摘要
The East Dongting Lake National Nature Reserve in China is listed as a Ramsar Wetlands due to its global significance for migratory waterbird conservation, especially for the geese. For example, more than 90% of East Asian population of the vulnerable Lesser White-fronted Goose(Anser erythropus), and large numbers of Bean Goose(Anser fabilis) and Greater White-fronted Goose(Anser albifrons) over winter here every year from October to the next March. However, the habitats and food quality of the wintering geese have been threatened by hydrological alternation due to the operation of the Three Gorges Dam. Understanding the diets of these geese is fundamental for their conservation. We used the stable isotopic ratios of the body tissues of three predominant goose species(i.e. Ans?er erythropus, Anser fabilis and Anser albifrons) and their potential diet items(6 grass species), and applied smooth transition autoregressive(SIAR) mixing models to quantify the contribution of different food items to their diets. The results showed that the δ13C values of the blood samples were significantly different from those of feather, and the difference was consistent for the three kinds of geese. These results indicated that clear dietary shifts from their breeding place at the Arctic to the wintering place at Dongting Lake. The δ13C values of the blood samples of the geese showed there were no significant difference(ANOVA, p=0.265) suggesting that they share the same food sources at Dongting Lake. Moreover, the multiple-source mixing models(i.e. SIAR model) indicated that no single plant had a contribution greater than 35% to the diet of geese at 0.95 confident levels(0.50 and 0.95 credibility intervals of the posterior distributions range from 0.24-0.25 and 0.32-0.34, respectively). The results indicated that the geese had no preference for a particular plant. The findings suggested that the features at patch level(e.g. vegetation greenness and development stage) but not plant species might be the decisive factor in the habitat selection of the geese. Therefore,the management actions aiming to maintain habitat quality were critical for the waterbird conservation in Dongting Lake.
The East Dongting Lake National Nature Reserve in China is listed as a Ramsar Wetlands due to its global significance for migratory waterbird conservation, especially for the geese. For example, more than 90% of East Asian population of the vulnerable Lesser White-fronted Goose（Anser erythropus）, and large numbers of Bean Goose（Anser fabilis） and Greater White-fronted Goose（Anser albifrons） over winter here every year from October to the next March. However, the habitats and food quality of the wintering geese have been threatened by hydrological alternation due to the operation of the Three Gorges Dam. Understanding the diets of these geese is fundamental for their conservation. We used the stable isotopic ratios of the body tissues of three predominant goose species（i.e. Anser erythropus, Anser fabilis and Anser albifrons） and their potential diet items（6 grass species）, and applied smooth transition autoregressive（SIAR） mixing models to quantify the contribution of different food items to their diets. The results showed that the δ13C values of the blood samples were significantly different from those of feather, and the difference was consistent for the three kinds of geese. These results indicated that clear dietary shifts from their breeding place at the Arctic to the wintering place at Dongting Lake. The δ13C values of the blood samples of the geese showed there were no significant difference（ANOVA, p=0.265） suggesting that they share the same food sources at Dongting Lake. Moreover, the multiple-source mixing models（i.e. SIAR model） indicated that no single plant had a contribution greater than 35% to the diet of geese at 0.95 confident levels（0.50 and 0.95 credibility intervals of the posterior distributions range from 0.24-0.25 and 0.32-0.34, respectively）. The results indicated that the geese had no preference for a particular plant. The findings suggested that the features at patch level（e.g. vegetation greenness and development stage） but not plant species might be the decisive factor in the habitat selection of the geese. Therefore,the management actions aiming to maintain habitat quality were critical for the waterbird conservation in Dongting Lake.
出处
《湿地科学》
CSCD
北大核心
2016年第3期337-346,共10页
Wetland Science
基金
Under the auspices of the Major State Basic Research Development Program of China(2012CB417005)
the National Natural Science Foundation of China(41471072)
