Calving site characteristics and habitat use in Svalbard reindeer

Abstract

Migrating reindeer and caribou tend to return to traditional calving locations every spring with specific environmental conditions and protection of calving grounds is a central part of Rangifer conservation. In contrast, the non-migratory Svalbard reindeer inhabit an environment free of predators during calving season making them ideal as a reference population. Little is known about habitat characteristics within calving locations for Svalbard reindeer. The objectives of this study were therefore to first, identify the calving day and location of Svalbard reindeer using GPS relocation data, second, to describe the habitat characteristics in the estimated calving locations, and third, to investigate if females with multiple calving seasons return to the same calving location. Using recursive partitioning and first passage time to estimate calving day, I found that Svalbard reindeer in northern locations calve significantly later in June compared to reindeer located 100 km south, in Nordenskiöld Land. Individual habitat selection analysis demonstrated little difference in habitat selection for females with and without calves during the immediate calving period in any of the study areas. Nordenskiöld Land females tended to select for calving locations with higher than average proportion of moss tundra, flatter and lower elevated areas, while females in northern locations tended to select calving locations with more heath cover and high NDVI. The Svalbard reindeer returned to the same valley or adjacent areas (i.e. side-valleys) to calve for the next calving season. This thesis provides knowledge on important habitat characteristics for reindeer calving locations and can provide management with information to restrict human activity within areas critical for Svalbard reindeer reproduction.