Behavior of undisturbed 1‐ to 10‐day‐old chicks in different rearing conditions
Most of 11 measures of the behavior of undisturbed chicks showed a gradual increase in frequency of ocurrence between the 1st or 2nd and the 10th day. A group of 4 measures, associated with feeding, showed a peak at 6 days among isolated birds. These changes are related to studies of food reserve utilization and improvement in motor ability during this period. Group‐reared birds showed patterns of behavior change with increasing age similar to isolated, but showed them earlier. Chicks were reared in conditions of different visual complexity and their behavior watched while they were undisturbed at 6 days. Where a moving object had been visible to the chicks during rearing, their behavior was much affected. Such birds spent much time as near to that object as a perspex partition would allow. If the object had been moving continuously, the birds were active for more of the observation period than were birds in grey‐walled pens, but conditions that were identical except for the lack of movement had no such effects on behavior. Behavior development is changed and perhaps accelerated by certain increases in the complexity of a chick's environment. Copyright © 1968 John Wiley & Sons, Inc.