Rudolf the Red-Nosed Reindeer

A special (UV) Christmas story

by Marcel Jansen, School of BEES, University College Cork

For generations, Rudolph the Red-Nosed Reindeer has been a beloved Christmas character. The story of Rudolf, first written and published by Robert L May in 1939, describes how Rudolf’s luminous red nose illuminates the way for Santa’s sleigh through the dark winter night. Robert L May’s story displays a fair amount of poetic licence, however, there is a grain of truth in the seasonal story. Yet, as became apparent in the early 2010s, it is not the nose, but it is the eyes of reindeer that enable these magnificent animals to see where Santa would have been in the dark!

Photo by Nicolas Lafargue on Unsplash


Reindeer have specifically adapted eyes, with ultraviolet (UV) transparent cornea and lenses, and UV-sensitive retina that extend their vision in to the UV-wavelengths of the solar spectrum. This enables the reindeer to find their way, and perceive food and predators in the dark Arctic winter, where the dim solar light is relatively enriched in the UV part of the spectrum. Reindeer, together with a range of other animals such as bees, bumblebees, rodents and birds, can actually see where humans are in the dark.

The School of BEES has a proud tradition of research in the complex ecological role of UV-radiation in the natural world. Prof Jansen in the School of BEES is co-author of the UNEP-assessment reports on the environmental effects of UV-radiation. These UNEP-reports are in fulfilment of the Montreal protocol on protecting the stratospheric ozone layer, and assess the various effects of UV light. BEES scientists are thus directly informing the important policies that protect the stratospheric ozone layer, and avoid exposure of our world to dangerously high levels of UV.

Photo by Fabio Porta on Unsplash


The group of Professor Jansen has taken UV research one step further, by exploiting UV as a tool to manipulate plants. Plants, like reindeer, perceive UV radiation and the group of Prof. Jansen is studying how exposure to UV light can increase the quality of glasshouse crops, for example by improving flavour and colour. As part of the SFI funded UV-SINTEC project and together with Dr Alan Morrison in the UCC School of Electric and Electronic Engineering, novel, energy-efficient LED-based UV-lamps are developed, and these are used to test the impact of UV-light on crops. Improvement of crop quality is particularly important in the winter months, when some glasshouse produce can be lacking in flavour. Thus, it might not quite be the shine from Rudolf’s nose that delivers your Christmas presents, but it is UV research in BEES that improves the quality of your Christmas dinner!

Happy Christmas,
Marcel Jansen

UV LED for Crops Research Group

School of Biological, Earth and Environmental Sciences, University College Cork, Distillery Fields, North Mall, Cork, Ireland, T23 TK30