True metabolizable energy of American black duck foods

Abstract

ABSTRACT Understanding the true metabolizable energy (TME) of foods is critical to estimating the energetic carrying capacity of landscapes for migrating and wintering waterfowl. We estimated gross energy, nutrient composition, and TME N (TME corrected for zero nitrogen balance) for 7 foods that are commonly found in the diet of American black duck ( Anas rubripes ) and other waterfowl wintering along the Atlantic Coast. TME N values ( ± SE) were 3.66 ± 0.12 kcal/g for mummichog ( Fundulus heteroclitus ), 2.02 ± 0.12 kcal/g for grass shrimp ( Palaemonetes intermedius, P. pugio , and P. vulgaris ), 1.57 ± 0.11 kcal/g for fiddler crabs ( Uca minax, U. pugilator , and U. pugnax ), 1.42 ± 0.13 kcal/g for sea lettuce ( Ulva lactuca ), 1.39 ± 0.12 kcal/g for saltmarsh cordgrass seeds (S partina alterniflora ), 1.10 ± 0.14 kcal/g for widgeon grass vegetation ( Ruppia maritima ), and 0.77 ± 0.16 kcal/g for saltmarsh snails ( Melampus bidentatus ). TME N estimated for foods in this study will assist conservation planners in carrying out bioenergetics modeling along the Atlantic Coast. © 2014 The Wildlife Society.