The silicone bands are designed to minimize the potential impact of carrying an external marking device .
Are currently in use on African penguins ( Spheniscus demersus ) at Bristol Zoo , UK and in the wild in South Africa .
The silicone bands are designed to minimize the potential impact of carrying an external marking device and are currently in use on African penguins ( Spheniscus demersus ) at Bristol Zoo , UK and in the wild in South Africa .