Environmental Change And Extinction Predictions
An Environmental Article from All-Creatures.org

From

Faunalytics
March 2016

Based on the results, it looks as if there is indeed a correlation between temperature change and animal populations. The "rate and direction" of temperature change altered the way that population declined in a rather simple way: "warmer treatments produced faster rates of extinction, and cooler treatments produced slower rates of extinction."

African Wild Dog

Measuring extinction can be a difficult thing. In general, wildlife monitoring is hard to do accurately, but extinction in especially difficult because it often involves trying to measure the absence of species rather than their presence. This means that many "historic extinction events" and the conditions that led to them have been "inferred, rather than observed directly." It is especially difficult to measure when species survive for a very long time with low numbers compared to species that experience a quick drop.

That being said, whenever we attempt to monitor a species in decline we also need to consider a range of factors including environmental conditions. Whether the conditions are biotic, "such as an invasive species or disease," or abiotic, "such as temperature change or habitat loss," these factors can increase the rate of decline. This, in turn, can affect our ability to judge how quickly the decline is happening.

In this study, researchers wanted to quantify how much environmental factors can play into the rate of species decline, and how that can "alter one’s ability to infer whether a species is extinct is of concern." To that end, they ran experiments and then replicated the same analysis for eight historic "wild population extirpations" to see if the experimental results could apply to real world data. More specifically, the experimental data were gathered from "replicate populations of the bactiverous ciliate Loxocephalus sp., which were subjected to various rates of temperature change through time." For the wild populations, data were gathered from a variety of sources of published literature.

Based on the results, it looks as if there is indeed a correlation between temperature change and animal populations. The "rate and direction" of temperature change altered the way that population declined in a rather simple way: "warmer treatments produced faster rates of extinction, and cooler treatments produced slower rates of extinction." Of course, these links had an effect on how accurately species declines could be predicted: in their calculations, the researchers noted that "mean error of estimates tended to be higher in cooler treatments and lower in warmer treatments," and "all methods showed a decrease in the mean error of underestimates at warmer temperatures."

The researchers also found that, when it came to monitoring wild animal populations and applying these techniques, there were some obvious challenges. The accuracy of predictions was affected by the methods used and how much data could be collected based on species sightings. For wildlife advocates, as well as researchers and others who study wild animal populations, the results indicate that environmental change can have a direct impact on the accuracy of species decline predictions. That said, if we want to be effective in our advocacy for wild species on the brink, then we need the best possible data and predictions available.

Access the entire study: Environmental Change And Extinction Predictions

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