Rylee Jensen, a recent master’s graduate from Northern Michigan University, recently authored the coolest of these studies. This study investigated the gut microbiomes of several diverse herbivorous species from multiple sites in Etosha National Park, Namibia. This research couldn’t have arrived at a more opportune time as the park is currently battling catastrophic wildfires that endanger its ecosystem. This research is set in arguably Africa’s most important wildlife sanctuary. It uncovers important information about how environmental factors shape the gut ecosystems of elephants, giraffes and other herbivores.
The research team collected new feces samples from a large and diverse group of herbivores. This colorful menagerie featured African elephants, Angolan giraffes, herefeld’s wildebeests, two species of zebra, and numerous antelope species. The researchers compared the samples to understand how environmental factors impact the gut microbiomes of these fascinating animals. Their hope was to identify the complex dynamics operating beneath the surface.
Methodology and Findings
Based on yearly rainfall patterns, the researchers split Etosha National Park into three unique areas. This plant division provided the researchers to see differences in diversity and abundance of plants throughout other regions within the park. Remarkably, of the eleven herbivore species nine flourished in all three zones. This abundance in turn led to an attractive dataset for microbiome analysis.
We ended up with 312 fecal samples across the 11 species, which gave us a wealth of microbiome data, and our analysis gave us a deeper understanding of the variables that can influence these microbial ecosystems,” stated Rylee Jensen. The researchers were able to define 22 core types of core bacteria. Of these, they confirmed that 20 of these types tend to be common across multiple species. Elephants were notable in carrying two categories of core bacteria absent in the core of other herbivores.
The study further stressed that the relative abundance of five specific microbes changed in a predictable pattern within the continuous zones. While these results are initially surprising, they provide clarifying insight into the factors shaping gut microbiomes. They provide insight into how ecological factors and anatomical adaptations may lead to variation across herbivorous taxa.
Implications for Conservation
Erin McKenney, assistant professor of applied ecology at North Carolina State University and co-author on the paper. She stressed the importance of this research as we continue to grapple with worsening environmental health effects. “This study is valuable because Etosha gave us the opportunity to sample such a large number of species under different environmental conditions,” she explained.
She further noted, “Unfortunately, this study may be important for a second reason. Etosha is experiencing devastating wildfires affecting a huge section of the park. Because our samples were taken before the wildfires, these findings could inform recovery efforts by helping us understand how species’ microbiomes are adjusting to changes in diet that stem from the fire’s impact on the landscape.”
Diana Lafferty, an associate professor of biology at Northern Michigan University, is one of the study’s co-authors. She’s hopeful about its potential to make a real impact. “We’re excited about this work, in part, because we were able to collect high-quality samples from species in a region that had not previously been sampled for gut microbiome studies, and we got very fine resolution data,” Lafferty stated.
Establishing Baselines for Future Research
This study lays an important baseline for monitoring changes in the gut microbiomes of these closely-related species over time. “And we’ve essentially established a baseline that can be used to help us understand any changes we see in these species in this region,” Lafferty added. This baseline is extremely important as many of these herbivores are keystone species in their respective ecosystems. Gut microbiomes perform critical functions that impact animal fitness.
Rylee Jensen pointed out one particularly intriguing finding: “One of the most interesting findings was that there were five types of bacteria that served as environmental indicators.” She elaborated on their significance: “Specifically, the relative abundance of these five microbes varied in a predictable way from zone to zone.” Though not the most glamorous or cuddliest microbes, these little guys are fantastic at digesting lipids. They change fiber into forms of nutrients that animals are able to quickly digest. This is super interesting stuff! These operational environmental indicators may be extremely useful for tracking trends in our ecosystem and determining how animal species are responding to those changes.