An article in the Dutch biology research journal Deinsea, an annual publication of the Natural History Museum of Rotterdam, based on a study published in 2012 in the same journal, discusses the physiology of ‘Why Rudolph’s Nose is Red’.
The new study, entitled ‘Rudolph the red nosed reindeer had a very bioluminescent nose. A reply to Van der Hoven et al. 2012’ by Neil Crooks, Claire E. Marriott, Hannah R. Clifforth, Zain A. Ahmed, Arnold Xhikola, Samuel G. Penny, and Angelo P. Pernetta at the University of Brighton, UK, explain:
“Research published in Deinsea by Van der Hoven et al. (2012) identifies the cause of Rudolph’s infamous red nose to be the consequence of hyperemia of the nasal mucosa induced by the exertion of pulling a heavy load […] due to the excessive stresses endured whilst flying with Santa Claus and the sleigh in tow resulted in cerebral and bodily hyperthermia, overworking the nasal cooling system, causing the nose to glow. Whilst we recognise van der Hoven et al.’s (2012) central tenet of highly vascularized nasal mucosa in reindeer (Rangifer tarandus) helping regulate nasal heat exchange, we concluded that this is unlikely to be the causal factor of Rudolph’s particularly iridescent appendage for multiple reasons (PDF).”