Influence of temperate zone wetlands drying and overgrowth on bird diversity and abundance

Wetlands, the essential ecosystems, contain plenty of animal and plant species. Due to their various types and characters, wetlands support very different organisms, especially birds. Animals are thanks to their adaptation made for life in water, and some species are water-dependent - they use wetlands to forage and as breeding sites or nesting sites. Birds, and mainly waterbirds, require var- ious habitat characteristics because some of these habitats are due to bird diverse ecology suitable just for a few bird species. Wetlands drying and overgrown is a major threat for these ecosystems, and they are influencing birds in different ways. The efficiency of hunt or food availability may be affected by both changes in water depth and the density and extent of vegetation. These variables have a diverse effect on nesting birds, firstly on habitat selection for nesting and secondly on nesting success and survival mainly because of predators, because predation tends to be increasing with decreasing both water depth and nest cover. In terms of possible wetland management and restora- tion, we have to remember that we cannot generalize these effects for all bird species. Possibilities are creating new wetlands or restoration, such as vegetation cutting, burning, and livestock grazing. These options bring...