Variations in the diurnal wintering waterbirds counts in relation to census time in the Anzali wetland, southwest Caspian Sea (Iran). - A. Khaleghizadeh. - Berkut. 19 (1-2). 2010. - P. 173-182.
In order to find variations in the number of waterbirds species between the morning and at the afternoon counts, a study has been done once every two weeks on non-hunting days from October 1999 to early April 2000 at Selkeh and Espand within the Anzali wetland complex, a habitat for wintering and passage migrant waterbirds in the south Caspian Sea. In general, most species had not higher numbers neither in the morning nor in the afternoon throughout the study period, except for Common Moorhen and Great Cormorant. Apart from Northern Pintail, other members of Anatidae, the most important family in these wetlands had a similarity of over 0.85 at Selkeh while at Espand the highest similarity of Anatidae species was seen for Mute Swan (0.98) and the lowest for Greylag Goose (0.55). Horn’s similarity index of total waterbirds between the morning and afternoon showed a similarity of 0.98 for Selkeh and 0.97 for Espand. Paired Samples t-test performed separately for all dates showed no significant difference between the total waterbirds population between the morning and afternoon counts (p > 0.05). There was no difference between Horn’s similarity calculated for the population of all waterbirds and selected common birds at Espand or at Selkeh (p > 0.05). Spearman Correlartion test showed a significant correlation between total waterbirds population and species number with waterlevel at Selkeh and Espand (p < 0.05). The test also showed a significant correlation between total waterbirds species number and population with the humidity at Espand only (p < 0.05). Regarding the main use of wetlands by waterbirds during the daytime presence of the waterbirds throughout the study period, grebes and Rallidae species, especially Eurasian Coot were observed feeding at these wetlands while Anatidae species and cormorants were using the study sites as their roost. [English].
Key words: Caspian Sea, method, count, similarity, waterbirds, number.
Address: A. Khaleghizadeh, Ornithology Laboratory, Agricultural Zoology Research Department, Iranian Research Institute of Plant Protection, P.O. Box 1454, Tehran 19395, Iran; e-mail: akhaleghizadeh@hotmail.com.