Résumé:
The eco-ethological study of five regular breeding avian species in Algerian wetlands belonging to the Phœnicopteridae (the Greater Flamingo Phoenicopterus roseus) and breeding Anatidae families (the Mallard Anas platyrhynchos, the Ferruginous Duck Aythya nyroca, the White-headed Duck Oxyura leucocephala and the Marbled Teal Marmaronetta angustirostris) in their favorable environments.
The study of the diurnal behavior of these five species showed that our wetlands play a dual role for this aquatic avifauna: a feeding ground for the Greater Flamingo and the Marbled Teal, and a staging ground for the Mallard, the Ferruginous Duck and the White-headed Duck.
During the 2021/2022 season, the Greater Flamingo was very abundant in two Saharan wetlands (Lac El-Goléa: Ghardaia and Chott Oum Raneb: Ouargla). The maximum number of individuals recorded was 7500. This wader's diurnal balance was dominated by feeding (73% in Chott Oum Raneb and 74% in Lac El-Goléa). Other activities (swimming, grooming, courtship, sleeping and flying) were observed at low rates. For the Marbled Teal, during three monitoring seasons (2020/2021, 2021/2022 and 2022/2023) at Chott Oum Raneb, the total number of this species, considered rare, exceeded 200 individuals. Its diurnal behavior is dominated by increased feeding activity, which accounts for between 43 and 46% of the total count.
In Lake Tonga and during three monitoring seasons (2020/2021, 2021/2022 and 2022/2023), the maximum Mallard population recorded was 1306 individuals. Total diurnal activity is dominated by feeding activity, which accounts for over 40% of the total. In five wetlands along the country's eastern coast (Lake Tonga, Lac des Oiseaux, Marais de la Mékhada marsh, Lake Fezzara and Garaet Hadj-Tahar) and during two study seasons (2021/2022 and 2022/2023), the Ferruginous Duck was also very abundant. Its numbers reached 790 individuals in these hydrosystems. Its diurnal behavior is dominated by sleeping, which varies from 46.17% at Garaet Hadj-Tahar to 50.17% at Lac Fezzara. While during two study seasons (2020/2021 and 2021/2022) at five High Plateau wetlands (Garaet Timerganine, Garaet Ouled Amara, Chott El-Hodana, Barrage de Bouguezoul and Barrage de Bougara), the White-headed ducks were observed in very large numbers, often fluctuating between 50 and 200 individuals. The balance of their diurnal time budget is dominated by sleeping, which accounts for between 39 and 53%, except at the Bougara dam, where the diurnal balance is dominated by feeding, often at a rate of 40%.
It should also be noted that the quality and nature of the water, as well as the depth of these aquatic ecosystems, exert considerable effects on the hosting and monitoring potential of these avian populations.
