The summer diet of moose Alces alces in Agder, south Norway - the link to fragile bones and kidney damages?

Reported cases of fragile bones and kidney damage from the Agder counties, south Norway, motivated this study of the diets of radio-collared moose Alc es alces Linnaeus, 1758 during summer 1995. Birch Betula pubescens (39.8%), bilberry Vaccinium myrtillus (13.3%), and bog asphodel Narthecium ossifrag um (10.8%) were the main plants eaten, but only birch and bog asphodel were preferred when use was compared to relative availability. Bog asphodel is highly toxic and has been reported to cause severe kidney damage in domesti c sheep Ovis aries and cattle Bos taurus. Hence, we hypothesized high level s of bog asphodel in the diet of moose in Agder is the link to kidney damag e frequently reported from this area. However, laboratory studies have not documented damage to the skeleton from high intake of this species, and we therefore hypothesized fragile bones are caused by other factors than eatin g bog asphodel.