Tag Archives: model

Model Mis-specification: All The Ways Things Can Go Wrong…

Image Credit: Grand Velas Riviera Maya, CC BY-SA 2.0, Image Cropped

In ecological studies, the quality of the data we use is often a concern. For example, individual animals may be cryptic and hard to detect. Certain sites that we should really be sampling might be hard to reach, so we end up sampling more accessible, less relevant ones. Or it could even be something as simple as recording a raven when we’re really seeing a crow (check our #CrowOrNo if you have problems with that last one). Modeling approaches aim to mitigate the effect on our results of these shortcomings in the data collection.

However, even if we had perfect data, when we decide how to model that data, we have to make choices that may not match the reality of the scenario we are trying to understand. Model mis-specification is a generic term for when our model doesn’t match the processes which have generated the data we are trying to understand. It can lead to biased estimates of covariates and incorrect uncertainty quantification.

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Using Yesterday’s Models for Today’s Conservation

Image Credit: US Fish and Wildlife Service Headquarters, CC BY 2.0, Image Cropped

Are polar bear habitat resource selection functions developed from 1985-1995 data still useful? (2019) Durner et. al, Ecology and Evolution, https://doi.org/10.1002/ece3.5401

The Crux

Ecologists often attempt to predict where species are using the spread of the resources that the species depends upon. This is done because often it’s simply easier to monitor the resources than the species. Resource selection functions (RSFs) are a tool which use the likelihood of a resource being used to predict a species distribution. However, if the landscape the resource is found in changes drastically, a resource selection function may start to be less useful.

In the early 2000s, using data collected in the 80s and 90s, US scientists developed RSFs for polar bears, a species which has regrettably become the poster child for the survival of the Arctic ecosystem. Even back then, the bears’ preferred habitat was receding. Now, with human-driven climate change severely reducing sea ice and markedly altering the bears’ habitat, this week’s authors wanted to know how well those RSFs work nowadays.

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Behavioral Ecology for the Masses

Image Credit: Thomas Haaland, CC BY-SA 2.0, Image Cropped

Previously on this site I’ve summarised an article I wrote linking some concepts from behavioral ecology with evolutionary biology. Now I’m back to say a bit more about what behavioral ecology actually is. Being introduced to the field of behavioral ecology was what sparked me to actually consider a career in science. It’s a fascinating and beautiful field, and I hope I can show you why!

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