Seals and sealions depend on their whiskers for a sense of touch when getting around underwater. As G. Dehnhardt of the University of Bonn, Germany and colleagues show in a report in the Journal of Experimental Biology, a seal?s whiskers, or vibrissae, are so important, that they are kept at a suitably warm operating temperature - even at the risk of losing heat to the icy waters in which seals sometimes find themselves.
Everyone knows how quickly the cold sucks the fine discrimination of touch from ungloved human fingertips. Below about 20 °C, the nerve-endings responsible for touch tend to lose their effectiveness. In the cold, blood drains from the surface, to minimize loss of heat to the exterior. Despite their obvious differences, human fingertips have a lot in common with the whiskers on the snout of a seal - the kinds and arrangement of tactile nerve endings are remarkably similar in both human fingertips and seal snouts, and several experiments have demonstrated that they have comparable sensitivity. Does this extend to cold-weather performance? Does a seal?s whiskers go numb with cold, just like human fingertips?
This is a preview of subscription content, access via your institution