The synanthropic Common Moorhen (Gallinula chloropus) in North Africa: The Impact of habitat degradation on breeding performances

We carried out a study on dynamics of the Common Moorhen, Gallinula chloropus, a synanthropic rallid (Aves, Gruiformes), to elucidate the adverse effects this species has possibly suffered from the markedly increased habitat degradation that has been taking place over the last decades at Boussedra Pond, north-eastern Algeria. During the period 2015–2018, this wetland-related species showed an annual 35.4% decrease in its numbers, and the number of breeding pairs, which was monitored between 2008 and 2018, experienced an annual drop of 4.9%. The clutch size, a key determinant of breeding performance, averaged 4.7 ± 1.0 eggs (N = 26 clutches) in 2018 and was significantly lower than those reported in previous studies. As a result of anthropogenic activities, the size of the marsh decreased by more than 50% over the 1984–2018 period. The long-lasting shrinkage of this relict wetland was accompanied by the expansion of built-up areas (>50%) and cultivated plots, and, also, by a marked reduction in natural both wet- and dry-land habitats in its vicinity. We suggest that the decrease in the population trend and the breeding performance of the Common Moorhen could be indicative of the species stress response to the long-lasting land conversion, pressuring the relict habitat of Boussedra Pond.