Prized for their impressive antlers, red deer have been caught in the hunters' sights for generations. But a deer's antlers are much more than decorative. They are lethal weapons that stags crash together when duelling. John Currey, from The University of York, UK, has been intrigued by the mechanical properties of bone for over half a century and has become fascinated by the mechanical properties of antler through a long-standing collaboration with Tomas Landete-Castillejos at the Universidad de Castilla-La Mancha. 'Antlers look as if they are dry,' says Currey, 'but no one knew if they really are dry when used in contests'. Curious to find out whether red deer antlers are used wet or dry when duelling, and how this affects the antlers' mechanical properties, Currey headed south to La Mancha to test the mechanical properties of red deer antlers and publishes the discovery that dry antler is stiff and tough on 27 November 2009 in the Journal of Experimental Biology at http://jeb.biologists.org.
But before the team could begin testing the antler's strength, they needed to find out how dry the bones were. Collecting freshly cut antlers from the university farm and a local game estate just after stags had shed the antler's protective velvet, Currey, Landete-Castillejos, Jos Estevez and their colleagues weighed the antlers each week to find out how much they dried. Amazingly, over the first 2 weeks, the antlers lost a colossal 8% of their weight, compared with 1% weight loss if they were cut at other times of the year. Eventually the weight loss stabilised and the antler's humidity was in balance with that of the surrounding air. It was clear that the antlers were dry when the stags began duelling.
But how did this water loss affect the bone's material properties in comparison with those of normal bones, which function internally and are always wet? Would the dry antler make a better weapon than wet b
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The Company of Biologists