A zebra of a different vowel

What with my near-daily dose of BBC News on the radio, I thought I was pretty current on British-American pronunciation differences: furore with three syllables (and an extra letter), vitamin with a short I (VITT-a-min), con-TROV-er-sy with a different stress, and so on.

But zebra rhyming with Debra? Weird! And yet true, at least in parts of England. Bidialectal linguist Lynne Murphy, who blogs at Separated by a Common Language, explains why she now says zebra two different ways:

I pronounce it (to the extent that my American articulatory organs allow) in the British way when I say (BrE)* zebra crossing (a pedestrian [AmE]* crosswalk marked by stripes on the road -- as seen on the cover of the Beatles' Abbey Road). But when talking to my baby about toy animals, I revert to my mother tongue -- now my mothering tongue.

*BrE = British English, AmE=American English