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The quest to revive extinct Aurochs to restore ancient lands

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Rewilding and restoration of land often rely on the reintroduction of species. But what happens when what you want to reintroduce no longer exists? What if the animal in question is not only locally extinct, but gone for good? Yes, this might sound like the plot of Jurassic Park. But in real life this is actually happening in the case of the Aurochs ( Bos primigenius ). This wild ancestor of all modern cattle has not been seen since the last individual died in 1627 , in today’s Poland. Aurochs have been deep within the human psyche for as long as there have been humans, as attested by their prominence in cave art. However, the advent of agriculture and domestication put the magnificent animal on a path to extinction. So why bring the Aurochs back today and how? And what is the likely outcome? What is left of Aurochs, besides their depiction in cave paintings, are some fossil remains and some descriptions in the historical record. “Their strength and speed are extraordinary,” w
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Ancient African herders had lasting ecological impact on grazed lands

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Ancient animal herders added to the ecological richness and diversity of the African savanna thousands of years ago -- an effect that persists to the present day, a new study finds. The herders' practice of penning their cattle, goats and sheep at night created nutrient-rich grassy glades, called hotspots, that still attract wildlife and have increased habitat diversity in the region, researchers report in the journal Nature.

Typically, the African savanna is scrubby, with small trees and shrubs and lots of bare soil, said University of Illinois anthropology professor Stanley Ambrose, who led the new research with Fiona Marshall of Washington University in St. Louis. The herding hotspots appear on the landscape today as dense, grassy areas several acres in diameter, he said.

"When Stone Age herders came to eastern Africa 3,500 years ago, they changed vegetation patterns for the better, rather than degrading the savanna, as is often believed," Ambrose said. "Their abandoned settlements increased savanna grassland ecosystem diversity, resilience and stability."

To understand the long-term contributions of ancient pastoralists, the researchers focused on five Neolithic herder archaeological sites in southwestern Kenya and compared their plant communities and soil chemistries with natural sites nearby. Radiocarbon dating indicated that the herding sites date to between 1,500 and 3,700 years ago.

The team used a variety of techniques to analyze archaeological sediments, including chemical composition analyses, isotope ratio mass spectrometry, sedimentology and microscopic morphology. This allowed them to differentiate the soil characteristics of sites that were and were not used by animal herders.

Study co-authors Ruth Shahack-Gross of the University of Haifa and Rachel E. B. Reid of Washington University found that, compared with other locales, the ancient herding sites had elevated levels of nitrogen and mineral nutrients, especially phosphorus and calcium. The chemical varieties, or isotopes, of nitrogen and carbon on the pastoral sites were consistent with those found in dung and urine from herbivores that graze on grasses.

"Phosphorus originates from the organic component of dung," Shahack-Gross said. "Calcium carbonate -- like that found on the herder pen sites -- is concentrated in decomposed dung in the form of tiny particles called spherulites."

"Bones also are sources of phosphate, magnesium and calcium, all of which we found at higher concentrations in the soil of the ancient herding sites," she said.

All of these characteristics would improve soil fertility and promote the growth of high-quality forage in these limited patches, the researchers said.

"Without this human-induced increase in diversity, the landscape would lack hotspots of this scale," Ambrose said. "The largest hotspots would have been only a few meters across, centered on termite mounds. The vegetation patterns would have been much more uniform, and the ecosystem would have been simpler and less resilient."

The biological richness of the pastoral sites continues to attract animals to these locales, reinforcing their status as nutrient-rich patches, Ambrose said.

"These hotspots are preferred feeding areas for both wild and domestic herbivores," he said. "The animals often feed there early in the day and get a nutritious breakfast that helps sustain their energy throughout the day."

The continued deposition of dung and perhaps even the wild animals' grazing behavior likely lead to feedbacks that further enriched the sites, he said.

"Our study indicates that herders may have had a role in structuring and diversifying African savanna ecosystems for up to three millennia," Ambrose said.

A Washington University I-Cares grant supported fieldwork for this study. The National Science Foundation supported the laboratory research.

Image: Researchers can date the archaeological skeletal remains, including this cow tooth from the oldest herder site in this region, to determine when herding sites were used.
Credit: Photo by L. Brian Stauffer

Story Source:
Materials provided by University of Illinois at Urbana-Champaign. Original written by Diana Yates. Note: Content may be edited for style and length.

University of Illinois at Urbana-Champaign. (2018, August 29). Ancient African herders had lasting ecological impact on grazed lands. ScienceDaily. Retrieved September 11, 2018 from www.sciencedaily.com/releases/2018/08/180829133234.htm

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