Grey Wethers and Black Bullocks

I couldn't resist calling these beasts bullocks, despite there being no absolute evidence to support this, and me being sufficiently unfamiliar with bovine appearance to say for certain that these are male animals.

Why is this?

Greenham Reflection: Spotted Bullock

Greenham Common is particularly wet at the moment. There are a number of ponds, pools and (possibly) lakes (I'm not sure how big a body of water has to be before it is called a lake) that are always there. There are also a lot of big puddles that occasionally dry up - if we have a hot, dry summer.