Lake Oursi - Lake Darkoye

Year of compilation: 2001

Site description
This site consists of seven seasonal lakes, the largest of which are Oursi and Darkoye, in the Réserve Partielle du Sahel, north of the town of Gorom-Gorom. The westernmost, Tin Edia, is located at the foot of hills, Oursi, the largest, is at the base of old sand-dunes, while the others, Darkoye, Kouyéra, Yomboli, Kissi and Bangao, occur in open steppe, to the west of the town of Markoye. Also included is the habitat between the lakes which includes sand-dunes (such as at Oursi), semi-desert grasslands, open eroded shields, drainage lines, inselbergs rising out of the plains and a series of hills. Depending entirely upon the annual run-off from the rains of July to September, lake levels vary considerably from year to year. Some lakes are ringed by important stands of trees such as Acacia albida and Ficus sp. On the seasonal flood-plains there is a rich plant community, including Aeschynomene lotus and the sedges and grasses Cyperus alopecuroides, Echinochloa stagnina, E. pyramidalis and Oryza longistaminata, providing important dry season grazing.

Key biodiversity
See Box and Table 2 for key species. Large numbers of Palearctic migrants use the lakes annually. At Oursi and Yomboli, 106 species of waterbird have so far been recorded (47 Palearctic and 59 Afrotropical). In 1998 counts for Lake Oursi alone totalled 20,000. The continued presence of Struthio camelus is reported by poachers.

Non-bird biodiversity: Mammals of global conservation concern include Gazella rufifrons (VU) and Acinonyx jubatus (VU) (continued occurrence requires verification).

Pressure/threats to key biodiversity
The area lies within the Réserve Partielle du Sahel and Lake Oursi is a Ramsar Site, at which hunting has been banned (a ban largely respected by legal sport hunters) since the 1970s. Currently this IBA, along with the Béli river (IBA BF001), is the most threatened in the country due to the increasing human pressures around most of the lakes in the complex. Activities include vegetable gardening, the harvesting of Nymphaea, hunting, uncontrolled fishing, cutting of firewood and livestock-grazing. Additionally, the lack of viable management planning or action in the field, the shortage of Direction Général des Eaux et Forêts staff (two only for the whole region) and difficulties in establishing the boundaries of the conservation area, hinder effective conservation. The government is, however, establishing a management system for the Lake Oursi area while the forthcoming PRONAGEN will include the site.

Recommended citation
BirdLife International (2022) Important Bird Areas factsheet: Lake Oursi - Lake Darkoye. Downloaded from on 02/12/2022.