Nomadic herders, specifically in Africa's arid Sahelian region, bear a particularly painful burden from coronavirus, as they watch their animals suffer due to lack of pasture land and a halt in trade activities.

For centuries, herders have moved hundreds of miles every year, especially during April and May, to find pasture for their herds. Mauritanian herders, for example, head to Mali and Senegal in search of pasture.

However, due to border closures by governments across west and central Africa to curb the spread of coronavirus, which has so far infected over 600,000 people in the continent and killed over 13,000, herders and cattle who took to the corridor between Mauritania and Mali during the lean season are stranded in border areas without resources for their livestock.

Aliou Hamadi, coordinator of the Groupement National des Associations Pastorales, a Mauritanian herders association, said herders can no longer travel to Mali and are deprived and stranded at the border.

"A large concentration of herders has been reported in the commune of Adel Bagrou, on the border with Mali," Hamadi said.

Hamadi said the presence of thousands of herders along the small border areas has led to mixing of livestock and created tensions between them, especially at water points.

"The impact of this situation on livelihoods and cattle health is also considerable," he said.

To monitor the situation and better address the needs of stranded herders, the International Organization for Migration conducted a flow monitoring survey between May and June 2020.

The organization learned a sizeable minority of herders, 16 percent, were unaware of preventive measures to ward off the disease.

To address this deficit, the organization launched an awareness-raising campaign to combat spread of the virus and installed hand-washing facilities in areas where herders have been stranded.

Babiyé Balemine, who participated in the survey, said currently there is a lot of green grass on the Malian side.

"Mauritanian herders used to go there, but the closure of the borders is disrupting this flow. The Mauritanian government offers feed to livestock farmers, but it is not enough," Balemine said.

He said tensions are compounded by health risks due to the current coronavirus pandemic.

"Many Malian and Mauritanian herders do not distinguish the territories on which their cattle graze. These are roads people have traveled for years and years," Belamine said.

Since February 2019, the International Organization for Migration has been working in partnership with the Groupement National des Associations Pastorales to better understand transhumance corridors through its Transhumance Monitoring Tool.

A transhumance corridor is a strip of land reserved for livestock passage to access pasture, a source of water or other herd infrastructure such as a livestock market, vaccination area or livestock holding area.

The Transhumance Monitoring Tool methodology consists of collecting information on large and sudden population movements, their direction and challenges faced by herders.

The information is collected directly from transhumant herders, notably through community relays.

Western and central Africa are considered pastoral, with approximately 13 percent of inhabitants being nomadic or semi-nomadic.

The Sahel covers about 5.7 million hectares between the Sahara and the wetter savannah to the south.