Study On Nest Selection Strategy Of Spotted Dove Spilopelia Chinensis In Urbanization Habitat

Urbanization is a process of rapid habitat change induced by anthropogenic activity,which could accelerate the phenotypic differentiation of animals and affect their reproduction success.The rapid evolutionary adaptation mechanism of animals caused by severe human interference has become one of the hot spots of contemporary ecological theory research.Under the pressure of urban habitat selection,avian must rearrange and optimize their reproductive effort,and adjust their reproductive strategies to adapt to the new habitats.Understanding the mechanism of rapid evolution and adaptation of birds had significant implication to construct ecological civilization city of human-bird harmony.In this study,we systematically investigated and monitored the breeding nests of spotted dove Spilopelia chinensis in Qianhu area of Nanchang City in breeding seasons of 2019 and 2020.Combining the quantitative analyses of environmental factor and breeding parameter in breeding season,we discussed urban bird nest-site selection strategy,breeding strategy and trade-off mechanism of nest reuse,and the main results and conclusions are as follows:1.A total of 232 nests of spotted dove were detected in our surveys,one of which was in the secondary forest,and the remaining 231 nests located in the artificial greenbelt.There were 22 nested-tree species utilized.Spotted dove prefered to nest in sequence on Cinnamomum camphora(31.90%),Elaeocarpus decipiens(20.26%)and Osmanthus fragrans(19.83%).The results of principal component analysis(PCA)showed that this bird preferred to nest in the trees with higher height,better concealability and less disturbance.Logistic regression analysis results identified the best nest site selection model for affecting the breeding success(AICc=300.640,(?)AICc=0.000,?_i=0.572),which suggested the main factors including nest height,crown diameter,canopy closure and distance from road.The selection pressure of urban birds mainly come from nest predation and human disturbance,and nest location selection was the combining result from pressures of nest predation and human disturbance.Artificial greenbelt can provide abundant food resources and good nesting environment for urban birds breeding,but it will also bring adverse effects.Although there is less predation pressure and human disturbance in the artificial greenbelt than in the building and secondary forest habitats,compared with the natural habitat,the new nest predation and greater urban human disturbance bring greater energy consumption to birds.Generally,a series of countermeasures for urban birds to cope with urban pressure in nest location selection can make them survive and breed better in cities.2.Among 232 monitored nests,ta total of 84(36.21%)old nests were reused,including 66(78.57%)old nests of the same species and 18(21.43%)old nests of the different species.The frequency of using the same species'old nest was significantly higher than that of using the different species'(?~2=54.857,df=l,P<0.001)at the0.001 level.The tree height(z=2.077,df=230,P=0.038)and nest height(z=2.434,df=230,P=0.038)of used old nests were significantly higher than those of unused old nests,while the canopy density of used old nests was significantly lower than that of unused old nests(z=-2.121,df=230,P=0.034).The reproductive success rate of reused old nests was significantly higher than that of unused old nests(?~2=4.762,df=l,P=0.038).The location(stem class)of reused old nests was significantly lower than that of unused old nests(z=-2.672,df=230,P=0.008)at the 0.01 level.Branches of reused old nests were significantly higher than that of unused old nests(z=2.166,df=230,P=0.030).The volume of thick branches(z=-2.059,df=71,P=0.016)and the mean diameter of thin branches(t=-2.186,df=71,P=0.032)of old nests used were significantly lower than those of unused old nests,respectively.The utilization of old nests by urban birds is the result of comprehensive measurement of risks and benefits under nest predation,natural disaster and human disturbance pressure.This bird preferred to use old nests with high nesting position,good safety and stability.Old nest utilization is an optimized nest site selection strategy.High-quality old nest for reusing birds mean the low nest predation,strong resistance to natural disasters and low human disturbance,which will promote to high reproductive success of birds.