| Food is the material basis for the survival of birds.Studying the feeding habits of birds could be helpful to accurately understand the relationship between birds and their habitats,and will be of guide significance on the research of bird ecology and the protection of birds.However,in recent years,the acceleration of urbanization has led to a serious threat to the survival habitats of birds.In urban habitat,as the main food of phytophagous birds,plant community resource is a key factor affecting the behavior,habitat selection and reproductive success of birds.Therefore,the representative avian species spotted dove(Spilopelia chinensis)in Chinese cities was selected as the research object in this paper.Based on DNA metabarcoding technology and environmental plant quadrat investigation,this paper studied the variation of feeding characteristics for spotted dove with seasonal vegetation changes,and explained the plant species relationship between urban habitat the environment.Firstly,the territory of the spotted dove in urban habitat was confirmed by satellite tracker,and its daily foraging rhythm was monitored by camera trap.We also constructed 118 environmental plant gene banks,including 44 obtained by first-generation sequencing and 74 downloaded from Gen Bank.We then investigated 962foraging sites of spotted dove by transect method,and collected 251 feces of spotted dove in the study area for high-throughput sequencing to analyze food habit.Finally,the methods of data analyses such as metabarcoding technology,correlation analysis,independent sample T-test,multiple comparison method and generalized linear model were used for further analyses.The main results of this study are as follows:(1)This study effectively explored the feeding habits of spotted dove through the combination of satellite tracker positioning,camera trap monitoring,crop detection and metabarcoding technology.The field range of spotted dove was determined by satellite trackers.Its maximum active area was 91145.80 m~2 and the minimum active area was15265.30 m~2.The daily foraging activity rhythm of spotted dove was monitored by camera traps.The results showed that the foraging peak of spotted dove was 6:00-9:00am and 17:00-19:00 pm.Metabarcoding technology effectively explored the feeding habits.Through the correlation analysis between the proportion of each plant in the crop of the spotted dove and the relative dominance of fecal plants,it was concluded that there was a strongly significant correlation between the proportion of the crop of the spotted dove and the relative dominance of fecal plants at the 0.001 level(r=0.633,p<0.001).This provided a strong support and basis for our design of experimental schemes such as investigation scope,quadrat size,behavior investigation and sampling time.(2)Birds tended to forage in environments with little human interference to reduce the consumption of early warning energy in urban habitats.The best generalized Poisson regression model showed that the spotted dove tended to forage in habitats far away from roads and high grass height.The most important ecological factors affecting the selection of foraging habitat types of spotted dove was selected by logistic regression model,whose key factors were foraging frequency(β=-4.195,z=-5.144,p<0.001)and distance from the road(β=-0.022,z=-2.136,p=0.033).The results also showed that the foraging frequency(0.42±0.23)of the spotted dove foraging on the grassland was significantly higher than that on the cement pavement at the 0.001level(0.30±0.16,t=4.998,df=960,p<0.001).The distance from the road of the spotted dove foraging on the grassland(14.44±16.22 m)was also significantly higher than that on the cement pavement at the 0.05 level(10.35±11.37 m,t=2.271,df=960,p=0.023).(3)Food resources will mainly decide the foraging niche of birds.The change of food resources in urban habitat will change the foraging niche of the spotted dove.The spotted dove gradually changes from feeding on crop seeds to feeding on plant seeds in urban green belt.In this study,100 different plant groups were identified in the analysis of one-year feeding habits of spotted dove,including Cinnamomum camphora,Kummerowia striata,Poa annua and other greening belt plants species The widest foraging niche(B=8.48)was detected in spring with the highest plant diversity(~′=1.74),while the narrowest niche(B=2.56)was found in the winter with the lowest plant diversity(~′=0.58).The foraging niche width of spotted dove reached the narrowest(B=2.56).The overlap index of foraging niche of spotted dove in the four seasons was some(0.24-0.58),which indicated a good differentiation in the four seasonal feeding niches for spotted dove.(4)Food richness will affect the food preference of spotted dove.The stronger selectivity of spotted dove to food was found in the season with more abundant food.In this study,the spotted dove indicated an obvious seasonal preference for the foraging of herbs.In spring and summer with high plant diversity,more food resources led to stronger food preference for spotted dove,whereas the spotted dove changed its foraging strategy in autumn and winter with low plant diversity,and forage basic food resource such as Kummerowia striata for energy supplement. |
