Table 1 Sampling sites [21]

Soudanian zone

N’Dorola

11°46’N;

4°49’W

Dingasso; N’Dorola

1350–1500

Gaoua

10°20’N;

3°10’W

Gaoua; Oukouéra

1050–1200

Batié

9°52′60’’N;

2°55’W

Maal-Sourgoen; Bakon

1350–1500

Soudano-sahelian zone

Tougan

13°4’N;

3°4’W

Nassan; Yéguéré

750–900

Yako

12°57’N;

2°16’W

Moutoulou; Yako

900–1050

Boulsa

12°39’N;

0°34’W

Boulsa; Kobouré

600–750

Sahelian zone

Bogandé

12°58′1’’N;

0°9’W

Bogandé; Nindangou

600–750

Mani

13°15′30’’N;

0°12′47’’W

Mani; Toabré

600–750

Dori

14°1′59’’N;

0°1′59’’W

Dori Sector 3; Dori Sector 7

450–600