Where do we go from here? Dispersal simulations shed light on the role of landscape structure in determining animal redistribution after reintroduction

Abstract

Reintroduction projects represent viable options for animal conservation. They allow the establishment of new local populations and may contribute to recreating functional networks within a metapopulation. In the latter case, landscape connectivity may be a major determinant of the phase of spread of the reintroduced populations.Here, we deal with an example of a red deer (Cervus elaphus) translocation planned to enable the connection among existing isolated populations of the species in the Italian Alps. Our aim was to assess whether the analysis of landscape suitability and the simulation of dispersal of released individuals could shed light on the actual process of population spread. For these purposes, we adopted a modelling approach using radiotracking data to develop a habitat suitability map. On the basis of this map, we simulated the dispersal of the animals after release and we then compared the simulation results with the outcome of null models and with the observed population redistribution.The results suggest that the spread of the subpopulation was easier north-westward than southward. Taking into account landscape suitability, our simulations produced a reliable estimate of the ease of colonization of the valleys neighbouring the release-site and they allowed the identification and validation of a potential pathway for animal dispersal. The suitability model based on the monitoring of individuals in the earliest phase of establishment shed light on the spread of the population and on its potential connections with other deer subpopulations.

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

“…Advances in theoretical and empirical approaches to analysing range expansion have highlighted the importance of species interactions, evolution, long‐range dispersal events, spatial heterogeneity and temporal variability as factors that can influence the invasion process (reviewed in Hastings et al ., ). Landscape structure is particularly important (With, ; la Morgia et al ., ) as few invaded landscapes are homogeneous and geographical boundaries can restrict the extent of the invaded range. Furthermore, whereas model studies typically focus on range expansion from a single point of introduction, multiple introductions are commonplace (e.g.…”

Predicting reintroduction outcomes for highly vulnerable species that do not currently coexist with their key threats

“…The tendency of individuals to disperse is affected by the habitat matrix surrounding the reintroduction site (La Morgia et al. ), and landscape connectivity has been identified as an important factor influencing growth of reintroduced populations (Parlato & Armstrong ). Because species differ in their dispersal behavior and ability, the functional connectivity of landscape surrounding reintroduction sites (i.e., how surrounding landscape influences species movements) will be species specific (Tischendorf & Fahrig ).…”

Origins of functional connectivity in a human-modified wetland landscape

“…6). Although the importance of landscape structure on dispersal has long been appreciated in studies of terrestrial systems (Wiegand et al 1999;Ferreras 2001;La Morgia et al 2011), there has been far less research linking movement behavior with physical patterns of submerged environments (Wiens 2002;Hinchey et al 2008;Boström et al 2011). Spatial patterns of depth are likely to influence fish dispersal in a variety of contexts, because depth is related to risks of stranding and predation (Harvey and Stewart 1991) and is also associated with other important gradients, such as oxygen, light, and temperature.…”