Range expansion of an invasive species through a heterogeneous landscape – the case of American mink in Scotland

Abstract

Aim The impact of invasive species is one of the main causes of biodiversity loss world-wide, and as a result, there is much interest in understanding the pattern and rate of expansion of species outside their native range. We aimed to characterize the range expansion of the American mink (Neovison vison) invading from multiple introduction points through a varied landscape bounded by coastline to better understand and manage its spread.Location Scotland, UK.Method We collated and used records of mink presence to calculate the historical range and rate of range expansion at successive time intervals. We used a presence-only model to predict habitat suitability and a newly developed individual-based modelling platform, RangeShifter, to simulate range expansion.Results Records showed that mink were distributed throughout Scotland, except in the far north. We found that the rate of spread varied both spatially and temporally and was related to landscape heterogeneity. Habitat suitable for mink in west Scotland is restricted to the coast.Main conclusions We concluded that temporal and spatial variation in range expansion is attributable to heterogeneity within the landscape and also demonstrated that the potential for long-distance dispersal does not necessarily facilitate range expansion when availability of suitable habitat occurs in narrow strips and/or is fragmented. We have highlighted methodological gaps in calculating rates of expansion in invasive species but have demonstrated alternative methods that successfully utilize presence-only data. Our study reaffirms that invasive species will colonize less favourable habitats and highlights the need to remain vigilant of their potential for expansion even when distribution appears to be static for a time.

Predicting and understanding spatio‐temporal dynamics of species recovery: implications for Asian crested ibisNipponia nipponconservation in China

“…Ignoring potential long-distance dispersal events in range dynamic modelling may lead to inaccurate predictions, but caution must also be exercised in drawing firm conclusions from a single-sex model in which genetics and inbreeding depression are not represented. Moreover, we also found substantial variation in the strength of effect of this parameter on demographic features between time periods with much weaker effects during the first few decades, which may indicate that long-distance dispersers will not substantially contribute to the establishment of satellite populations beyond the current range when habitat availability is limited and/or fragmented, as shown by Fraser et al (2015). Using static spatial predictions from SDMs in spatially explicit simulations of non-equilibrium population dynamics, hybrid modelling substantially improves our ability to predict species range expansion and understand processes affecting the dynamics (Franklin, 2010).…”

“…Our study demonstrates that a hybrid model for species range expansion, which has been increasingly used in the study of biological invasions (Gallien et al, 2010;Fraser et al, 2015), can assist in conservation management of threatened and endangered, but recovering wildlife populations, as they recolonize their former range. Range expansion modelling provides guidance to allocate conservation resources.…”

“…Hybrid models have been used to explore the impacts of environmental change on species since the development of RAMAS GIS in the 1990s (Akcakaya, 1994). There has been considerable progress towards such integration of modelling approaches, including application to the expansion dynamics of biological invasions (Fraser et al, 2015) and species recovery (Marucco & McIntire, 2010), impacts of global change on species distributions and persistence (Keith et al, 2008;Zurell et al, 2012;Naujokaitis-Lewis et al, 2013) and evaluation of land management and conservation options (Akcakaya et al, 2004;Wintle et al, 2005;Southwell et al, 2008). The common method of hybridization is to constrain the basic demographic parameters of the dynamic model (e.g.…”

“…An individual-based modelling (IBM) approach has recently been increasingly used for dynamic modelling of species populations (Zurell et al, 2012;Aben et al, 2014;Heikkinen et al, 2014;Fraser et al, 2015). An IBM can incorporate individual variability and allow for stochastic demographic effects and explicit simulation of animal movement across realistic landscapes (Aben et al, 2014;Bocedi et al, 2014b).…”

Direct and Indirect Interactions between Landscape Structure and Invasive or Overabundant Species

“…Adapted from With [8] recognize that species responses will depend on their ecology. For example, feral cats and red foxes in Queensland, Australia were positively related to fragmented and heterogeneous agricultural landscapes [13], whereas fragmentation dampened spread of the introduced American mink (Neovison vison) in Scotland [14]. Thus, generalities about landscape structure must be considered within the context of the ecology of the species of interest.…”