Zeeeeeeeeeebra

As I think I have mentioned before, zebra finches are pretty much the cheapest cage bird that can be bought in the UK. As a result, we sell an awful lot of them. What amuses me is that about 90% of the people that ask for them say the word 'zebra' the American way, i.e. zeeeeeebra (/ˈziːbɹə/). However, I would happily put money on those people saying it the English way (/ˈzɛbɹə/) when referring to the striped, horse-like creatures. I don't know why they feel it necessary to change the pronunciation when talking about the bird. Strange.