Non-Native Species in Britain

Press release from the British Trust for Ornithology

Pheasant. Photo by Mick DrydenA major new report on the establishment and spread of non-native species in Britain was published this week. Many of the Britain’s most abundant birds and mammals are included among nearly 2,000 non-native species currently established, and the number of new arrivals has increased dramatically over the last 50 years. The report has found that there has been a dramatic increase over time in the number of non-native species arriving in Britain. Of nearly 2,000 non-native species known to be established, over 600 species have arrived in the six decades since 1950, and 125 since 2000. This list is dominated by higher plants (1,377) with insects as the next most numerous group (278 species). Most of the established non-native species originate from continental Europe but the proportion of new species coming from Asia and North America is increasing.

As a highly visible and relatively well-monitored group, bird species comprise a significant proportion of the database but although well over 300 non-native species are regularly observed in the wild, only 15 are considered established (i.e. with self-sustaining breeding populations). Several species are among the recent arrivals in the UK (e.g. ring-necked parakeet) and work is continuing to eradicate others (e.g. ruddy duck).

Hottentot fig at La Corbiere. Photo by Henry GlynnAlthough the majority of non-native species are not considered invasive those that are can cause major ecological or socio-economic impacts if they establish themselves in the wider countryside. Invasive non-native species are considered to be one of the five major threats to biodiversity, estimated to cost the UK economy £1.7 billion every year. Overall about 15% of the species established in Britain are considered to have a negative impact. The research team looked at how to enhance the ability to detect and report non-native species, creating a new database of nearly 4,000 species within the GB Non-Native Species Information Portal (GB-NNSIP). Data on all of the species can be accessed through the portal’s website.

An integral part of the GB-NNSIP is a rapid-reporting system whereby particularly important new arrivals can be immediately notified to the relevant bodies. One such species, the Asian hornet, is not yet present in Great Britain but scientists believe could arrive soon, potentially having a serious impact on honey bees and other pollinators on which it preys. Anyone that suspects they have seen this species is encouraged to send in a photograph through the GB-NNSIP’s online recording website ‘Recording Invasive Species Counts’ which can also be used to report sightings of 19 other key species including water primrose, American bullfrog, carpet sea-squirt, tree of heaven, and American skunk-cabbage. 

In relation to birds, John Marchant of BTO said, “Climate change might easily make Britain more suitable for a wide range of non-native species, like sacred Ibis, currently thriving in southern Europe. Escapes and breeding of such species might be the beginnings of the next burgeoning new populations. To integrate non-native species recording more completely, we have ensured that all non-natives are fully recordable for BTO surveys.”

Details of the findings are contained within the report: Non-Native Species in Great Britain: establishment, detection and reporting to inform effective decision making. NERC Centre for Ecology & Hydrology, 110 pp. The report can be downloaded

Sacred ibis (in its native Africa). Photo by Mick DrydenNOTE. Although the report and the Species Information Portal do not include the Channel Islands both are very good guides to what is already happening and what is likely to happen in the future in the islands. Sacred ibis has already been recorded in Jersey, Guernsey and Alderney!