Tag Archives: salamander

“Those Things Are Evil”: Prediction Intervals in Mixed Models

Suppose we study salamanders and want to predict body mass based on their body length. We also want to account for different access to food and differing levels of competition at each site we’ve collected our salamanders from. So we fit a linear model with a random effect for site as we only have samples from a subset of sites. (Want a refresher on random effects? We’ve got you covered.)

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Can Scavengers Actually Reduce Disease Transmission?

Many organisms are vulnerable to a wide array of diseases and parasites throughout the course of their lives, but could scavengers help reduce that vulnerability? (Image Credit: The High Fin Sperm Whale, CC BY-SA 4.0, Image Cropped)

Do scavengers prevent or promote disease transmission? The
effect of invertebrate scavenging on Ranavirus transmission (2019) Le Sage et al., Functional Ecology, https://doi.org/10.1111/1365-2435.13335

The Crux

As intimate as the host-parasite relationship is, it is important to keep in mind that it is embedded within a complex web of other interactions within the local ecological community. To add to this complexity, all of these interactions can feed back on and effect the host-parasite relationship. One ubiquitous part of all communities is the scavenger, an organism that feeds on dead and decomposing organisms. The authors of this paper wanted to investigate how scavengers affect disease transmission in local communities.

This question in interesting because it can easily go either way, depending on the community in question. Scavengers could lower disease transmission by eating infected organisms, thus removing contagious elements from the environment. However, scavengers could also increase transmission by promoting the spread of contagious elements in the community via their own waste after they consume infected tissues.

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