Variation of the waterbird community relying to the Ichkeul National Park, Tunisia

Abstract

For the period of 2001-2004, the detailed reaction of a waterbird community to dam building has been assessed in the Ichkeul National Park. Results showed that 71 species belonging to 8 orders were detected. Three herbivorous species were largely dominant: common coot (Fulica atra), common pochard (Aythya ferina), and Eurasian wigeon (Anas penelope). The three community parameters used in the analysis were: species richness, species abundance, and species diversity; which were significantly different between seasons. The wintering season was a key phase when the maximum values of these parameters were reached. This seasonal concentration of activity may be explained by migration. The upstream freshwater diversion was followed by a decrease in the annual abundance of the waterbird community due to the increasing salinity and the severe depletion of the swamp grass, Potamogeton (Potamogeton pectinatus). The total number of species was independent of the local conditions, and the annual variation was related to the number of uncommon species seen in each year.

Seasonal Patterns in Aquatic Bird Counts at Five Andean Lakes of Ecuador

“…The high densities of F. ardesiaca are consistent with other studies that report species of the Fulica genus as most abundant in wetlands (Hamdi et al 2008). The tendency for large piscivorous birds to increase at Yahuarcocha is noteworthy, also piscivorous species seem more abundant at this lake compared to the other lakes (c. one bird per ha at Yahuarcocha versus 0.0 to 0.04 birds per ha at the other lakes).…”

Central European Greylag GeeseAnser ansershow a shortening of migration distance and earlier spring arrival over 60 years

“…Feeding accessibility and competition may considerably affect the carrying capacity of wintering sites, particularly those where rapid human-induced changes have been recorded. Suitability for wintering Greylag Geese has probably decreased in one of the previously most important wintering sites in northern Africa, lake Ichkeul (Dick et al 1991, Hamdi et al 2008a. Similar decreases in the total number of wintering Greylag Geese in North Africa (Hamdi et al 2008b) and in the number of individuals from our study area using that wintering area support the conclusion of a long-term decrease in migration distance in this species, especially for the Central Europe/North Africa flyway.…”

“…, Hamdi et al . ). Similar decreases in the total number of wintering Greylag Geese in North Africa (Hamdi et al .…”

Selection of ecological indicators for the conservation, management and monitoring of Mediterranean coastal salinas

“…The flow of water through these ponds creates a steep and stable gradient of physicochemical characteristics, mainly salinity (Baudin 1980;Britton and Johnson 1987;Javor 1989). The spatial organization of the ponds in the salinas and of their different depths, necessary for the salt production process, favors a high degree of spatial heterogeneity and very productive microenvironments that are attractive to many primary and secondary consumers (Evagelopoulos et al 2008;Hamdi et al 2008). Such conditions are tolerated by aquatic communities with complex cycles and interspecific relationships and by species which are highly specialized for life in this environment (Geddes et al 1981;Williams 1993;Forbes and Cyrus 1993;Marín and d'Ayala 1996).…”