Breeding Ecology Of The Red-winged Laughingthrush At Laojunshan Nature Reserve,Sichuan

Red-winged Laughingthrush(Garrulax formosus)is a rare species of babbler,which is mainly distributed in southwest of China,and the breeding data of this species are very scarce.It is helpful to deepen our understanding of the species and strengthen the population protection and management of Red-winged Laughingthrush by carrying out the study of babbler propagation ecology.From 2014 to 2016,this paper mainly studied the breeding ecology of Red-winged Laughingthrush in Laojunshan National Nature Reserve,Sichuan Province,and discussed the coexistence of Red-winged Laughingthrush and Red-billed Leiothrix reproduction.The main results were as follows:(1)In May 2016,the breeding population density of Red-winged Laughingthrush was investigated in Laojunshan National Nature Reserve of Sichuan Province by sampling line method.A total of 20 lines were set up,each with a length of 1 km and a total length of 20 km.The sample line covered the main vegetation types and most of the altitude in the study area.We detected this species mainly by its characteristic songs uttered by males.The results showed that the Red-winged Laughingthrush mainly distributed in the primary forest and secondary forest,and was more concentrated in the primitive forest.The results of fixed-distance line transects and distance sampling techniques were 11.806/km~2 and 14.733/km~2(95%CI:11.727?18.511;CV:0.115),respectively.The average population density of Red-winged Laughingthrush in primitive forest was 25.310/km~2(95%CI:19.539?32.786;CV:0.130).(2)In the breeding season from 2014 to 2016,the reproductive ecology of Red-winged Laughingthrush was studied in Laojunshan National Nature Reserve.Observation showed that the breeding period of Red-winged Laughingthrush was from late April to mid-September in Laojunshan National Nature Reserve of Sichuan Province lasted.During the three breeding seasons,we found a total of 25 nests.Red-winged Laughingthrush preferred to build nests in dense habitats of bamboo forests between elevations of 1 507 m and 1 944 m.The vegetation around the nests was mainly composed of the bamboos and lianes,with few large trees.The nests were cup-shaped,with a mean height of 2.75�0.2 cm(n=29)above the ground.The outer diameter of nest was 17.8�0.7 cm(n=10),the inner diameter of nest was9.4�0.3 cm(n=10),the depth of nest was 7.4�0.2 cm(n=10),and the height of nest was 11.6�0.4 cm(n=10).The nesting plant was mainly C.szechuanensis.The female laid an egg every morning.Mean clutch size was 2.28�0.09 eggs(n=25),The length diameter of egg was 29.7�1.6 mm(n=6)and the short diameter was 21.3�1.6 mm(n=6).Incubation started after the last egg was laid.The incubation period was about 14?15 days,and the hatching success rate was about 60.4%.The nestling period was 14 days,and the fledging rate was about 53.1%.Nest predation was the primary factor causing the breeding failure of Red-winged Laughingthrush.(3)The results of nest-site selection showed that Red-winged Laughingthrush tended to use the vegetation type of bamboo,and selected less cover of trees,higher Bamboo,higher cover of bamboo.The results of logistic regression analysis showed that tree coverage might be the key ecological factor affecting the selection of nest sites of Red-winged Laughingthrush.The prediction accuracy of the selection of nest sites of Red-winged Laughingthrush was 74.1%by the regression model composed of tree cover.