Working with scientists at UCL and Stellenbosch University, I recently undertook a global assessment of the environmental impacts of alien birds, using the Environmental Impact Classification for Alien Taxa (EICAT). One of the important results of this assessment was that for approximately 70% of alien bird species, we have no data on their environmental impacts. These species are classified as Data Deficient (DD) under EICAT.

In order to understand more about why this is the case, we carried out a further study to identify factors that may influence whether we have impact data for alien birds. Whilst the results indicate that many species are likely to be DD because they have minor impacts that do not attract scientific research, they also suggest that some species may be DD for reasons that are unrelated to the severity of their impacts. For example, the availability of impact data was found to be strongly associated with the length of time a species had been resident as an alien, and the size of its alien range. This is important, because it suggests that some alien bird species (e.g. those introduced to new environments relatively recently, or those with restricted alien ranges) may have environmental impacts that are going unnoticed. Our study highlights the need to improve our impact prediction capabilities, in order to identify the types of DD species that are likely to have damaging impacts.

You can read the paper here.