An Empirical Test of a Diffusion Model: Predicting Clouded Apollo Movements in a Novel Environment

Abstract

Functional connectivity is a fundamental concept in conservation biology because it sets the level of migration and gene flow among local populations. However, functional connectivity is difficult to measure, largely because it is hard to acquire and analyze movement data from heterogeneous landscapes. Here we apply a Bayesian state-space framework to parameterize a diffusion-based movement model using capture-recapture data on the endangered clouded apollo butterfly. We test whether the model is able to disentangle the inherent movement behavior of the species from landscape structure and sampling artifacts, which is a necessity if the model is to be used to examine how movements depend on landscape structure. We show that this is the case by demonstrating that the model, parameterized with data from a reference landscape, correctly predicts movements in a structurally different landscape. In particular, the model helps to explain why a movement corridor that was constructed as a management measure failed to increase movement among local populations. We illustrate how the parameterized model can be used to derive biologically relevant measures of functional connectivity, thus linking movement data with models of spatial population dynamics.

Successful translocation of the threatened Clouded Apollo butterfly (Parnassius mnemosyne) and metapopulation establishment in southern Finland

“…The unsuccessful site in Sipoo differed from the Porvoo site in this respect: being surrounded by more open landscape may have increased the probability of the translocated females emigrating from the suitable grassland patch where they were released. Similar effects of surrounding habitat type on emigration rate and permeability of various habitat types have been reported for several other butterfly species (Kuussaari et al, 1996;Roland et al, 2000;Ricketts, 2001;Schultz et al, 2012) as well as in the Clouded Apollo (Ovaskainen et al, 2008).…”

The role of habitat quality in fragmented landscapes: a conceptual overview and prospectus for future research

“…2. Many studies have focused on occupancy patterns and, specifically, on the role of patch quality in determining presence/absence of a species, and a few studies have focused on colonization/extinction patterns, but little has been done on the effect on dispersal patterns (but see North and Ovaskainen 2007;Rabasa et al 2007;Ovaskainen et al 2008). We do not know, for example, whether high-quality patches provide more successful dispersers/colonizers than lower quality patches; that is, whether the higher quality patches support healthier individuals that are more likely to survive the dispersal period and colonize successfully other patches.…”

Reduced Models of Algae Growth

“…Recent trends in mathematical biology indicate a shift from "soft modeling", which uses heuristical assumptions to obtain qualitative results (without quantitative crossvalidation on real data), towards "hard modeling", where parameters are estimated by fitting the model to empirical data (see Calvetti et al 2008aCalvetti et al , 2008bZheng et al, 2007;Ovaskainen et al, 2008 for some examples). The main goal of the latter approach is to produce quantitative descriptions of the behavior of the biological systems.…”