Those pics are classic.
Last time I went to a zoo, it was the lincoln park (?) zoo in Chicago...it's totally free and so fucking completely amazing...something similar happened, but it didn't have to do with animals fucking....a hippo was swimming around in a tank in front of a bunch of 10 year old kids, then proceeded to press it's ass against the window and take a huge yellow shit. You should have heard those kids screaming and laughing
If you're ever in Chicago, check out the zoo there...it's one of the few free ones left in the country.