Limits...
The dual role of rivers in facilitating or hindering movements of the false heath fritillary butterfly.

Fabritius H, Rönkä K, Ovaskainen O - Mov Ecol (2015)

Bottom Line: The riparian population of the false heath fritillary did not show major differences to reference populations in terms of movement parameters within breeding habitat, high-quality matrix and low-quality matrix.An artificial riparian landscape mimicking those of the coastal distribution resulted into more directional, longitudinal movements both parallel and perpendicular to the river than a more mosaic-like landscape, but the existence of the river in the landscape reduced movements across the river.As such, they can be used to compare movement parameters across populations, to study the effects of management interventions to endangered species and to identify areas that have high sensitivity to individual movement.

View Article: PubMed Central - PubMed

Affiliation: Department of Biosciences, University of Helsinki, P.O. Box 65 (Viikinkaari 1), FI-00014 Helsinki, Finland.

ABSTRACT

Background: Species movement responses to landscape structures have been studied using a variety of methods, but movement research is still in need of simple methods that help predicting and comparing movements across structurally different landscapes. We demonstrate how habitat-specific movement models can be used to disentangle causes of differentiated movement patterns in structurally different landscapes and to predict movement patterns in altered and artificial landscapes. In our case study, we studied the role of riparian landscapes to the persistence of the endangered false heath fritillary butterfly (Melitaea diamina) in its newly discovered coastal distribution region in Finland. We compared the movement parameters of the riparian population to two reference populations by using capture-recapture data and habitat-specific diffusion modelling, and analysed the role of the river and riverbank buffer zones in facilitating or hindering false heath fritillary movement with movement simulations.

Results: The riparian population of the false heath fritillary did not show major differences to reference populations in terms of movement parameters within breeding habitat, high-quality matrix and low-quality matrix. However, movement simulations showed that the habitat-specific movement parameters estimated for the false heath fritillary can lead into markedly different movement patterns in structurally different landscapes. An artificial riparian landscape mimicking those of the coastal distribution resulted into more directional, longitudinal movements both parallel and perpendicular to the river than a more mosaic-like landscape, but the existence of the river in the landscape reduced movements across the river.

Conclusions: Our study demonstrates how habitat-specific movement models enable comparisons of movement patterns across structurally different real, altered and artificial landscapes. As such, they can be used to compare movement parameters across populations, to study the effects of management interventions to endangered species and to identify areas that have high sensitivity to individual movement. In our case study, the river is shown to perform a dual role for the movements of the riparian false heath fritillary population. Whereas the river acts as a moderate movement barrier for the false heath fritillary, the longitudinal configuration of riverbank habitats provides a means especially for the male false heath fritillaries to move across the landscape.

No MeSH data available.


The effect of the river to the movements of the false heath fritillary in the study landscape. The graph shows probability of simulated male (left hand panels) and female (right hand panels) false heath fritillaries to reach a target patch (blue; pointed with an arrow, located on the Eastern side of the river) within its lifetime, as a function of its place of birth. The results are shown for the riparian landscape in which the river has been modelled as an independent habitat type (panels A-B) and another version of this landscape, in which the river has been modelled as part of the low-quality matrix (panels C-D). The difference of the probabilities (results of panels A-B minus those of C-D) has been plotted separately (panels E-F): from the green (purple) areas, the simulated false heath fritillaries are more (less) likely to reach the target patch if the river was modelled as an independent habitat type. Parameter values set to the posterior median values of the generalised movement model.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4940950&req=5

Fig9: The effect of the river to the movements of the false heath fritillary in the study landscape. The graph shows probability of simulated male (left hand panels) and female (right hand panels) false heath fritillaries to reach a target patch (blue; pointed with an arrow, located on the Eastern side of the river) within its lifetime, as a function of its place of birth. The results are shown for the riparian landscape in which the river has been modelled as an independent habitat type (panels A-B) and another version of this landscape, in which the river has been modelled as part of the low-quality matrix (panels C-D). The difference of the probabilities (results of panels A-B minus those of C-D) has been plotted separately (panels E-F): from the green (purple) areas, the simulated false heath fritillaries are more (less) likely to reach the target patch if the river was modelled as an independent habitat type. Parameter values set to the posterior median values of the generalised movement model.

Mentions: Movement simulation carried out in the riparian landscape of the riparian study area (Figure 9) visualises regions where nuanced changes in the species’ movement parameter estimates would have largest effects to estimated hitting probabilities. While differences are small between a landscape where the river was considered a distinct habitat type with its own (median) movement rates and boundary responses (panels A-B) and a landscape where the river is modelled as part of low-quality matrix (panels C-D), a more detailed comparison (panels E-F) demonstrates that they are likely to be strongest for individuals that start movement on the opposite side of the river from the target patch (decreasing their probability of hitting the target patch) and for individuals starting from the same side as the target patch but close to the opposite riverbank (increasing their possibility to hit the target patch). This demonstrates the role of the riverbends of the riparian landscapes in increasing and decreasing connectivity between habitat patches.Figure 9


The dual role of rivers in facilitating or hindering movements of the false heath fritillary butterfly.

