杂色山雀亲代喂食与子代乞食间的行为

在育雏期,晚成鸟的子代一般都是由双亲共同来抚育,子代为了更好地存活,会用自己的方式竞争获得更多的食物和更好的生存空间,同时亲代也会根据子代的乞食信号来分配食物。2011年3～7月采用针孔摄像技术录制了杂色山雀(Parus varius)育雏期巢内亲代与子代间的行为,统计了亲鸟站位、雏鸟站位、雏鸟乞食强度及亲鸟的喂食情况等数据。分析结果表明:(1)雌雄亲鸟在巢中的站位各有特点,雄鸟在整个育雏期都喜欢站在距离巢口较近的位置;雌鸟站位不太固定,前期离巢口相对较远,中期和后期离巢口相对较近;(2)雏鸟离亲鸟越近,乞食强度越大,获得食物的机会就越多;离亲鸟越远的雏鸟越不爱乞食,所以站位对雏鸟的食物获得影响最大;(3)雌鸟承担主要的育雏任务,喂食频率远大于雄鸟;(4)育雏期的不同阶段雏鸟乞食强度、亲鸟喂食频率变化很大:中期雏鸟乞食强度最大,亲鸟喂食频率最高,后期雏鸟乞食强度最弱;(5)整个育雏期雌性亲本没有表现出明显的偏爱行为,但雄性亲本在中、后期更偏爱体型大的雏鸟。可见杂色山雀子代的行为和体型大小影响着亲代的食物分配,亲代也会根据雏鸟日龄调整站位和喂食行为。

The Behavior of Parental Feeding and Offspring Begging by Parus varius

Nestlings raised by parent compete for food or for better position in the nest to get the best chance of survive. Meanwhile, parents deliver food by the begging signal of nestlings. To investigate the behavior of parent-nestling we video recorded the position of parents and each nestlings, begging intensity, feeding frequency of each nestlings in 10 broods of the Parus varius from March to July in 2011. Our results showed that: (1) paternal and maternal adults took a different position when they deliver food. Paternal adults preferred to position near the nest entrance. In contrast, maternal adults changed their position, they stood far away from the nest entrance in the early stage and moved close to the entrance in the mid and late stage; (2) nestlings that were closer to parents begged more intensely and had a higher probability of receiving food; nestlings farther from parents begged less. Therefore, position of the nestlings had greatly influence on the food receiving; (3) females delivered food with a significantly higher frequency than males; (4) the begging intensity was varied at different nest stage, higher in the earlier and lower in the later period; (5) females showed no preference on the size of nestlings, whereas males preferentially provided food for the largest-sized nestlings. The food-distribution pattern in P.varius was determined by nestling behavior and body size, and parents also adjusted their positions to deliver food as the nestlings growing.