We assess whether there have been changes in body size following successful establishment for seven passerine bird species introduced from the UK to New Zealand, using measures taken from individuals from contemporary UK and New Zealand populations, and from historical UK specimens collected around the time that individuals were translocated from the UK. 

There was no difference in fine scale density between seven invasive Alaskan and twelve native UK toadflax (L. vulgaris) populations in climatically matched areas.  However, some invasive populations were denser at medium spatial scales.  Alaskan ramets were shorter, resulting in lower fruit production, but had no seed predators and produced more viable seed per fruit.

Invasive parasitic species can be debilitating to their host populations, but the invasive status of parasites within an ecosystem is sometimes ambiguous. We investigated the invasive status and ecology of two trematodes of otters Lutra lutra recently identified in the UK. Both species cause biliary damage to their definitive host.

Spectroradiometry was used to distinguish and characterise the status of invasive non-native rhododendron in open and wooded habitats. The logistic regression model had a 93.5% success rate of distinguishing rhododendron from non-target species. Such data are critical to the development of strategic management programmes to eradicate rhododendron.

Hierarchical Bayesian models can be used to explore probabilistic relationships between a series of random variables and have demonstrated applications to pest species management.  Here I explore the use of Bayesian models in invasive species risk assessment and control using topical examples from Great Britain.  Bayesian models could provide a useful tool for prioritising invasive species for management.

The interactions between climate change and invasive species represent a serious threat to biodiversity. We estimate the current and future potential niches of fifteen high-risk invasive aquatic plant species, based on global climate data, and local environmental and land-use factors. Thus, we identify species most likely to benefit from climate change and areas at highest risk of multiple invasions.

The invasive alien harlequin ladybird, Harmonia axyridis, is a polymorphic species.  Melanic and non-melanic individuals can be found in Britain.  The UK Ladybird Survey receives occurrence records of H. axyridis including information on colour pattern form.  Here we examine the frequency of colour pattern forms, spatially and temporally, and the influence of the different forms on the invasion process.

The main aim of this project is to determine how climate and land use are affecting the distributions of non-native plants with different levels of establishment in Britain. Current distributions of established species are predicted best by climate variables, while casual and recently introduced species are associated with land use. Future distributions will be modelled using projected climate data.

The invasive rose-ringed parakeet has been established in the UK for over 40 years. We provide evidence that whilst the UK’s population has exploded over the last 10 years, the London population appears to be reaching its capacity. We examine the population dynamics of this exotic bird, and explore the implications of these findings for management of this globally expanding species.

We reviewed 87 articles to assess gaps in the research of alien plant species impacts. Most studies evaluated the impact of alien species on one native species in a single habitat or study site over few years. Alien impact studies should cover the whole life-cycle of natives over multiple years, and include several habitat types and study sites.

Grey squirrels were initially introduced with just ten squirrels to Woburn Abbey in 1890. They have subsequently spread (with additional introductions) throughout the UK and Ireland. We examine how the genetic diversity and genetic structure of this population has changed across space and time to understand the present population structure.

This population genetics study demonstrates that spread of the invasive American mink has not been spatially homogeneous and broad habitat differences throughout the invaded range influence expansion rate and direction.  Newly established populations share habitat types with source populations but are not panmictic with all populations at comparable latitudes. This has implications for targeting and prioritising management and control.