Duckling responses to lake acidification: do black ducks and fish compete?

摘要: This study focused on two pairs of ponds in Maine, USA, that were physically similar but which had markedly different acidities. Salmon Pond (pH 6.3) fish, while 120 m away, Mud 4.5) was fishless. The second pair, Killman 6.5) and Unnamed 4.8), 14 km distant, also again the circumneutral pond fish acidic Imprinted black duck ducklings, Anas rubripes, kept grew faster than those ponds. Differences behavior indicated better duckling habitat. Ducklings spent less time searching moving, more feeding resting, ducklings There substantial overlap diets trout ducks; three indices calculated sharing a with to fish's Sweep-net samples invertebrate abundance comparisons benthic inside outside exclosure cages presence decreased abundance. These results support idea compete for invertehrates that, under certain circumstances, negative effect acidification may produce beneficial ducklings.