扎龙保护区春季丹顶鹤觅食的农田生境利用分析

为了更深入地了解候鸟丹顶鹤春季利用的农田生境情况,以期为后续的该时期鹤类监测及觅食农田而产生的补偿评估奠定基础并制定相应的管理策略,2002—2015年的5月采用定点观察法、二维坐标法、样方法、GPS定位和因子分析等方法,对扎龙保护区丹顶鹤春季利用的农田生境特征进行了调查。分析结果表明:(1)春季,丹顶鹤觅食偏好选择的农作物为玉米(100%),偏好选择2—5片叶(94.32%)、回避1片叶和超过6片叶(100%)的玉米苗;(2)丹顶鹤觅食利用的农田生境通过有效食物因子和干扰因子进行判定;(3)有效食物因子包括作物高度、作物密度、作物面积、距明水面距离、距芦苇沼泽距离等;其中,选择的作物密度约为8—10株/m~2、作物高度为6—7cm,作物面积4—50hm~2大小不等、距明水面和芦苇沼泽距离相似约为0.4km左右;(4)干扰因子包括季节性弱干扰因子如道路等和强干扰因子如居民区等,针对弱干扰因子丹顶鹤采取不排斥的忽视方式,约保持在0.20km以上;针对强干扰因子丹顶鹤采取远离的方式进行回避,保持在1.20km以上。基于上述分析,建议扎龙保护区在春季巡护时应对人为活动区和农田给予更多的关注。

Springtime utilization of farmland habitat by red-crowned cranes in the Zhalong Nature Reserve

In order to deepen our understanding of the springtime utilization of farmland habitat by migratory red-crowned cranes (Grus japonensis), and to provide scientific data to support crane monitoring and farmland monitoring, the characteristics of the farmland habitat used by red-crowned crane during their spring migration (May, 2002-2015) was analyzed using the fixed-point observation method, the two-dimensional coordinate method, the sample method, GPS positioning, and factor analysis. The results showed that: (1) In terms of farmland habitat type, red-crowned cranes preferred maize crops (absolute foraging preference choice, 100%), preferred maize seedlings with 2 to 5 leaves (94.32%), and avoided seedlings with l leaf or more than 6 leaves (100%); (2) Selection criterion of farmland habitat were effective food factors and disturbance factors; (3) Important food factors included crop height, crop density, crop area, distance from lakes, and distance from reed marshes. For these factors, the preferred choices were 8-10 plants/m² for crop density, 6-7 cm for crop height, 4-50 hm² for crop area, and approximately 0.4 km for the distance from the lakes and reed marches; and (4) Disturbance factors included strong disturbance factors and weak disturbance factors. For residential areas (strong factor), red-crowned cranes avoided it by at least 1.20 km; for roads (weak factor), red-crowned crane did not avoid it, the disturbance to the weak disturbance areas was greater above 0.20 km. Based on the results of our study, we suggest that during the spring resource patrol and protection period of the Zhalong Nature Reserve, there should be more focus on the residential areas and farmland.