Habitat Selection Of Snow Partridge (Lerwa Lerwa) And Its Habitat Comparion With Tibetan Snowcock (Tetraogallus Tibetanus) On The Qinghai-Tibetan Plateau

Habitat selection carrying with it a connotation of understanding complex behavior and life history,understanding habitat use is important for species protection and conservation,particularly for species such as Snow Partridge(Lerwa lerwa),one of the little known birds distributed along the Himalayas with high altitude and harsh climate.Besides,global warming has been responsible for partial melting of glaciers on the Qinghai-Tibetan Plateau,in particular,more serious at the edge of the Plateau than those on the Plateau itself.Since the Snow Partridge lives at elevations close to glaciers and the snow line,its habitat and therefore,its survival is likely to be affected.Tibetan Snowcock(Tetraoganllus tibetanus),with many similarities of habitat with Snow Partridge in a certain range,was also available and of interest in exploring this phenomenon,which would contribute to reveal the reasons of the habitat difference between the two plateau endemic pheasants.We conducted field surveys at Balangshan in August 2013,at Shangri in January 2015 and Yulong Mountain in August 2016 on the Qinghai-Tibetan Plateau of west central China.We used models of Random forests to determine the micro-habitat variables that Snow Partridges might select based on 18 micro habitat variables and a maximum entropy algorithm(MaxEnt ver.3.3.3.e)to predict the distribution for three counties(Wenchuan,Xiaojin and Baoxing,Sichuan Province)adjacent to our main study site,with a total area of 12800 km2.We compared the distribution between Snow Partridge and Tibetan Snowcock from meso-scale of the three counties and macro-scale of the whole distribution based on MaxEnt.We tried to analyse history distribution changes of Lerwa lerwa by comparing suitable distributions of three timeframes of current period,LIG and LGM.We found a total of 15 flocks of Snow Partridge in the study area,on pyramidal peaks,aretes and steep rock slopes above 4390 m.The species was associated with habitats of the top of high cliffs or flatter terrain closed to high cliffs,less steep slope and high altitude.Terrain factors were the main factor affected the partridge' micro-habitat selection while vegetation was a more important factor at meso-scale,with altitude being consequential at both scales.Only approximately 6.64%of study areas had the features that might provide the suitable habitat for the species.At meso-seale,the suitable habitat of Tibetan Snowcock was larger than the Snow Partridge's and the overlap area of them about 761.57 km2 occupied 89.97%of Snow Partridge's and 79.63%of Tibetan Snowcock's habitat respectively,which indicated that habitat range of Snow Partridge was similar with Tibetan Snowcock's,however,with the factor of distance to ridge been not important for Tibetan Snowcock while it is of significance for Snow Partridge.At macro-scale,they clearly occupied different distributions such that Tibetan Snowcock occurred on the Qinghai-Tibetan Plateau while Snow Partridge confined the south margin of the Plateau.With a higher ratio of 72.33%of Snow Partridge's by their overlap range,it was 4.7%that the overlap range occupied the whole distributions of Tibetan Snowcock.With larger body size than Snow Partridge,Tibetan snowcock might be more powerful to inhabit larger area than the Partridge.That Tibetan snowcock distributed on a broad area could be because Tibetan snowcock adapt to wider climate condition,while snow partridge restricted on narrow humid climate area,which appeared in high altitude and at the edge of Tibetan plateau.At three timeframes of current period,LIG and LGM,Snow Partridge distributed all along on the southern fringe of Qinghai-Tibetan Plateau.The birds might be with three history populations in period of LIG.We suggest that the abatement of human-induced activities such as grazing and herb gathering should be taken into account in developing long-term protection strategies for Snow Partridge and other wildlife species in the area,particularly with the concerns that global warming may further reduce the availability of suitable habitat for these species associated with high altitude and cool climate conditions.