Duan Y.,Northeast Forestry University |
Tian X.,Northeast Forestry University |
Zhu S.,Yellow River Estuary National Nature Reserve |
Ding P.,Chinese Academy of Sciences |
And 2 more authors.
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2011
25 Oriental white stork breeding nests that have been found and positioned with a global positioning system (GPS) from March to May 2009 in the Yellow River Estuary nature reserve. To nest-site as the center, Setting a 10m × 10m square quadrat in which center, and set up a 1m × 1m square sample side at the four corners of each quadrat. Reference of our predecessors of other people's research methods and the actual situation, determination of the 16 ecological factors selective: vegetation type, nest position height, water depth in quadrat proportion of water in quadrat vegetation height vegetation density vegetation coverage the distance to water & water depthn the distance to the reed marsh the distance to the road the distance to the tourist area the distance to the mild disturbance the distance to grassland the distance to forests the distance to farmland. In order to ensure the randomness of quadrats the study area will be divided into 50 equal or similar areas, so that the quadrat must be covered the whole of the study area. If the Oriental White Stork nests had still living within the quadrats, which quadrad has to remove. A total of 25 random quadrats were filtrated. Caurse of here were not tall trees in the study area, so the control samples were poles. Because the data didn't accord with normal school, 16 ecological factors were analysised relevanced with spearman. There were 9 of the absolute value of the correlation coefficient greater >0. 5. The independence and representation of the factor, selected little them nine ecological factors (distance to water distance to the road distance to the tourist area distance to the mild disturbance distance to grassland distance to forests distance to the reed marsh vegetation density vegetation coverage) to get in logistic regression. After parameters standardized, Using forward: conditional for logistic regression analysis, and finally entering the function equation are significant statisticaHy variables were; vegetation density distance to the mild disturbance distance to grassland distance to water distance to the road. The results showed that the resource selection function of Oriental white stork nest-site; logist (p) = - 0. 206 - 2. 773 X the distance to water +2. 200 X the distance to the road + 1.444 the distance to mild disturbances + 1.205 the distance to grasslands + 1. 191 vegetation density. The model indicated that Oriental white stork to choose a nest-site having relevance with a distance to water were a negative correlation, and the distance to the road, the distance to mild disturbances, the distance to grasslands, vegetation density was positively correlated. Otherwise indicated that the Oriental white stork to select areas inclined, closing to the water, far to the road, far to mild disturbance, grass distance and great vegetation density for nesting. According to the resource selection functions, the nest-site choice probability of Oriental white stork P = elogist(p), /[1 + elogist(p),]. The correct rate; 88.6% (R2 = 0. 721). Food, human disturbance and vegetation density are main factors, affect the nest-site use of Oriental white stork.
Duan Y.B.,Northeast Forestry University |
Tian X.H.,Northeast Forestry University |
Ma J.Z.,Northeast Forestry University |
Zhu S.Y.,Yellow River Estuary National Nature Reserve |
Shan K.,Yellow River Estuary National Nature Reserve
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2015
The oriental white stork (Ciconia boyciana) is one of the largest birds, with a wing span of up to two meters. Its breeding territory extends from the Amur to the Ussuri River in east Siberia, and 2500 individuals estimated still exist worldwide. According to the IUCN red list, however, the survival of this species is still in peril. Yellow River Estuary nature reserve had become their new breeding sites since 2005. From March to June in 2008 and 2009, the forage habitat use of Oriental white stork during its breeding season was studied in the Yellow River Estuary nature reserve by the methods of fixed-spot observation, GPS positioning, sampling plot investigation and stepwise discriminant analysis, by the methods of fixed-spot observation, GPS positioning, sampling plot investigation and stepwise discriminant analysis. With a forage site as the center, a 1m × 1m square quadrat was Set up, and another four square samples were installed of 5-10 miles around the first square quadrat. Based on the previous research methods and the actual situation, 14 ecological factors were determined as follows: vegetation type, vegetation height, vegetation density, vegetation coverage, sheltering class, water depth in quadrat, the distance to water, the distance to the reed marsh, the distance to the serious disturbance, the distance to the mild disturbance, the distance to grassland, the distance to forests, distance to nest and the distance to farmland. In order to ensure the randomness of quadrats the study area will be divided into 256 areas with equal or similar size, in which the quadrat must be covered. If the Oriental white stork foraged within the quadrats, this quadrat would be removed. A total of 75 foraging and 74 random plots were measured and analyzed in each site. The Oriental white stork preferred water depth of about 20cm, the reed marsh and the beach, while they avoided grassland and farmland. Comparing the used sites with the random plots, the used sites were characterized by lower vegetation height and density, lower water depth, shorter distance to water source, the reed marsh and forests, farther to the serious disturbance, and more abundance of food. Nine ecological factors which had significant difference were analyzed using Spearman's rank correlation test, and the correlation coefficients were less than 0.6. Stepwise discriminant analysis indicated that distance to the reed marsh, water depth in quadrat, distance to the serious disturbance, distance to the serious disturbance, food abundance, distance to water were critically factors to discriminate foraging sites and random plots. The overall classification model developed from five variables was successful to distinguish the used sites from random ones at probability of 95. 5%. Water, human disturbance and food are main factors which affect foraging habitat use of Oriental white stork during its breeding season. © 2015, Ecological Society of China. All rights reserved.