Abstract
Seasonal selection of forages by red deer (Cervus elaphus) and roe deer (Capreolus capreolus) was studied in relation to availability and chemical composition in coniferous-deciduous forests of northeastern China from 1991 to 1992. Forage availability varied significantly among seasons. It was greatest in summer (168.4 and 160.3 g dry matter/m2 for red deer and roe deer, respectively) and smallest in winter (22.9 and 22.4 g dry matter/m2 in clearcuts, and 21.3 and 16.5 g dry matter/m2 in matured forests for red deer and roe deer, respectively). Red deer selected forbs in summer and autumn (p < 0.05), and avoided sedges in summer, browses in spring and autumn, and ferns in summer and autumn (p < 0.05), whereas roe deer selected forbs during snow-free seasons, and avoided sedges in summer and autumn, browses in spring, and ferns during snow-free seasons (p < 0.05). In winter, red deer selected Pinus koraiensis, and avoided Tilia mandshurica (p < 0.05), whereas roe deer selected Salix spp. and Pinus koraiensis, and avoided Corylus mandshurica and Syringa amurensis (p < 0.05). Relationships between the electivity indices (EI) and chemical composition (CP, NDF, ADF, IVDMD and minerals) were explored for red deer and roe deer, using simple, multiple and stepwise regressions. Correlation between the EI and chemical composition varied among seasons and no consistent relationships were found for red deer or roe deer. Roe deer appeared to be more selective than red deer during snow-free seasons, and showed lower preference to ligneous browse plants than red deer. Consequently, roe deer ate more nutritious foods during snow-free seasons, but ate less nutritious foods during winter than red deer.
