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机构地区:[1]齐齐哈尔招生考试委员会办公室 [2]黑龙江省科学院自然资源研究所
出 处:《齐齐哈尔师范学院学报(自然科学版)》1993年第3期45-48,64,共5页
摘 要:苍鹭为我省常见夏候鸟,每年3月中旬迁至我省,4月初开始产卵,每窝2~7枚,两性共同孵化.雏鸟晚成,刚出壳时很虚弱,亲鸟将半消化食物吐到嘴边才能吞食.10日龄体温恒定,知主动索食,20日龄行走平稳,出现等级观念,40日龄能作短距离飞行.50日龄各器官发育完善,能长距离飞行并开始学习觅食,60日龄已能独立活动,但仍需亲鸟抚育.Gray Heron (Ardea cierea)is a summer bird in Heilongjiang Province Nesting and brooding begin early in April. Nestlings are altricial ,and must be feeded by their parents. Nestlings are very weak when born. The body temperature starts to be constant in 10 days old,and they begin to feed initiatively. Their action abilities have increased in 20days old,and their walking is stable. Gradation sense appears. They can fly for a short distance in 40 days old. All organs have grown well in 50days old,and they can fly for a longer distance and begin to learn how to look for food. The food for them is mainly fish,and different in different days old.
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