Chinese Geese
I’ve only ever seen Chinese Geese once before and that was here, at Crime Lake near Manchester.

Here’s my previous visit:
You can tell the sex of Chinese Geese from the size of their basal knob; the large protrusion on their forehead. I’ve pondered the function of the basal knob before:
Chinese Geese are kept primarily for their meat and eggs. Their other function is as guard dog, given how noisy they are when being disturbed. Quite why there’s a pair on a public lake is a mystery to me.

I wouldn’t want to argue with one. Would you?