关键词: 东方田鼠, 食物组成, 洞庭湖区

Abstract: The stomach content s of Yangtze voles (Microtus fortis calamorum ) , w hich were
collected in Carex f lats, rice field, hill in Matang, Yueyang count and reed plantation in
Xiaofanzhou, Changde count, were analyzed to determine the food composition by the
method of microhistological identification.
The vole lived in Carex f lats during spring and winter . The major food items of the
voles were consisted of Carex spp. and Cardamine hirsuta. Voles ate more Carex spp.
during spring (71.05% of diets) than during winter (68.97% of diets). Contrarily, Cardamine hirsuta of diets in spring (13.81% ) was less than that in winter (29.21% ). The voles primarily took monocot in spring (77.26% ) and winter (69.05% ). Leaves were always the most favorite food of the vole, the bulk of plant leaves in the animal diet was more than 91% in spring and winter.
In rice f ield, Monocot food items constituted 93.45% ( in summer) and 86.52% ( in
autumn) of diets of the voles. The major food items of the voles were rice (74.54% in
summer and 68.42% in autumn ) and Paspalum distichum ( 13.16% in summer and
11.24% in autumn). Leaves were dominant in diets in summer. Bu t the voles turned to
take seeds heavily (51.94 %) and the bulk of leaves (46.48% ) in diets reduced in autumn.
In hill habitat during summer, the numbers of food items which voles ate were
fourteen; Trisetum bifidum (36.98% of diet s) , Erigeron annuspers (23.61% ) and rice
(14.51% ) was major food items of the voles. The voles heavily used leaves (99.68% )and monocot (65.63% ) in this season. During autumn, monocot food items (60.68% )
were still more than dicot (26.48% ) in the voles diet s, but the numbers of food items of
the voles and leaves in the diets (48.69% ) reduced, accordingly the bulk of seed in diets
(35.57% ) signif icantly increased. Moreover, bark in diets of voles in au tumn were found.
In reed plantation during spring, the voles primarily ate Cardamine hirsuts
(42.81% ) , Phalaris arund inacea (20.17% ) , M iscanthus saccharif lorus (15.05% ) and Carex spp. (10.49% ). The voles used more dicot food items (54.29% ) than monocot (45.71% ). The voles heavily took plant seeds (34.50% ) , however the bulk of leaves (61.20% ) was still dominate in the voles diets.All of these indicated that the voles could shift food habit swith the variation of season and location.

Key words: Microtus fortis calamorum, Food composition, Dongting lake area