Co-feeding between Svalbard Rock Ptarmigan (<i>Lagopus muta hyperborea</i>) and Svalbard Reindeer (<i>Rangifer tarandus platyrhynchus</i>)

Abstract

Co-feeding between Svalbard rock ptarmigan (Lagopus muta hyperborea) and Svalbard reindeer (Rangifer tarandus platyrhynchus) on Svalbard, Norway, was observed during our annual point transect survey of territorial Svalbard ptarmigan cocks in two side valleys of Adventdalen and Sassendalen. Both pairs and single hens or cocks used the feeding craters excavated by reindeer in search of food. We suggest that the use of reindeer feeding craters may be important to the Svalbard rock ptarmigan during snow-rich events in winter or after terrestrial ice-crust formation resulting from mild spells and rain-on-snow events. We expect that such co-feeding may be particularly important for saving energy in periods when territorial defence and preparation for the breeding season make high energy demands on ptarmigan of both sexes.