Tadpoles at the edge of the population are no more vulnerable than those at the centre.
The invasive species was likely brought to Australia unintentionally by ship. Now found in every state and territory, the wasps are decimating our ecosystems.
The predatory flatworm Obama nungara travelled in potted plants from Argentina to Europe, where it's distrupting soil ecosystems. Now, citizen-scientists are helping map their distribution.
Millions of dollars are being spent on trying to eradicate fire ants from Australia. But that might not be the only way to deal with the invasive pest.
Regulating species in South Africa is difficult. But identifying those creating the greatest tension, would shift focus on the most destructive species.
Many alien plants and animals have been introduced to Africa from other regions and spread from country to country, often having devastating effects.