USE OF HABITAT, SIZE OF PREY, AND FOOD-NICHE RELATIONSHIPS OF 2 SYMPATRIC OTTERS IN SOUTHERNMOST CHILE

In Magallanes (southernmost Chile), the marine otter Lutra felina tend s to use more open and wave-exposed coastal areas, whereas L. provocax is found in more protected habitats. To investigate the hypothesis th at the two species segregate habitats to avoid competition for food, w e surveyed the available literature on food habits and analyzed food-n iche relationships of both species of otters in Magallanes. Overlap of diet between species of otters was relatively high, and L. provocax t ended to have a narrower diet than L. felina. Both species consumed pr ey of similar size. These findings are consistent with tile use of dif ferent habitats to avoid competition for food resources. However, alte rnate models, including habitat segregation resulting from differentia l abilities of the two species at catching prey in more wave-exposed h abitats, deserve some attention. Our analysis also revealed that niche breadth and size of prey taken by L. felina at three sites along the Chilean coast were relatively similar At Chiloe, however, L. felina ex hibited the narrowest diet and consumed tile largest prey. Although su ch a difference might be related to variation in abundance of prey amo ng localities, it may also have resulted from the relatively small sam ple available for Chiloe.