Reindeer calving in enclosures : effect on the mother's activity

Abstract: Reindeer (Rangifer tarandus spp.) are a migratory species, which have a high fidelity to their calving grounds. They therefore return to calve in the same location each year. In Sweden, all reindeer (Rangifer tarandus tarandus) are herded within a pastoral and extensive system. There are reindeer herding communities, which herd their reindeer to the mountain region in summer and to the boreal regions in winter, and there are forest reindeer herding communities, which keep their herd in the boreal regions throughout the whole year. A larger project at the Swedish University of Agricultural Sciences presented an opportunity to observe reindeer calving in enclosures in both Udtja and Gällivare forest reindeer herding communities. The aim was to observe reindeer behaviour around calving and investigate whether or not calving in enclosure affects reindeer behaviour and movements around calving. To track the movements of the reindeer, 25 reindeer in total were equipped with GPS-collars in both Udtja and Gällivare enclosure and in addition in a freely ranging herd in Udtja. Specifically, female residence time (RT) and step length (distance between adjacent GPS-positions) were calculated as an indication of reindeer movement around calving and overall movement during the period 5 May to 30 May. RT was used to define a calving event and quantify the amount of time spent by the reindeer cow and her calf in close proximity of the calving place, after calving. The mean RT was significantly greater in the freely ranging herd than the pooled data from the two enclosures, but no significant difference was found between the freely ranging herd and the reindeer in the Udtja enclosure. There was no significant difference of mean RT between the two enclosures either. Gällivare enclosure also had a significantly greater mean step length value than the freely ranging herd, and the difference seemed to be greatest around feeding in the morning. In conclusion, reindeer calving in enclosure seem to have the potential to affect reindeer behaviour in a negative way by decreasing their residence time and increasing step length. However, an enclosure with more flat grounds and less wetlands and mires seem to be preferable if calving in enclosure is necessary, as it seems to let reindeer activity be more in harmony with their activity patterns in their natural habitat.