Fabritius H, Rönkä K, Ovaskainen O - Mov Ecol (2015)

The effect of the river to the movements of the false heath fritillary in the study landscape. The graph shows probability of simulated male (left hand panels) and female (right hand panels) false heath fritillaries to reach a target patch (blue; pointed with an arrow, located on the Eastern side of the river) within its lifetime, as a function of its place of birth. The results are shown for the riparian landscape in which the river has been modelled as an independent habitat type (panels A-B) and another version of this landscape, in which the river has been modelled as part of the low-quality matrix (panels C-D). The difference of the probabilities (results of panels A-B minus those of C-D) has been plotted separately (panels E-F): from the green (purple) areas, the simulated false heath fritillaries are more (less) likely to reach the target patch if the river was modelled as an independent habitat type. Parameter values set to the posterior median values of the generalised movement model.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4940950&req=5

Fig9: The effect of the river to the movements of the false heath fritillary in the study landscape. The graph shows probability of simulated male (left hand panels) and female (right hand panels) false heath fritillaries to reach a target patch (blue; pointed with an arrow, located on the Eastern side of the river) within its lifetime, as a function of its place of birth. The results are shown for the riparian landscape in which the river has been modelled as an independent habitat type (panels A-B) and another version of this landscape, in which the river has been modelled as part of the low-quality matrix (panels C-D). The difference of the probabilities (results of panels A-B minus those of C-D) has been plotted separately (panels E-F): from the green (purple) areas, the simulated false heath fritillaries are more (less) likely to reach the target patch if the river was modelled as an independent habitat type. Parameter values set to the posterior median values of the generalised movement model.
Mentions: Movement simulation carried out in the riparian landscape of the riparian study area (Figure 9) visualises regions where nuanced changes in the species’ movement parameter estimates would have largest effects to estimated hitting probabilities. While differences are small between a landscape where the river was considered a distinct habitat type with its own (median) movement rates and boundary responses (panels A-B) and a landscape where the river is modelled as part of low-quality matrix (panels C-D), a more detailed comparison (panels E-F) demonstrates that they are likely to be strongest for individuals that start movement on the opposite side of the river from the target patch (decreasing their probability of hitting the target patch) and for individuals starting from the same side as the target patch but close to the opposite riverbank (increasing their possibility to hit the target patch). This demonstrates the role of the riverbends of the riparian landscapes in increasing and decreasing connectivity between habitat patches.Figure 9

Bottom Line: The riparian population of the false heath fritillary did not show major differences to reference populations in terms of movement parameters within breeding habitat, high-quality matrix and low-quality matrix.An artificial riparian landscape mimicking those of the coastal distribution resulted into more directional, longitudinal movements both parallel and perpendicular to the river than a more mosaic-like landscape, but the existence of the river in the landscape reduced movements across the river.As such, they can be used to compare movement parameters across populations, to study the effects of management interventions to endangered species and to identify areas that have high sensitivity to individual movement.

View Article: PubMed Central - PubMed

Affiliation: Department of Biosciences, University of Helsinki, P.O. Box 65 (Viikinkaari 1), FI-00014 Helsinki, Finland.

ABSTRACT

Background: Species movement responses to landscape structures have been studied using a variety of methods, but movement research is still in need of simple methods that help predicting and comparing movements across structurally different landscapes. We demonstrate how habitat-specific movement models can be used to disentangle causes of differentiated movement patterns in structurally different landscapes and to predict movement patterns in altered and artificial landscapes. In our case study, we studied the role of riparian landscapes to the persistence of the endangered false heath fritillary butterfly (Melitaea diamina) in its newly discovered coastal distribution region in Finland. We compared the movement parameters of the riparian population to two reference populations by using capture-recapture data and habitat-specific diffusion modelling, and analysed the role of the river and riverbank buffer zones in facilitating or hindering false heath fritillary movement with movement simulations.

Results: The riparian population of the false heath fritillary did not show major differences to reference populations in terms of movement parameters within breeding habitat, high-quality matrix and low-quality matrix. However, movement simulations showed that the habitat-specific movement parameters estimated for the false heath fritillary can lead into markedly different movement patterns in structurally different landscapes. An artificial riparian landscape mimicking those of the coastal distribution resulted into more directional, longitudinal movements both parallel and perpendicular to the river than a more mosaic-like landscape, but the existence of the river in the landscape reduced movements across the river.

Conclusions: Our study demonstrates how habitat-specific movement models enable comparisons of movement patterns across structurally different real, altered and artificial landscapes. As such, they can be used to compare movement parameters across populations, to study the effects of management interventions to endangered species and to identify areas that have high sensitivity to individual movement. In our case study, the river is shown to perform a dual role for the movements of the riparian false heath fritillary population. Whereas the river acts as a moderate movement barrier for the false heath fritillary, the longitudinal configuration of riverbank habitats provides a means especially for the male false heath fritillaries to move across the landscape.

No MeSH data available.