What do raccoons, purple pitcher plants, signal crayfish and the yellow-legged hornet all have in common? No, this is not a joke - far from it. They are all on the GB invasive non-native species alert list. The introduction of invasive non-native species is one of the top causes of biodiversity loss worldwide. In this episode Sue and Alice meet up with UKCEH ecologist Professor Helen Roy to delve into the challenges posed by invasive non-native species and explore their environmental, economic, and social impacts.

They also catch up with Dr Olaf Booy, Technical Coordinator for the GB Non-native Species Secretariat, part of the Animal and Plant Health Agency, to find out about the work that goes on to identify, detect, monitor and eradicate invasive non-native species. Olaf also spoke about how events such Invasive Species Week (12-18 May) help to raise awareness of the issue and what you can do to help and get involved.
Hosts: Sue Nelson and Alice Hope
Producer: Rachael Buchanan
Counting the Earth is a Boffin Media Production for the UK Centre for Ecology & Hydrology.
Find out more:
Invasive Species Week – 12-18 May 2025
Non-native Species Secretariat
ID sheets for Invasive Non-native Species
Check, Clean, Dry
Be Plant Wise
Record a sighting of an invasive non-native species, especially an alert species