In July this year, the Iimbovane Outreach Project introduced 30 Life Science learners to the wonders of biodiversity, during two workshops held at the Centre for Invasion Biology.
C·I·B postdoctoral associate Dr. Natasha Mothapo used behavioural experiments to see if the African big-headed ant (Pheidole megacephala) can help to keep the spread of invasive Argentine ants (Linepithema humile) in check. Dr. Mothapo found that both species were very aggressive during fights. Their mortality rates were similar during one-on-one clashes, but Argentine ants suffered more deaths than did big-headed ants. When competing for food in the same environment, the African big-headed ant was able to keep Argentine ants from gaining access to the food.
Rainbow trout (Oncorhynchus mykiss) is among the most widely introduced fish in rivers of the Cape Floristic Region, and may pose a serious threat to endemic fish such as redfin minnows, members of the genus Pseudobarbus, which are a unique and vulnerable group of freshwater fishes. In the Cape Floristic Region alone, there are twelve species of redfin minnow, some of which live in only a single river or stretch of river. Nine Cape minnow species face a serious threat of extinction by introduced predatory fish, such as trout.
Cactus plants are a familiar sight in many gardens and nurseries throughout South Africa. However, native to North and South America, these plants are becoming serious invaders across South Africa. In 1976, 12 species were reported as invasive, now, already 34 species are considered problematic. They all share certain characteristics which include heavy fruiting, vegetative reproduction, spines, good dispersal mechanisms and a lack of natural enemies because of their taxonomic isolation. In response to this threat, in June 2012, a national Cactus Working Group (CWG) was called into action to develop a strategy for the control of invasive cacti.
Globally, Invasive Alien Species (IAS) are considered to be one of the major threats to native biodiversity. In Europe, there are about 12,000 alien species, 11% of which are invasive, causing environmental, economic and social damage. Given Global trends, it is reasonable to expect that the rate of biological invasions into Europe will increase in the coming years.