Rob Williams

Death is a sure thing. And, when mass mortalities happen, understanding their impact on an environment can be perplexing. This is why Dr. Jeff Tomberlin collaborated with several scientists to figure out the ecological consequences of mass mortality events and how to best minimize potential long-term negative outcomes.

The research team includes Tomberlin, as well as Drs. Marcus Lashley, Heather Jordan, and Brandon Barton at Mississippi State University. The team wanted to find out what kinds of ecological changes happen both before and during the unexpected mass mortality events, such as the 200,000 saiga antelope in Kazakhstan and more than 300 reindeer that died in 2016 from a lightning strike in Norway.

In the article published recently in the Ecological Society of America’s journal Ecology, the team studied mass mortality events and the potential effects, if any, that they may have on the environment.

Tomberlin wanted to find out if there were any ecological consequences of a mass mortality event on associated arthropod communities and how quickly the surrounding ecosystem can recover from such events. If the community cannot recover, he said that the researchers wanted to find a way to develop procedures to help reduce ecological and environmental impacts if and when a mass mortality event does occur.

In order for the team to study a mass mortality event, the researchers needed to find a way to simulate an event as predicting them is not possible for the most part. Tomberlin said they needed a mass amount of animal carcasses to view the resulting changes in the ecosystem. The group decided on using feral swine carcasses that were donated by state and federal agencies after trapping to eradicate the invasive species.

Tomberlin said the team chose to use the hogs as a model for this study because of the high availability due to the overpopulation issues that several states have seen in several states in the country. He said that the current feral hog suppression programs states employed helped make the resources needed for this study.

“Feral hogs were chosen as a model due to their availability and current issues surrounding their control in the USA,” Tomberlin said. “These two factors go hand-in-hand. Suppression of feral hog populations means resources are made available. These factors allowed to repurpose carrion to generate an artificial MME to understand how natural MMEs affect ecosystems.”

During the study, the group used more than 3 tons of hogs that were spread over five levels of land in 20-square-meter study plots over forest land that was used by Mississippi State University for research. The plots were laid out in a way to where the researchers could easily access and observe each plot for activity.

Tomberlin said they used several methods to collect the data, including molecular methods evaluating microbial communities and analyses of arthropod communities in the study area during simulation. The group also used special cameras, as well as from observations in the field. From the findings, the group found that the most abundant species that was observed were blow flies, along with the flies’ predators: green anoles and bald-faced hornets. They also saw at least 30 other vertebrate and invertebrate species that were interacting in the food web, including a rare species of wasp, as well as a beetle that has yet to be identified.

The team is still working on the ecological consequences from the simulated event but hopes to have a clearer picture on a solution to managing mass mortality events, as well as reducing the resulting the impact such events might have on the environment.

“We still do not have a complete picture of what the ecological consequences of such events are on a given environment,” Tomberlin said. “Hopefully, with additional analyses and continued research, we will have a more clear picture.”