Author(s): Armengol, X., Antón-Pardo, M., Atiénzar, F., Echevarrías, J. L. & Barba, E.
Title: Limnological variables relevant to the presence of the endangered white-headed duck in southeastern Spanish wetlands during a dry period
Year: 2008
Volume: 54
Pages: 45-60.
Abstract: We have studied the distribution of the white-headed duck (Oxyura leucocephala), an endangered diving duck, living in wetlands in Alicante (southeast Spain). Coordinated with these observations, we made a limnological characterization of the water and sediment of several lakes within these wetlands, selecting those both with the presence and absence of the duck. Limnological variables analyzed included those related with the trophic status (water transparency, dissolved nutrients in the water, and chlorophyll a concentration), those related with the water mineralization, depth, macrophyte cover, and potential food items in the sediment (mostly chironomidae larvae and macrophyte seeds). The study was done during a dry period (spring and summer of 2005). In the examined period, a large reservoir (which was the preferred place by white-headed ducks in previous years) dried out in spring. Consequently, the population of white-headed ducks in the area was much lower and the birds distributed themselves among other water bodies in the surrounding wetlands. Using the limnological variables, we performed a Principal Component Analysis (PCA). The first, but especially the third factor, extracted from the analysis showed an ordination of the samples which separated the water bodies where the duck was present. Correlated with these factors, we have found variables regarding morphometry, trophic status, and food availability in the sediment of the lakes. Under these conditions of severe drought, white-headed ducks were distributed preferably in deeper lakes with more chironomid biomass, and also in lakes with a lower macrophyte cover and greater turbidity. Within the range of conditions available, the ducks did not show preferences for salinity and they were found from mesotrophic to hipertrophic waters.
Keywords: habitat selection, White-headed duck, endangered species, dry period
Journal: Acta Zoologica Academiae Scientiarum Hungaricae
Journal abbreviation:
ISSN: 1217-8837
Publisher: Hungarian Natural History Museum, Budapest
Editor(s): Bakonyi, G., Mahunka, S., Papp, L., Báldi, A., Csuzdi, Cs., Forró, L., Andrikovics, S. & Kerekes, J.
