Abstract:

Niche differentiation is an important ecological theory in explaining the coexistence of species. Schonenr believes that the spatial dimension has the highest influence on the formation of niche differences, followed by the nutritional dimension, and the time dimension is the last to be activated. To verify this hypothesis, we used the kilometer grid method to place 52 infrared cameras in the Longtangshan area of the Qingliangfeng National Nature Reserve in Zhejiang from December 2018 to November 2019. We monitored the populations of sympatric black muntjac and Reeves’ muntjac that have similar feeding habits. The average capture rate was calculated to analyze the differences in the species’ selection of vegetation type, altitude, slope position, and distance from water sources in different seasons. The nuclear density estimation method was used to analyze the daily activity rhythm and the degree of overlap in the activities of the two species. The results indicate that black muntjac and Reeves’ muntjac have different choices in spatial niche: black muntjac prefers mixed broadleaf-conifer forest, primarily inhabiting areas with high altitude between 1 301 - 1 500 m and avoiding areas with low altitudes and valleys. Activities of the black muntjac are frequent in areas closer to water sources. The Reeves’ muntjac prefers deciduous broadleaved forests, mainly inhabits areas with an elevation of 901 - 1 100 m, prefers mid-slope positions, avoids valleys, and has no obvious tendency towards choosing water sources. The black muntjac and the Reeves’ muntjac are both diurnal animals with morning and twilight activities, and the overlap of their daily activity rhythms throughout the year is relatively high (Δ4 = 0.86), and only lower in winter (Δ1 = 0.65). The above results support the hypothesis of Schonenr. First, spatial dimension has a greater impact on species niche differentiation than the temporal dimension. The black muntjac and Reeves’ muntjac in the Longtang Mountain area mainly choose different habitats to avoid overlapping territories and reduce the competition between both species. Secondly, there are seasonal differences in this model. In winter, due to the reduction of available resources, competition intensifies. Both species adjust their rhythm of daily activities to increase the degree of temporal niche differentiation in order to achieve coexistence in the same region.

Key words: Niche differentiation, Habitat selection, Daily activity rhythm, Black muntjac (Muntiacus crinifrons), Reeves’ muntjac (Muntiacus reevesi)

摘要：

生态位分化是解释物种共存的重要理论。Schonenr认为空间维度对生态位差异形成的影响程度最高，营养维度次之，时间维度则最后被启动。为验证这一假说，我们于2018年12月至2019年11月，在浙江清凉峰国家级自然保护区龙塘山区域采用公里网格法布设52台红外相机，对同域分布且食性相似的黑麂和小麂种群进行监测，计算平均拍摄率，分析不同季节黑麂和小麂对不同植被类型、海拔、坡位、水源距离的选择差异，并运用核密度估计法分析二者日活动节律及重叠程度。结果显示，(1) 黑麂和小麂对空间生态位的选择出现分化：黑麂偏好针阔混交林，主要栖息于1 301 ~ 1 500 m的高海拔地区，回避下坡位和谷地，在距离水源较近的区域内活动频繁；小麂则偏好落叶阔叶林，主要栖息于901 ~ 1 100 m的中海拔地区，偏好中坡位，回避谷地，对水源距离没有明显的选择倾向。(2) 黑麂和小麂均为晨昏性活动的昼行性动物，二者全年日活动节律重叠程度较高 (Δ4 = 0.86)，仅冬季较低 (Δ1 = 0.65)。上述结果支持Schonenr的假说：首先，空间维度对物种生态位分化的影响大于时间维度，龙塘山区域黑麂和小麂主要通过选择不同的栖息地来增加空间回避，降低二者的竞争；其次，这种模式存在季节差异，冬季由于可利用的资源减少，竞争加剧，二者通过调整日活动节律，增加时间生态位分化程度，从而实现同域共存。

关键词: 生态位分化, 栖息地选择, 日活动节律, 黑麂, 小麂