Including an ibex or an ibis would have avoided that unfortunate image of slaughter. The quagga is extinct in my dictionary, and a quail is an attractive bird (one that reminds me of dinner, sorry!) so one can only wonder at the omission. Maybe the author didn't think birds are animals.Clever dodge on the letter X. How old was the intended audience?
Griffin- I thought the same about the poor polar bears. What a horrific image. It's hard to countenance the zest with which people formerly killed animals for sport or pelts. I guess the target audience was preschoolers or thereabouts, although the rhymes are obviously not simple doggerel!