Trophic interactions of the endangered Southern river otter (Lontra provocax) in a Chilean Ramsar wetland inferred from prey sampling, fecal analysis, and stable isotopes

摘要: Non-invasive methodological approaches are highly recommended and commonly used to study the feeding ecology of elusive threatened mammals. In this study, we use multiple lines evidence assess strategies endangered Southern river otter, by determining seasonal prey availability (electrofishing), analysis undigested remains (spraints), stable isotopes (δ15N δ13C) in otter spraints (n = 262) a wetland ecosystem southern Chile (39°49′S, 73°15′W). Fecal isotopic analyses suggest that diet is restricted few items, particularly less-mobile, bottom-living, larger such as crayfish (Samastacus spinifrons, 86.11 %) crabs (Aegla spp., 32.45 %), supplemented opportunistically cyprinids (Cyprinus carpio, 9.55 catfish (Diplomystes camposensis, 5.66 %). The results specialized bottom foraging. Isotopic signatures food sources feces revealed mid-upper trophic position for with either higher or lower δ15N values than their potential items. δ13C otters were less enriched resources. We due narrow niche possible dependence on only species may be vulnerable reduction its populations. Finally, maintaining ecological interactions between considered central priority survival carnivore mammal.