Spatio-temporal Habitat Selection Of Wild Crested Ibis (nipponia Nippon) And Modeling Of Reintroduction Sites

In-situ conservation and reintroduction are important tools for conservation and recovery of endangered wildlife,which can help to maintain the reproduction and evolution of organisms in ecosystem.The primary form of in-situ conservation is habitat protection and management,which requires a scientific knowledge of habitat selection of wildlife.A sound assessment of habitat suitability is key to successful reintroduction of species.The wild population of Crested Ibis(Nipponia nippon)has been expanding in recent years,the distribution hence covered different habitats.It is necessary to accurately understand the habitat selection for better In-situ conservation.Presently there is only one wild population of Crested Ibis in the world,and the survival rate of existing reintroduced populations is relatively low,new and suitable reintroductions are hence needed to promote the recovery of this species.In this study,based on field surveys,satellite tracking and 3S technology from 2015 to 2020,the habitat(breeding,feeding and roosting)selections of Crested Ibis at multiple spatial and temporal scales were investigated comprehensively for the first time.Besides,a reasonable species distribution model based on the occurrence data of wild population and environmental variables was constructed to predict the potential distribution of Crested Ibis in China,and further identify the potential reintroduction areas by combining dispersing analysis and habitat assemble.The main results are as follows:1.In mountain areas the masson pines Pinus massoniana were most frequently used(64.6%,n =48),while in plains the elms Ulmus pumila(44.9%,n = 69)and aspens Populus davidiana(40.6%)were used frequently due to the difference in abundance.The ibises selected tall nesting trees with larger diameter at breast height(DBH)and preferred nesting higher.The ibises also preferred nesting close to tree trunk.In mountain areas,slope and distance to path had positive effects on nesting occurrence,and understory coverage was avoided by nesting ibises,while these variables had little impact in plains.Areas around nest sites were rich of food resources.2.During the wintering period,Crested Ibis selected wide feeding sites with large percentage of water surface and far from woodland;during the breeding period,Crested Ibis selected wide feeding sites with shallow water and far from roads;during the wandering period,Crested Ibis selected feeding sites with large percentage of water surface,shallow water and far from woodland;water factors(e.g.rivers,reservoirs,ponds)are important in feeding-site selection of Crested Ibis in all three periods.3.The main roosting-tree species used in mountains and plains were consistent.During the wintering period,the ibises selected roosting sites with trees that were larger in coverage and DBH,and the surrounding terrain was flat;during the breeding period,the ibises selected roosting sites with lower slope,larger tree cover but smaller roosting tree cover,and the surrounding paddy fields was rich.4.Results from species distribution model showed that there are three potential suitable areas for Crested Ibis reintroduction,located in the eastern Qinling and Daba Mountains,the Dabie Mountains,and the southern Anhui Mountains,respectively.The corresponding suitable release sites are located in the areas centered in Nanzhang County,Yuexi County and Jixi County,respectively.Our results revealed that tall trees with suitable nesting places are the key in driving nest-site selection of this ibis,particularly in lower altitude plains.We suggest that higher trees like relatively tall elms and aspens in plains.To reduce human disturbance to breeding ibises,the public education should be strengthened to raise the local consciousness of wildlife protection.As the distribution of Crested Ibis is still expanding,further efforts to establish new monitoring stations in recently expanded areas should be planned and implemented.Factors associated with water(i.e.rivers,reservoirs,and ponds)have an important influence on the year-round feeding-site selection and the roosting-site selection of Crested Ibis,riverbank wetlands such as the Han River and its tributaries should be preserved.For future reintroduction,priority should be given to the areas centered in Nanzhang County,Yuexi County and Jixi County,respectively.