Svalbard Reindeer. Photo credit: Randal Hyman in SmithsonianMag.

By Chiara Muzzi

As we close the door behind us and sit by the fire after a fruitful day of Christmas shopping, our hearts warmed by the mulled wine drank at the winter market, the memory of children staring in amazement at reindeer in the town square still lingering – it is at this moment that we may feel overcome by the Christmas spirit and ponder whether this could ever change.

This past year has been the scene of much change: the emergence of post-truth politics and unexpected political choices, conflicts and the refugee crisis, a changing climate and the warmest year since records began. All these issues are connected, and while climate change is now a concept that most families would have heard of, it may not yet be widely accepted nor its effects or causes understood.  At present the most understood and visible impact is that on weather patterns: what were previously rare weather events, now are seen more frequently and with a higher intensity: floods, droughts, storms, freezing. The impact is soon going to be felt on insurance premiums, food production and water resources, as well a with forced migration of climate refugees. Nature itself will be affected, our biodiversity will be impacted. And so will be Santas’ reindeer.

Svalbard is an archipelago halfway between continental Norway and the North Pole and its reindeer population has been affected by climate change. This beautiful subspecies of reindeer is the smallest around and has become increasingly smaller, falling from 55 kg (121 lb) in the 1990s to 48 kg (106 lb) today.

Location of Svalbard (Norway. Image credit: Wikipedia.

The warming climate has a two-way effect on the reindeer population: on the one side the warmer summers have an effect on the food sources by allowing for plants to flourish more than usual. The increased availability of food has a positive effect on body mass and on fertility, leading to a higher population. Because the gestation period is around 7 months, the birth of the increased population coincides with the colder season – a time in which what used to be reliable snow is now more often rain, known as rain-on-snow (ROS). This winter rain turns into ice and renders access to food sources difficult and unreliable. As a consequence, winter maternal body mass decreases and this has been shown to affect calf production. The fertility increase in the warmer months is followed by weaker mothers and newborn calf in the colder months – i.e. a higher population with a decreasing body mass. The heavy rain-on-snow (ROS) phenomena is an extreme climatic event that is expected to become increasingly frequent with warming in the Arctic, making Svalbard reindeer vulnerable, and shrinking.  

Having more reindeer is also likely to increase competition for the scarce food sources. Some coping mechanisms will include wider spatial movement in the population when possible, which may lead to an increase in encounters with the polar bear, also a resident of Svalbard.  Although at present polar bears are predators of marine mammals, particularly seals, response to a decrease in their ideal foodsource could lead to a behavioural plasticity and to increased attacks on reindeer.

Climate change may thus change the way Santa Claus travels to reach our homes. Do not be surprised if he gets to your home with delay.