A new protocol for identifying and categorising the environmental impacts of alien species may help invasion biologists to
complete a global stocktake on the environmental impacts of all known alien species by 2020. This is one of the findings from a research
project where the Environmental Impact Classification for
Alien Taxa (EICAT) was used to assess the environmental impacts of alien birds.
The study, conducted by Thomas Evans and C·I·B associate Tim Blackburn from
Centre for Biodiversity and Environment Research (University College London),
together with C·I·B core team member Sabrina Kumschick, used the EICAT protocol on data from 415 alien bird species worldwide.
The EICAT protocol has been developed to help invasion biologists identify and categorise the magnitude and types of impacts
associated with alien species but to also allow the comparison of impacts of alien species across different regions and groups.
The study, which was published in
Diversity and Distributions, categorised alien birds by the severity and type of their environmental impacts. Most impacts were
categorised in the lower ranks as either Minimal Concern (MC) or Minor (MN), although 37 bird species had
moderate (MO) impacts or above, causing declines in the populations of native species.
The study further showed that alien birds primarily impact the environment through competition, predation, hybridisation and
frugivory (fruit-eating birds which caused the spread of alien plants). Impact data were found for only around 30% of alien bird species
worldwide, with the rest categorised as Data Deficient (DD).
The International Union for the Conservation of Nature (IUCN) may adopt
EICAT as their formal protocol for classifying the impacts of alien species. If this happens, EICAT assessments for all known alien species
worldwide should be completed and peer reviewed by 2020, in-line with the requirements stipulated under
Aichi Target 9 of the Convention on Biological Diversity (CBD) and
Target 5 of the EU 2020 Biodiversity Strategy.
The number of alien bird impacts assigned to each EICAT impact category. A further 296 species were Data
Deficient (DD). MC = Minimal Concern; MN = Minor; MO = Moderate;
MR = Major; MV = Massive (Evans et al., 2016).
“The study demonstrates that EICAT can be used to categorise and quantify the impacts of alien species for a complete
taxonomic class. It also indicates that there is much to learn about the impacts of aliens, as we have no information on the environmental
impacts of most species, even in a well-studied group like birds,” says Thomas Evans, lead author of the paper.
He adds that, “this is perhaps one of the key benefits of EICAT — by facilitating a global stocktake of the
impacts of alien taxa, EICAT directs attention not only to the most damaging alien species, but also to those species, taxa, locations or
impact mechanisms for which we do not have sufficient information, from which to make informed management decisions to mitigate the impacts
of alien taxa.”
Read the paper in Diversity and Distributions
For more information, contact Sabrina Kumschick at firstname.lastname@example.org