I think they are trying to sell tickets in "time-slots", Meriad, and discourage folk from just turning up on the day. I can accept that it is the sort of attraction which would get crowded, but it's almost like you have to make an appointment to go, these days. As for heavily discounting tickets on the internet, well, it's just the same as it is the railways, really.
They got penguins? lol
I got Penguins in the confectionery aisle of my local Co-op, Vic ....