Search Results

1 - 2 of 2 items

  • Author: Mohamed Dhaya El-Hak Khemis x
Clear All Modify Search

Abstract

Providing a live data monitoring of raptor abundances and spatial localization of their most important nesting areas is very helpful in building a strong future study and applying a sound strategy for effective safeguarding of these emblematic species. Using geographic information system (GIS) and global positioning system (GPS) techniques, we investigated spatial patterns of raptors distribution in the northeastern areas of Algeria during two consecutive breeding seasons (2014 and 2015). The total area sampled (31,000 km2) host diverse raptor species (14 species), among them, the threatened species Egyptian vulture (Neophron percnopterus; 108 individuals and 19 active nests) and red-footed falcon (Falco vespertinus; 12individuals). The value of the region is attested by the presence of an abundant population of nesting black kite (Milvus migrans; 337 individuals). The large-scale spatial analyses of the studied region illustrate certain similarities in nesting habitat selection among raptors. Almost all species (90% of 209 nests detected) preferred to nest within multispecies assemblages (20 raptor assemblages found) and occupied altitudinal rocky cliffs across the inland region (semi-arid zones) rather than coastal region (sub-humid zones). Among all raptor species, exclusively, the common kestrel (Falco tinnunculus) is relatively synanthropic, because it was found to breed within cities (tolerate human activities). The raptor community in the coastal versus inland regions differed by 14%. The latter area seems to be more preferred in nest building, probably consequence of their semi-arid bioclimatic and landscapes characteristics, where high elevations and grasslands forming mosaics with Oak, Alpine, and Cedar forests are patchily distributed. The study is a first mapping database of important nesting sites dispatched across the northeastern areas of Algeria, and it can be effectively used in future complementary researches that aim to elucidate environmental factors that affect raptors life cycle.

Abstrat

Recently, Mediterranean coastal lagoons have raised considerable environmental concerns. Long-term studies of seasonal changes in waterbird assemblages are therefore extremely important in terms of ecological relevance and conservation of these sensitive ecosystems. An ornithological survey of four years was carried out in a typical costal wetland (El Mellah lagoon) of Northeastern Algeria. Intra-seasonal comparison of waterbird assemblages (diversity indices) demonstrates clear changes between the wintering and the breeding periods. It seems that the first one was rich in term of species number than the second season (43 against 24). In contrast, the breeding seasons were more equilibrate (high values of Simpson, Shannon and evenness index). Additionally, curves in the diversity/dominance diagram revealed that both wintering and breeding assemblages share the same characteristics of community structure, few dominant species (with intermediate relative abundance) and many rare species with the relative abundance lower than 0.1. Invertebrates (25 species) and piscivorous (11 species) are the most abundant guilds over the four years of study (no significant differences among years have been calculated). The marked decline in bird species diversity recorded in this study (in comparison with previous studies) is mainly due to salinity oscillations (due to aquaculture activities) and may be of concern to wetland managers and it might be useful to provide some guidelines about the characteristics that coastal lagoons have to follow in the construction process to enhance the biodiversity.