| Duck species represent the greatest number of waterbirds in the world,with the largest population reduction.According to the study,nearly 80%of the duck species overwintered in the Yangtze River Basin,so it was necessary to protect them there.In addition,overwintering had an important influence on the life activities of duck species.The loss or destruction of overwintering land affected the reproductive activity of duck species the following year,and even caused death.Duck species is the major natural hosts of avian influenza virus.Their migration was the main cause of the rapid spread of avian influenza worldwide.At the same time,some duck species had the potential to mix with poultry or feed in house.It was therefore easy to spread avian influenza viruses from wild ducks to poultry and populations,thereby endangered human life and caused significant economic losses.Shanghai was in the East Asia-Australia migratory route,and the proportion of migratory birds was high.Duck species was one of the largest groups of migratory birds in Shanghai.Recent studies had shown that duck species in Shanghai frequently use farmland and rivers near the tidal flat and living environment of the reclamation area,which is not conducive to the long-term survival of duck species and the prevention and control of wild animals in Shanghai.In this study,Anas zonorhyncha and A.platyrhynchos,not only with a large population and high rate of avian influenza virus infection,but also with poultry ancestors,were selected as the research objects.The habitat selection and wintering behavior of the two duck species were studied using GPS biological tracker and infrared camera methods.At the same time,the relative risk map of avian influenza transmission was drawn to monitor the risk of avian influenza virus infection in Shanghai.The main results are as follows.1 From 18 January 2017 to 1 November 2021,a total of 71 GPS trackers were installed in the Pudong Dongtan and Jiuduansha Wetland National Nature Reserves,Shanghai.Twenty-six northern migration routes were confirmed,and the annual migration routes of three A.zonorhyncha were recorded.There were three main migration routes:(1)Shanghai→Shandong,(2)Shanghai→Northeast China,(3)Shanghai→Korean Peninsula→Northeast China.During the overwintering period,some individuals tracked from Shanghai flew to Zhejiang Province,Jiangsu Province,and Jiangxi Province.Part of the individuals tracked in Shanghai flew between Pudong Dongtan,Chongming Dongtan,Jiuduansha and Hengsha Island.Finally,no migration behavior was observed in individuals of A.zonorhyncha monitored in Shanghai about two years.2 The results of GPS biological tracker showed that the main landscape types of A.zonorhyncha and A.platyrhynchos in Pudong Dongtan were tidal flat,farmland and inland water.Using fixed kernel estimator(FKE),we compared the percentage of available resources(POA)and the percentage of actual utilization(POU)of the two ducks in different landscape type.The results of wilcoxon signed rank test showed that the POA of A.zonorhyncha to the tidal flat was significantly higher than that of POU,there was no significant difference in the two utilization percentages of farmland and inland water.There were significant differences in the building of A.zonorhyncha only in the 95%and 75%activities.A.platyrhynchos shows significant differences only in POA and POU of building.3 Interspecific comparisons of POA,POU and POS(Percentage of selection)between two wild duck species.Mann-Whitney U test showed that the POA and POU of A.zonorhyncha in tidal flat were significantly lower than A.platyrhynchos.Only in part of the range,the POS of A.zonorhyncha was significantly lower than A.platyrhynchos.There were no significant differences in POA,POU and POS between two wild duck species in farmland and inland water.A.zonorhyncha has significantly higher POS for buildings and roads than A.platyrhynchos.The multivariate linear regression model and the generalized additive models showed that the farmland area had a significant positive effect on the GPS site distribution of the two duck species.Tidal flat area and distance to the dyke had a significant negative impact on the distribution of GPS sites in two duck species.4 From December 2020 to April 2021,the farmland and tidal flat of Pudong Dongtan were investigated by infrared camera and observed by telescope.In farmland,a total of 31 infrared cameras successfully recorded data,and 6789 valid photos were recorded.The total effective monitoring day was 1214,and the overall camera shooting rate was 5.59.A total of 62 species,14 families,5 orders of birds were recorded.In addition to moving behavior,there were significant differences in day and night of each behavior for A.zonorhyncha.During the daytime,the resting behavior of A.zonorhyncha was significantly higher than other behaviors.At night,A.zonorhyncha mainly rest and foraging.The A.platyrhynchos only had significant difference in foraging behavior,while other behaviors had no significant difference,but foraging and rest behaviors were significantly higher than other behaviors.A total of 28 species of wild birds belonging to 4 orders,6 families were investigated in tidal flat.In daytime(9:00-16:00),A.zonorhyncha(80.78%±3.86%)and A.platyrhynchos(77.46%±5.79%)mainly rest.In addition,there was no significant behavior difference between the two duck species.5 In 2018 and 2020,there were 78 and 134 poultry breeding sites in the study area,respectively.The data showed that most of the poultry in the area were bred in rivers near houses.The risk map of avian influenza virus transmission in Pudong Dongtan showed that the area of AIV transmission risk in A.zonorhyncha and A.platyrhynchos were 336.59 km~2 and 293.33 km~2,respectively.The highest transmission risk values of two duck species were 1.310‰and 2.431‰,respectively.From the relative position of poultry breeding sites and risk areas,no poultry breeding sites are located in the middle and high-risk areas in Pudong Dongtan.In conclusion,tidal flats,farmland,and inland water were the main wintering habitats of A.zonorhyncha and A.platyrhynchos in Pudong Dongtan.The two duck species mainly utilize the tidal flat by resting behavior in the daytime and utilize the farmland by resting and foraging behavior at night.The transmission risk areas of the two duck species should be included in the local avian influenza prevention and control scope,and the farmland in the risk area is the key area of avian influenza prevention and control in this region.This paper explored the rules of ducks wintering land utilization,combined with the needs of avian influenza prevention and control,to provide scientific suggestions for the protection of local duck species. |
PDF Full Text Request