I don't post photos of nesting birds here until they are public knowledge, just in case it might some ill-intentioned person might stumble across the image and get ideas.
This breeding attempt was shown on The Secret Life of the Zoo tonight, so I can now post this image with a clear conscience. The female was walled in and the male fed her attentively. Unfortunately they did not rear a chick: The Secret Life showed that they produced a fertile egg but the embryo died after a few days. CCTV footage showed that the female moulted her primaries properly and then she broke out at the end of the normal incubation period. Disappointing but real progress for this pair.