Tag Archives: perca fluviatilis

On Dispersal, Connectivity and the Will of the Fish

Image Credit: Dennis Jarvis, CC BY-SA 2.0, Image Cropped

Integrating dispersal along freshwater systems in species distribution models (2020) Perrin et. al., Diversity & Distributions, https://doi.org/10.1111/ddi.13112

The Crux

Trying to figure out where a species can comfortably live is one thing, but figuring out which habitats they can actually access is another. I like to think most marsupials would do quite well in South America or Africa, but the fact is that they’re not dispersing across the Atlantic or Pacific anytime soon. However a Species Distribution Model (a statistical model that can be used to predict the likelihood of a species being found somewhere) often requires a more nuanced approach than “big ocean separating these two habitats”.

To integrate a species’ ability to actually access an area into a Species Distributions Model (SDM), we often use the concept of connectivity. Often, this means simply measuring the distance between two populations. But sometimes a species ability to disperse might not reflect something as simple as how far it needs to go. A perfectly good habitat might be only 100 metres away, but cut off by a raging great cliff. Or a road.

In this study, we wanted to see whether we could relate connectivity parameters used in an SDM to the actual ability of the species to disperse.

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