Habitat Evaluation For Reintroduced Crested Ibis (Nipponia Nippon) In Dongzhai National Nature Reserve, Based On Maximum Entropy Model

The Crested Ibis(Nipponia nippon)used to be widely distributed in the eastern Asia,but now it is global endangered due to habitat loss and destruction,and is a first-rate protected wild animal in China.Since the last wild population of Crested Ibis was rediscovered in Yangxian County in 1981,after more than 30 years of in-situ and ex-situ conservation studies,the population has increased to more than 2,000.The wild population exceeds 1,500 now,but most of the wild populations are still distributed in Yangxian County and surrounding areas in the Qinling Mountain.Dongzhai National Nature Reserve in Henan Province,is China's first re-introduced site for Crested Ibis outside Shaanxi Province.The reserve received a total of 17 crested ibis in 2007,and the captive breeding population increased to 132 birds by February 2013,so the reserve began to acclimation and release Crested Ibis in 2013.Habitat evaluation and prediction are the basis for effective protection and management of endangered species.It is of great significance to carry out the evaluation of habitat suitability to Dongzhai's reintroduction of Crested Ibis.Based on the 3S platform,this study used ENVI5.1 software to interpret the landsat-8 remote sensing images in 2013,and divided the land surface land use types into forestland,farmland,wetland and residential area;The elevation,slope and aspect data of the research area were obtained through the ASTER GDEMV2 geographic elevation data;and road data were obtained from the professional website.All variables were processed through Arc Gis10.3 software,filtered through Max Ent model and correlation test,and finally selected six environmental factors including elevation,slope,aspect,distance to forest land,distance to road,and distance to wetland.Combined with the presence data of the 23 reintroduction Crested Ibis by field monitored from 2013-2015,then the maximum entropy model(Max Ent)was used to evaluate the suitability of habitats in the Dongzhai Nature Reserve and its surroundings area.The prediction results of the model are proved to have higher accuracy through the ROC curve test,and the Crested Ibis habitat suitability distribution map is finally generated.The main results are as follows:1.The model for crested ibis produced a training AUC value of 0.923 ± 0.006 and a testing AUC value of 0.856 ± 0.032,indicating that the Max Ent model had high prediction accuracy.2.The most important environmental factors affecting the distribution of Crested Ibis are elevation,distance from woodland,distance from road,followed by slope,aspect and distance from wetland.The study showed that the ibis had a good adaptability to low altitude,and also reflected that the crested ibis had a certain dependence on human agricultural activities,but also kept a certain distance from the human accumulation area.3.Habitat suitability decreases with slope and distance from the road.The altitude of 90-100 m is the most suitable elevation of Crested Ibis.Within 200 m away from the wetland,the suitability increases with the increase of distance,and the fitness for this value increases with distance.However,in the clockwise direction from east,the habitat suitability of Crested Ibis gradually decreased.4.The habitat quality of the crested ibis is pretty good,but there is few distributing in the Dongzhai reserve(143.12 km2),and mainly distributed in the northwest and central of the protected areas,and it is unable to meet the growing requirements of breeding habitats.In the study area,the area and proportion of suitable habitats in Luoshan County is the largest(517.18 km2),followed by Xinyang City(465.61 km2),Dawu County(222.94 km2)and Guangshan County(180.17 km2).Crested Ibis is likely to gradually spread to the three directions of Xinyang,Dawu county and Guangshan County in the future.In this study,the potential wild distribution of reintroduced crested ibises in Dongzhai was introduced,and the factors affecting the habitat suitability were discussed.The habitat suitability distribution map was drawn to provide reference for the monitoring,protection and management of crested ibis.The work has a certain reference value for the re-introduction of crested ibis in other regions.