| The Twite belongs to the order of Passeriformes, and the Genus of the Carduelis birds with small body size, it is also a typical mountains spcies, minly distributed between 2500-5000 meters above sea level, and has seasonally vertical migration habit in many part of the world. The Twite mainly distributed in north-west Europe and southwest Asia in global leval. The Twites are mainly distributed in Qinghai province, Tibetan autonomous region, Sichuan province and Sinkiang in China. In recent decades, some European contry has done detail research on population size and distribution of the Twite, and shown that both population size and distribution range has a downward trend, so the United kingdom, the United States and some other countries have already listed the species in the red book of endangered birds. So far studies of Twites in china still limited on the breeding ecology and the basic aspects of behavioral ecology, although there is no detailed studies in China on population size and distribution range of the Twite, the Chinese states also has listed the species in the state protects the beneficial or have important economic and scientific research value of terrestrial wildlife list by the state forestry administration in 1st of August, 2000.During January to march,in 2015, the author made a preliminary study of winter habitat selection in Lhasa valley of Twites C. F.rufostrigata. As total, 33 samples were selected from 7 different habitats, only Alpine meadow(GL) and Alpine brushes(BL) habitat could not find. The results of Tukey HSD test shows that number of Twites were only significantly different between urban area and wetland, where number of birds in wetland was much more than in the urban area. The stepwise regression analysis results shows that, coverage of herb, herb height, altitude and the distance from samplings sites to road were the environmental factors which influencing the habitat selection of Twites in the study area. Compassion analysis and PCA result showed that the environmental factors which influences habitats selection of Twites were Altitude, coverage of herb, herb height, distance from sampling sites to road and air temperature, this situation was almost as same as the result of Tukey HSD-test. According to observations on wintering activity patterns and roosting sites in the urban area of Lhasa, Twites were living in groups during the day time, about 19:30 in the afternoon most of individuals back to their roosting-site, and ended all activities of the day and then at around 8:00 in the next day morning fly away from the roosting-site. The Twite prefer to roosting in high cedrus, and usually about 120 individuals roosting in a single cedrus, and Twites like to living with Prunella fulvescens and Prunella rubeculoides.During late March to end of June in 2015, the author made a detail rearch on Twite’s nest site selection and breeding ecology, and the urban area of Lhasa was selected for major research site, we found 32 nests in total. We found that 93.75% Twite’s nest were constracted on different species of tree, which 65.6% of their nests were placed on the Cedrus, Platycladus orientalis take up 12.5%, Picea crassifolia hold 12.5%, Salixbabylonica account for 3.1%, the others 6.25% of the nests were builted on Prunus cerasifera. Therefore, Twites significantly prefer to place nests on the Cedrus(X2 = 9.080, P = 9.080), and it also had the highset of electivity index(0.44), followed by Platycladus orientalis, Picea crassifolia, Prunus cerasifera(0.32); this species has avoided species of trees Salix babylonica,Salix cheilophila,Sophora japonica,Populus alba,Pyrus sorotina,Ulmus pumila,Sabina chinensis(except the Salix babylonica as electivity index is-0.78, others are all-1) to be nest sites. Twites’ s nest height was 7.72 ±1.21 cm, depth was 3.76 ± 0.78 cm, inner diameter was 4.86 ±0.87 cm, outer diameter was 9.05 ± 1.60 cm, nest dry weight of 19.33 ±6.73 g. Twites prefer to place their nest at the junction of trunk and branch on the nesting trees, and 40.6% of nests were derectwed to the south, 28.1% of nests were located at the east sites of nesting trees. The t- test was used to check differences of environmental factors between nesting sites and the control groups, found that canopy cover of nesting- tree and woody plants coverage had significant differences(the experimental group is higher than control group), there was no obvious different with other environmental factors,. Finally, carried out the principal component analysis with 11 environmental factors, the results showed that nest tree height, canopy cover, diameter at breast height, distance to trunk, distance to water, distance to road, herb coverage and nest direction were influential factors for nesting site selection.Twites enter to the breeding season start at the end of March in Lhasa urban area, it’s the earliest report so far. Breeding behavior only ocour once in each breeding season, nest building period was lasted for 7.38±0.51 days, the average frequency of transportation of nest metarial was 46 times/day; the behavior of nest building mainly concentrated between 9:00-13:00; egg laying period was 4.1±0.57 days, laying time was in the morning between 8:00 to 9:30, one egg was layed perday, average clutch size was 4.1eggs(SD= 0.57, range 3-5), the clutch size decrease with egg lying date, if eggs lost during the period of laying, they did not lay any supplemental eggs at all. The female start to incubate after the fisrt egg was laied, duration of incubation was increasing with increasing rate of the cluch size, average egg weight was 1.43± 0.21 g, major egg axis was 17.30 ±0.51 cm, minor egg axis was 12.28 ±0.47 cm, the Duration of incubation period was 13.88±0.99 days, frequency of brooding female leaving nest for feeding was 6.00 ±2.69 times/day; and male courtship feeding frequency was 9.11±2.26 times per day; The total duration of incubation during the day time(8:00-20:00) was 11.08 ± 0.58 h, the average period of feeding nestling was 11.28±0.95 days, the average weight of chicks at the age of zero was 1.38 ±0.37g; Reproductive failure rate as high as 53.13%, of which the nest stage failure rate is 31.25%, egg stage failure rate was 9.38%, the young period failure rate was 12.50%. |
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