Jones, Orrin E.Castelli, Paul M.Williams, Christopher K.2023-12-112023-12-112011-12-01Orrin E. Jones, Paul M. Castelli, Christopher K. Williams; Observed Herring Gull Kleptoparasitism of American Black Ducks. Journal of Fish and Wildlife Management 1 December 2011; 2 (2): 196–198. doi: https://doi.org/10.3996/062011-JFWM-0351944-687Xhttps://udspace.udel.edu/handle/19716/33679This article was originally published in Journal of Fish and Wildlife Management. The version of record is available at: https://doi.org/10.3996/062011-JFWM-035Herring gulls Larus argentatus were observed to kleptoparasitize American black ducks Anas rubripes feeding on fiddler crabs Uca pugnax in coastal New Jersey. Although widespread in Laridae, kleptoparasitism has never been described between these two species. Over two winters of intensive 24-hour behavioral observations, this interaction was observed on two occasions during similar tidal conditions. Although this appears to be a rare interaction with limited energetic consequences, we note that quantifying these uncommon interspecific interactions is a benefit of thorough behavior observations, which may refine estimates of daily energy expenditure.en-USherring gullkleptoparasitismAmerican black ducklife on landArticle