How the feared black mamba can help us detect pollution levels

702's John Perlman is joined by study co-author Graham Alexander, Professor of Herpetology at the University of the Witwatersrand.

People who are terrified of black mambas have reason to be - the species is one of the most venomous snakes on the African continent and its bite is often fatal.

However, a study undertaken at the University of the Witwatersrand (Wits University) shows how this feared reptile can actually help humans when it comes to detecting pollution levels. (Read a summary here)

Researchers analysed scale clippings from live snakes that were removed from domestic, industrial and commercial properties in Durban by KZN snake expert Nick Evans.

The results mean that they can now use these clippings to accurately measure spatial patterns of environmental pollution levels, without harming the snakes.

Wits says it was the first study of its kind to examine accumulation of heavy metals like lead, arsenic, cadmium and mercury in an African snakespecies.

Co-author Prof.Graham Alexander summarises the reasons why black mambas are such a good indicator, including the fact that they're an apex predator feeding mainly on mammals, and occasionally birds.

"We know quite a lot about the dietary specialisation of black mambas. Also, reptiles don't move much - if we would looking at birds to measure heavy metals for example they fly around and you can't really pick up a spatial pattern because you don't know where the birds are experiencing the pollution.

Prof. Graham Alexander, School of Animal, Plant and Environmental Sciences - Wits University

"The mambas on the other hand live in fairly small areas. They are far up in the food web and they are actually building up levels of metals from their prey - if they're eating lots of rats and the rats have been exposed to this pollution, that accumulates in the body of the mamba.

Prof. Graham Alexander, School of Animal, Plant and Environmental Sciences - Wits University

The study’s findings highlight the value of having connected green spaces around our cities, as they help protect wildlife from harmful pollution linked to urban development.

Scroll up to the audio player to listen to the conversation