The icing of external recorders during the polar winter

• Main Authors: Kooyman,Gerald L., Ponganis,Paul J.
• Format: Report
• Language: English
• Published: Scholander Hall, 0204, Scripps Institution of Oceanography/Scholander Hall, 0204, Scripps Institution of Oceanography 2004
• Subjects: Emperor penguins; Memoirs of National Institute of Polar Research; Polar Research; Sea ice
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2492; http://id.nii.ac.jp/1291/00002492/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2492&item_no=1&attribute_id=18&file_no=1

Recorders and transmitters are commonly attached to suitable polar species of vertebrates. When using these devices, power and memory are two of the most limiting factors in successful experiments. To conserve power and memory the units are often programmed to record or transmit at designated times. A commonly used sensor is operational only when the animal is in sea water. For this procedure to function properly, exposed electrodes close a circuit when the attached device is wet. Using satellite transmitters that were programmed to transmit only after they were dry for a prescribed time, we noted an uncommon number of failures in transmission. On later controlled experiments using captive emperor penguins, Aptenodytes forsterii, we found that mock transmitters formed a glaze of ice over their surface while the birds were diving freely into an ice hole cut in two meter thick sea ice. We concluded that the icing caused the sensor to fail in detecting when the birds had re-entered the water. Icing could be an important factor in successful use of attached recorders and transmitters on polar animals, especially in winter.