| The Dagujia River estuary in Yantai is located on the East Asia-Australia migration line.It provides habitat and energy compensation for migrant birds,and is an important migration route for birds.However,there is little literature on bird diversity,and the systematic investigation of waterfowl community in Jiahe estuary is even more important.Due to the rapid development of economy in recent decades,some changes have taken place in the habitat of the estuary,which makes the water bird community structure have a great change.In order to further understand the abundance of waterfowl in this area,the community composition and feeding behavior of waterfowl in Dagujia River estuary were studied from October 2016 to November 2018.The results are as follows:The water bird community in Dagujia River estuary wetland of Yantai was observed from October 2016 to September 2017 by using the method of sample line and direct counting.52 species of water bird were recorded in 5 orders,10 families and5 orders.The survey found that 5 species of native birds accounted for 10% of the total species and 47 species of migratory birds accounted for 90.0%.22 species of migratory birds accounted for 44.0%,15 species of winter migratory birds accounted for 30.0%,and 8 species of summer migratory birds accounted for 16.0%.Twelve dominant species were Gray Heron(Ardea cinerea)?Little Egret(Egretta garzetta)?Common Shelduck(Tadorna tadorna)? Common Mallard(Anas platyrhynchos)? Common Pochard(Aythya ferina)? Tufted Duck(Aythya fuligula)? Common Goldeneye(Bucephala clangula)?Snowy Plover(Charadrius alexandrines)?Whimbrel(Numenius phaeopus)?Black-tailed Gull(Larus crassirostris)?Larus argentatus(Larus vegae)and Common Black-headed Gull(Larus ridibundus).From the ecological point of view,wading birds accounted for 62.0% of the total species,and swimming birds accounted for 38.0%.One species of Oriental White Stork is listed as the first-class protected bird in this record,and eight species of threatened birds are listed in the World Union for the Conservation of Nature(IUCN).The season alvariation curve of waterfowl species number had two peaks in April and September,21 and 19 species respectively,and the lowest in June,only 9 species were recorded.There was a big difference between the individual population dynamic curve and its species number dynamic curve,showingthree peaks on the whole,the highest in March,then in January and October,and the lowest in May and June.A-diversity analysis showed that waterfowl were more abundant in autumn and winter than in spring and summer.In March-June and August-November 2018,41 species of waterfowl belonging to5 orders,8 families and 41 species were surveyed in the wetland during the migration season of Dagujia River estuary.There are 36 species of migratory birds,accounting for 88.0% of the total species.Among them,21 species of migratory birds account for54.0%,8 species of winter migratory birds account for 19.0%,and 7 species of summer migratory birds account for 15.0%.Eleven species of breeding birds(summer migrants and resident birds)accounted for 27.0%.From the point of view of life type,wading birds account for 71.0% of species and 29.0% of species.The largest number of recorded species is the Mugiformes,with 26 species accounting for 63.4% of the migratory waterfowl species in the area.There are eight dominant species of parrots,namely,Little Ringed Plover(Charadrius dubius),Snowy Plover,Middle-rowed Parrot,White-waisted Parrot(Numenius arquata),Three-toed Parrot(Calisris alba)and Black-bellied Parrot(Calrisidalpina).Spring migration season began in mid-March,and Snipes began to come to this place to feed and inhabit,reaching the maximum number of species in early April and May,during which water birds migrated and moved in,and then moved out in mid-late May.In autumn migration season,Snipes migrated in succession from late August,reached the maximum in early September and October,and moved out in early and mid-November.Bird richness in autumn migration season is higher than that in spring migration season.The inter specific correlation analysis of 13 species of snipe water birds showed that 9 pairs of them showed significant correlation.From November 2017 to February 2018,a supplementary survey was carried out on wetland water birds in the Dagujia River estuary during the wintering period.During the wintering period,the composition of water birds was 24 species,7 families and 5 orders.There are 18 species of migratory birds,accounting for 75.0% of the total species.Among them,13 species of winter migratory birds account for 54.0%,3species of travelling birds account for 12%,and 2 species of summer migratory birds account for 8.0%.From the point of view of life type,wading birds account for 29.0%of species,and swimming birds account for 71.0% of species.The most abundant order in the record is Passeriformes,accounting for 42.0% of the waterfowl species in the wintering season.Compared with the wintering period 2016 to 2017 and 2017 to 2018,the species number and species number in the wintering period 2016 to 2017 are much higher than those in the wintering period 2017 to 2018,and the diversity in 2016 to2017 is higher than that in the wintering period 2017 to 2018.Inter specific correlation analysis of population size of 8 species of duck waterfowl with time showed that 12 pairs of them showed significant correlation.The migration pattern of Ducklings is relatively single.Large-scale migration began in early November to the Dagujia River estuary,reaching its maximum in January,and evacuated completely in early April of next year.In March,May,September and November 2018,the bottom air biology of Dagujia River estuary beach was investigated and the feeding behavior of parrots was observed.Benthic fauna 4 classes,respectively,are crustacea,polychaete,gastropoda,bivalves.In terms of species number,Crustacea and Bivalvia have the largest number;in terms of quantity,Crustacea has the largest number in spring migration season,while Polychaete has the largest number in autumn migration season.The results of Mann-Whitney U showed that there were significant differences between spring migration season and autumn migration season in Crustacea,Gastropoda and Polychaete except Bivalves.The predatory behavior and feeding frequency of dominant waterfowls were observed in Dagujia River estuary wetland.The results showed that Middle-rowed Parrot,White-waisted Parrot,Three-toed Parrot and Black-bellied Parrot belonged to tactile continuous feeding strategy with high feeding frequency,Snowy Plover and Little Ringed Plover belonged to running-stop(pause-travel)feeding strategy with low feeding frequency. |
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