Eilam David, Hagbi Zohar
George S. Wise Faculty of Life Sciences, School of Zoology, Tel-Aviv University, Tel Aviv 6997801, Israel.
Department of Psychological and Brain Sciences, Dartmouth College, Hanover, NH 03755, USA.
Biology (Basel). 2024 Oct 17;13(10):834. doi: 10.3390/biology13100834.
Hatching captive barn owl chicks underwent four developmental phases. In the first 10 days (phase 1), behavior consisted of lateral movements that gradually changed to forward progression and peaked a few days before and after eye-opening. This behavior resembled a general developmental pattern that characterizes other vertebrates. Chicks also underwent a postural change, from head bent underneath the ventrum to resting on the rear end of the trunk with the head lifted in the air. Then, once their eyes were opened, chicks became more stationary and preoccupied with visual exploration, manifested in lateral head movements and peering episodes (phase 2, until day 20). The latter behavior, which is also typical of mature owls when not on the wing, characterized the chicks' behavior after post-hatching day 20 (phase 3), when their flight and contour feathers grew, along with shedding the down plumage and standing tall. Development culminated in active flight, first observed by days 50-60 (phase 4). Altogether, during post-hatching development, barn owl chicks gradually shifted from egg posture to the adult upright body posture. At the same time, their behavior consisted of speciation from the general developmental pattern to the typical stationary barn owl behavior, and, finally, flight was incorporated.
人工孵化的仓鸮雏鸟经历了四个发育阶段。在最初的10天（阶段1），其行为包括侧向移动，这种移动逐渐转变为向前移动，并在睁眼前后几天达到顶峰。这种行为类似于其他脊椎动物的一般发育模式。雏鸟还经历了姿势变化，从头部弯曲在腹部下方到头部抬起，身体靠在躯干后端休息。然后，一旦它们睁开眼睛，雏鸟就变得更加静止，专注于视觉探索，表现为头部侧向移动和凝视（阶段2，直到第20天）。后一种行为在成熟的鸮类不飞行时也很典型，它是雏鸟在孵化后第20天（阶段3）后的行为特征，此时它们的飞羽和廓羽开始生长，同时褪去绒羽并站直。发育最终以主动飞行告终，最早在第50 - 60天观察到（阶段4）。总之，在孵化后的发育过程中，仓鸮雏鸟逐渐从蛋的姿势转变为成年的直立身体姿势。与此同时，它们的行为从一般发育模式演变为典型的静止仓鸮行为，最终学会了飞行。
