ABSTRACT. The research examines reindeer feeding practices and herders' learning of them in three herding co-operatives in Finland: Kuukas in the south, Oraniemi in the central area, and Hammastunturi in the north. In the southern and central co-operatives, from the late 19th century until the Second World War (1939 -45), trees rich in lichens were cut to provide emergency forage. Harvesting lichens from trees and feeding associated with "tether calving" and "fence calving" have been common in the central and northern co-operatives. In the 1960s and 1970s, poor digging conditions resulted in reindeer losses, and pressure to feed reindeer increased further as forestry practices and overgrazing caused pastures to decline. Large-scale feeding entered daily practice in Kuukas and Oraniemi in the late 1980s and mid-1990s. The increased interaction between humans and reindeer brought about by regular feeding has made the animals tamer. In fact, they have adopted the permanent feeding areas as part of their pasture rotation. In Hammastunturi, herders entice reindeer from one pasture to another by providing supplementary forage. Knowledge about feeding developed in close concert with agriculture, and was transferred from south to north in the 1980s and 1990s. We argue that feeding practices draw on traditional ecological knowledge, which includes old ways of herding cattle. Herders' personal working practices and training are knowledge that is difficult to describe in words and must be learned by experience. Learning to feed reindeer requires not only familiarity with herding in practice (which implies profound knowledge about the animals, their nutrition, digestion, behavior, and handling), but also familiarity with the herding district and co-operation across generations.Key words: reindeer herding, winter feeding, lichen, Finland, boreal forest, interview, local knowledge, learning, anthropology, biology, multidisciplinary RÉSUMÉ. Cette étude porte sur les pratiques alimentaires du renne et sur l'apprentissage qu'en font les bergers au sein de trois coopératives de la Finlande : Kuukas dans le sud, Oraniemi dans la région du centre et Hammastunturi dans le nord. Dans les coopératives du sud et du centre, de la fin du XIX e siècle jusqu'à la Seconde Guerre mondiale (1939)(1940)(1941)(1942)(1943)(1944)(1945), on coupait des arbres riches en lichen pour servir de fourrage d'urgence. La récolte du lichen des arbres et l'affouragement lié au «vêlage en laisse» et au «vêlage en enclos» sont courants dans les coopératives du centre et du nord. Dans les années 1960 et 1970, les mauvaises conditions de creusage se sont traduites par la perte de rennes, et la pression exercée pour faire manger les rennes a augmenté au fur et à mesure que les pratiques d'exploitation forestière et le surpâturage ont réduit la taille des pâturages. L'affouragement à grande échelle est devenu monnaie courante au quotidien dans les coopératives de Kuukas et d'Oraniemi vers la fin des années 1980 et le milieu des années 1990. L'interaction accrue e...