Little is known about the effects of waterbirds on benthic macroinvertebrates in nontidal habitats. We conducted 4 waterbird-exclusion experiments in a transformed marshland in Doñana Natural Park (southwestern Spain) and compared benthic macroinvertebrates in 3 × 3-m control (no exclusion) and test plots from which Greater Flamingos Phoenicopterus ruber or all waterbirds were excluded. The 4 experimental periods coincided with the waterbird breeding season (summer), postbreeding period (autumn), wintering period (winter), and pre- and early breeding season (spring). Densities of waterbirds were relatively low compared to densities reported in other studies, but we found strong effects of excluding flamingos and waterfowl on the structure of the benthic community in autumn, winter, and spring. In winter, numbers of polychaetes and chironomids were nearly 2× higher in exclusion than in control plots. The difference in macroinvertebrate biomass among treatments was strongest in winter when benthic dry mass was ∼2× higher in flamingo exclosures than in control plots and ∼2× higher in all-bird exclosures than in flamingo exclosures. Macroinvertebrate richness was 15% lower in control than in all-bird exclosures in winter and 25% lower in control than in all-bird exclosures in spring. Our results suggest that benthic macroinvertebrate communities in this wetland are affected more by predation, bioturbation, and waterbird herbivory than by competition. These findings suggest that waterfowl and the increasing population of flamingos are of great importance in structuring shallow lakes in the Mediterranean region.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.