Birds - like humans - prefer wealthy areas

As female humans will attest, luxury is desirable.

A study of birdlife in South African cities has found that birds prefer wealthy areas to poorer ones.

But they will move out if things get too cramped. 

The study was conducted by a team of scientists from the universities of Turin in Italy, Cape Town (UCT) and the Witwatersrand (Wits). Their findings were published this week in the international journal of Global Change Biology.

Co-author on the study UCT associate professor Arjun Amar said in a statement: “This work is of particular importance because it is one of the few studies conducted in a developing country, and the only study of its kind in Africa, where urbanisation is predicted to occur at a faster rate than any other region on the planet.”

The researchers studied the occurrence of bird species in 22 urban areas across South Africa and found that the number of species present increased according to the income levels of residents.

The more affluent the neighbourhood, the more bird species are found there - provided there are still enough good habitats for the birds to spread their wings.

However, this was not true for highly urbanised areas where vegetation has all but disappeared.

The so-called 'luxury effect' also applies to relatively low-density urban areas in South Africa, where wealthy areas have a greater diversity of bird species than found in less wealthy areas.

This is probably due to greater investment in gardens, parks and other green spaces which are hot-spots of urban biodiversity in wealthier neighbourhoods, UCT said in a statement.

However, birds have no appetite for heavily built-up areas even when they have wealthy inhabitants.

It is the first time the ‘luxury effect’ in birds has been documented for an African country.

The study authors believe such findings could help shape future urban planning in the interests of both biodiversity and environmental justice, particularly in the rapidly urbanising developing world.

Lead author Professor Dan Chamberlain from the University of Turin said: “This study shows that rich, leafy suburbs have more bird species, and probably higher biodiversity in general, than poor areas of the city or areas that have too much asphalt and concrete. Understanding the factors which drive the ‘luxury effect’ will help us to design more biodiversity-friendly cities in the future, thus promoting environmental justice for all urban inhabitants.”