Sorry if this is wrong, as birds aren't my forte. Marwell had the attached sign located beside the aviary.
Weavers do seem to cause some confusion - and I'm not immune - especially as the male's plumage changes when they're breeding and according to region. I think one of the best guides is the colour of the eyes, although even that's not infallible. This is a typical example of a male Ploceus melanocephalus: Black-headed Weaver - The Internet Bird Collection ...and this Ploceus cucullatus: Village Weaver - The Internet Bird Collection