同域分布马鹿与中华斑羚的冬夏季食物构成比较

Differences in Winter and Summer Diet Composition between Sympatric Red Deer and Chinese Goral

同域分布的有蹄类动物面临食物资源竞争,而食物又是影响野生动物生存的关键因子之一,研究不同种类动物的食物构成可以反映其对栖息地条件的适应程度。本研究通过粪便显微分析法,对内蒙古赛罕乌拉国家级自然保护区马鹿(Cervus elaphus)和中华斑羚(Naemorhedus griseus)的冬、夏季食物构成进行比较分析。结果显示,马鹿在夏季取食22科48种植物,中华斑羚取食15科31种植物;在冬季,马鹿取食17科32种植物,中华斑羚取食13科23种植物。Pianka重叠指数显示,夏季时马鹿与中华斑羚食物重叠度为85.4%,冬季重叠度为77.6%。使用Levins指数计算,夏季时马鹿与中华斑羚的营养生态位分别是13.71和5.34,冬季时分别是11.08和4.02。在同一季节,马鹿取食植物的丰富度和均匀度均大于中华斑羚。本研究结果表明,马鹿与中华斑羚的食物选择对季节性食物资源变化具有适应性,但马鹿对环境的适应性高于中华斑羚;鉴于马鹿的分布范围广、种群数量多,建议在对物种与栖息地的保护中侧重于中华斑羚。

[Objectives]The availability of food resources is a key limiting factor of wildlife survival.Therefore,determining the competition status of sympatric species in relation to such resources is important for understanding their ecology and conservation requirements.The aim of this study was to analyze the competition status of sympatric Red Deer(Cervus elaphus)and Chinese Goral(Naemorhedus griseus)regarding diet composition and adaptability in Saihanwula Nature Reserve.[Methods]Using microscopic analysis of fresh fecal samples collected from August 2019 to July 2020(Fig.1),trophic niche width and overlap were calculated based on the diet composition of Red Deer and Chinese Goral.Significance tests for inter-seasonal and inter-species diet composition were carried out using a non-parametric Kruskal-Wallis model.[Results]The results showed that Red Deer fed on 48 plant species from 22 families in summer,and Chinese Goral fed on 31 plant species from 15 families.In winter,Red Deer fed on 32 plant species from 17 families,and Chinese Goral fed on 23 plant species from 13 families(Table 1).The frequency of each diet item varied significantly by season(Red Deer:χ^(2)=46.6,df=5,P<0.01;Chinese Goral:χ^(2)=17.4,df=3,P<0.01)(Fig.2),and the trophic niche widths were greater for Red Deer than Chinese Goral in summer(Levin’s index of 13.71 and 5.34,respectively)and winter(Levin’s index of 11.08 and 4.02,respectively).The two species had a large dietary overlap(85.4% in summer,77.6% in winter),and the trophic niche and diet diversity indices in summer were all significantly higher than those in winter(Table 2).[Conclusion]The results indicate that Red Deer are more adaptable to seasonal changes in food resources,although Chinese Goral may also adjust their feeding strategies.Given the wide distribution range and large population size of Red Deer,it is recommended that more conservation efforts be focused on Chinese Goral and their habitats.