藏雪鸡(Tetraogallus tibetanus)春夏季食性

Spring and summer diet composition of Tibetan snowcocks

藏雪鸡(Tetraogallus tibetanus)生活在青藏高原及其毗邻地区,是国家二级保护动物。2016年5—8月,在青海省尖扎县,采集藏雪鸡新鲜粪便及可能食用的植物,采用粪便显微分析法研究了藏雪鸡食性。结果表明:藏雪鸡能以各种植物器官为食,叶片是其食用的主要器官,茎次之,再次是花和果(种子),根极少;藏雪鸡所食植物器官比例有明显季节变化,叶片的比例逐月下降,花的比例在7月显著增加,而果(种子)比例在8月陡增至28%;藏雪鸡能以生境中24科72种草本植物中的19科49种为食,还取食苔藓和地衣;禾本科和菊科植物是其主要食物,占食物总量的42%;草地早熟禾(Poa pratensis)(22.35%)是主要食物种,蒲公英(Taraxacum mongolicum)等20种植物是其常见食物种;藏雪鸡所食植物种类比例季节变化明显,如草地早熟禾比例5—7月稳定在20%左右,但8月上升到30.20%,而蒲公英比例5—8月持续增加;藏雪鸡所食植物种类数稳定在35~36种,仅7月稍多(41种);不同月份的食物成分相似性较高(>73%),食物的Shannon多样性指数和Pielou均匀度指数相似,但8月食物生态位宽度指数明显低于其他月份。综上,藏雪鸡是广食性鸟类,且食性有明显的季节变化。本研究结果可为藏雪鸡救护和迁地保护时人工饲料配方的设计提供依据。

Tibetan snowcock(Tetraogallus tibetanus)is a second-class national protected animal in China,inhabiting in the alpine bare rocks and meadows of Qinghai-Tibetan Plateau and the adjacent areas.Little information on the diet of Tibetan snowcocks is available.We collected all plant species that may be eaten by the birds and the fresh feces of Tibetan snowcocks in the foraging habitat on the mountain in Luowa Village,Jianzha County,Qinghai Province from May to August in 2016.The diet was determined by microscopic fecal analysis.The proportion of each identified plant species was calculated.The results showed that all plant organs can be eaten by the birds.Leaves are preferred,followed by stems,flowers,seeds,and roots were rarely eaten.The proportion of plant organs exhibited seasonal variation.The proportion of leaves gradually decreased,that of stems changed little,that of flowers increased obviously in July,and that of fruits(seeds)increased sharply in August(28%).A total of 72 plant species from 24 families were found in snowcocks’habitat,with Pteridophyta,Bryophyta,and Lichenes being also eaten.Most of the plants(49 species categorized into 19 families)as well as Bryophyta and Lichenes were the food source.Gramineae and Compositae were the main food source,accounting for more than 42%of its diet.Poa pratensis(22.35%)was the main food species of snowcocks,and 20 species including Taraxacum mongolicum were the common food.From May to August,the variation of the proportion of plant species eaten by the birds was obvious.The proportion of Poa pratensis was stabilized at about 20%from May to July,and rose to 30.20%in August,while the proportion of Taraxacum mongolicum generally increased from May to August.The number of plant species eaten by Tibetan snowcocks was relatively stable(35-36 species)from May to August and slightly higher(41 species)in July.Food composition of Tibetan snowcocks in different months showed higher similarity(>73%).Shannon diversity index and Pielou evenness index were similar from May to August,but the food niche breadth in August was significantly lower than that in other months.In conclusion,the dietary of Tibetan snowcocks is wide and with a distinct seasonal variation.Our results can provide a basis for the design of artificial feed for a rescue and ex-situ protection of Tibetan snowcocks.