Some of my worst zoo experiences involve looking forward to seeing a particular animal or exhibit in a zoo and the animal doesn't emerge or the exhibit is closed. While I saw a platypus at Taronga, the Nocturnal House was closed and I never managed to see some of the unusual Australian mammals I'd wanted to see. Similarly, despite frequent movements to and from the Nocturnal Lemur House in Paris, I never managed to see the hairy-eared dwarf lemur.
One of the biggest anti-climaxes was at a snake farm in Bangkok. the label said 'flying lemur' and the two Thai guides wondered why I kept returning to the enclosure. Eventually, the animal emerged. It was very attractive, but it was a giant flying squirrel, not a flying lemur at all.
It is also disappointing when I've been to a zoo and other people have visited the same zoo and seen an unusual animal behind the scenes. These include people who were shown the marbled cat and a species of leaf monkey at Howletts Zoo.
I suppose the biggest disappointment was the fact that I was returned to a hotel in Antanarivo in Madagascar, while some people I'd met in Berenty went to the Tsimbazaza Zoo I'd visited a few days before. The next time I met them, I was told that they'd been shown a monkey that had been captured in the wild in Madagascar. This could have been a macaque introduced to Mauritius, but as I didn't see the animal, I can't say if it was a lemur or a monkey. If it were the latter, how did it get to Madagascar?