Lighting and slanted glass causing unwanted reflections make for challenging photography in zoo enclosures.
I was at Twycross Zoo the other day the monkeys and apes make super subjects, but outdoors they are behind wire and can move very quickly, whilst indoors, the lighting and infra red heaters cause a yellow cast.
I took my series of primate shots by placing the lens quietly on the glass, then waiting for a response like the one here. I converted to mono to get rid of the yellow cast and a certain amount of noise caused by poor light, flash would be out of the question.
Pets and captive animals
ugly, gwynn56, lblythe