The Effect of Radio Transmitters on the Behavior of Common Murres and Razorbills during Chick Rearing

Abstract

We compared site attendance, length and number of absences from the colony, and prey delivered to the young of control Common Murres (Uria aalge) and others which carried radio transmitters that had either an external or internal aerial during chick rearing. Birds with the internal aerial behaved similarly to control birds. However, birds with the external aerial spent less time in the colony, were absent for long continuous periods, and often returned without a fish for the chick. This did not reduce fledging success because their mates compensated by increasing the food brought in. Fewer observations were made on Razorbills (Alca torda) with external aerial transmitters, but they indicated no profound effect on behavior.