Environment shapes gut bacteria of Etosha herbivores ^{CEFR B2}

Researchers investigated how environmental conditions shape the evolution of gut bacteria in wild African herbivores. They worked in Etosha National Park, Namibia, a relatively dry ecosystem, and collected fresh feces from 11 herbivore species. The samples came from animals such as African elephants, Angolan giraffes, wildebeests, two zebra species and several antelope species. DNA extraction and sequencing were used to identify the bacterial taxa and their relative abundances in each sample.

The study tested for phylosymbiosis, the expectation that related host species harbour similarly related gut microbial communities. Results revealed a contrast across species: six species showed little or no evidence of phylosymbiosis, while five species displayed patterns consistent with it. Those five species are:

• red hartebeest
• blue wildebeest
• gemsbok
• impala
• springbok

All five are bovids, a closely related group of ruminant, cow-like herbivores with complex stomachs, so the finding aligns with shared evolutionary history. The authors note that earlier work in more temperate African ecosystems did not find phylosymbiosis among bovids. They suggest local environment can mask or reveal such patterns: wetter areas with diverse vegetation may support greater gut microbial diversity and create background variation, while dry sites like Etosha may remove microbes not well adapted to the hosts or limited vegetation, making host-related patterns easier to detect. The team adds this pattern may be particularly clear for bovids and could matter as many ecosystems become drier with human-mediated climate change. The paper appears in BMC Ecology and Evolution, with additional coauthors from Etosha Ecological Institute and the University of Georgia.