Thanks for pointing that out.
There wasn't a sign on the pen and I did look because it wasn't a native 'deer' that I'd seen before, so I just assumed it was some kind of deer!
So is the different coloured one at the back (darker colour), a male of the group or is it a deer that lives with them?
Finding reliable things to look for is actually pretty hard! The standard one would be that deer usually have branched antlers, rather than unbranched horns (as in antelope or cattle), but as there are both deer and antelope that have neither, and these are often restricted to females, and antlers in young animals or some species may not branch... that's not always too helpful! Antlers are also distinguished from horns in that they are shed every year and a new pair grown (which also leads to antlerless animals!)
In this particular case, it's worth noting that no deer have vertical stripes, so anything this general shape with stripes will be an antelope!
ok thanks for the tips, I've learnt something new, which is what this site is about I hope.
The stripes seems to be an easy give away for me to look for now that I know deers don't have them.
I did some reading about these antelopes and I've learnt that they like marshy ground, well apart from when it rains, they certainly dont have that in Birmingham!