An isotopic assessment of the feeding habits of free-ranging manatees

摘要: There is relatively little information available on how the relative importance of fresh, brackish, or marine environments may vary geographically individually with respect to manatee Trichechus manatus latirostris feeding ecology. As a first application stable isotope analysis determine diet composition wild manatees, skin from 25 carcasses and leaf tissue plant species were collected 4 regions in Florida analyzed for values carbon (δ 13 C) nitrogen 15 N) isotopes. Values δ C N measured plants ranged -0.8 ± 1.0 6.4 0.0‰ tissues -8.7 0.2 -28.3 0.1‰, respectively. A mix- ing model was applied estimate across different geographic regions, results (mean, all regions) indicated that, overall, manatees consumed 44% their and/or estuarine sources. Manatees living along central east coast obtained 100% sources, while animals recovered St. John's River system (NE region) ~50% freshwater suggesting that some time had been spent outside river basin. In conclusion, suggest even though have physiological requirement ingest fresh water, supply significant fraction food resources.