water, as they are not meant to breed when water depth is low, but this doesn't work for my frisky lot.
Are you sure you only have 1 female? The newt at the bottom of the last picture looks female - fat, skinny front arms and not as flat a head as males have.........Does this one have nuptial pads?
Only other solution would be to get more females to take the pressure off...............which I am desperately trying to do!
