Invasions by alien species may cause a decline in populations of vulnerable protected species through interference and resource competition. During the last decade, four invasive goby species of Ponto-Caspian origin have displayed rapid dispersal in The Netherlands. High densities of these species have been recorded in large rivers and hydrologically connected water bodies such as canals and fl...

The magnitude of impacts some alien species cause to native environments makes them targets for regulation and management. However, which species to target is not always clear, and comparisons of a wide variety of impacts are necessary. Impact scoring systems can aid management prioritization of alien species. For such tools to be objective, they need to be robust to assessor bias. Here, we ass...

Increasing globalization and human mobility have facilitated the intentional and unintentional introduction of species beyond their natural geographic ranges. Such alien species are considered to be a main driver of global biodiversity loss with substantial environmental and economic impacts on invaded communities. While the potential economic cost for almost 90% of the alien species found in E...

Introduction This account provides a brief overview of alien plant invasions in South Africa, with special emphasis on what is known about their consequences, including those affecting the delivery of ecosystem goods and services. We draw on published and unpublished sources, and highlight some important research challenges in invasion ecology that need to be met if we are to address critical g...

Studies of pairwise interactions have shown that an alien plant can affect the pollination of a native plant, this effect being mediated by shared pollinators. Here we use a manipulative field experiment, to investigate the impact of the alien plant Impatiens glandulifera on an entire community of coflowering native plants. Visitation and pollen transport networks were constructed to compare re...

Chalcid wasps (Hymenoptera: Chalcidoidea) are probably the most effective and abundant parasitoids of the horse chestnut leaf miner (Cameraria ohridella), an alien pest in Europe that lacks specialized enemies. We studied how the species richness and abundance of chalcids are influenced by altitude, direction of an alien spread and host abundance of C. ohridella. We quantified the numbers and s...

Alien reptiles and amphibians have been relatively little studied compared to other classes of vertebrates. This appears largely due to the fact that most species are cryptic and difficult to notice and because they do not often directly impact humans or their domesticated animals. I compiled a global database of alien reptile and amphibian introductions (with an “introduction” being the human ...

Aim More than 90 marine fish species in the Mediterranean have been determined to be alien species of Red Sea origin to date and therefore it is important to prioritize research into cataloguing their distribution and impacts. The aims of this study were to establish a barcode library for alien Mediterranean fishes of probable Red Sea origin and to initiate analyses of their invasion dynamics.