Bird-watching has little of the popularity here that it does in Europe or the USA, where millions of people regularly settle down for a nice spot of spotting. They’re often caricatured as a dull breed bristling with notebooks and binoculars, and there’s some smoke to that fire, in the form of the tedious, trainspotter-like box-ticking some of them like to indulge in.

So what’s refreshing about Avistar, the biggest bird-watching fair in Latin America, is wandering around the feira and being embraced by the infectious enthusiasm of those who are, far from pedantic data-collectors, essentially, simply lovers of nature.

Brazil has an extraordinary avian biodiversity, approaching 2,000 species, which makes it a mecca for foreign bird-lovers. And it may come as a surprise to those in this urban jungle that, even here within São Paulo’s city limits, you can see over a quarter of them in the wild, from monkey-eating eagles to black-beaked toucans, and from ruby-throated hummingbirds to devil-eared owls.

This eighth annual ornithological extravaganza takes place, as ever, in Parque Villa-Lobos – a former rubbish tip turned park exemplar. Avistar’s gallery of the best avifauna photographs of the year is the result of a hotly disputed contest, with often remarkable results. At the fair, everything from books, bird-watching holidays and equipment will be on sale. Meanwhile, a series of workshops and talks (in Portuguese) running throughout the weekend, on everything from bird photography to conservation, should bring something of interest to the beginners and twitchers alike.