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 | | Lesser Black-backed Gull and Baltic Gull are specifically distinct based on qualitative differences in morphology and differences in moult, foraging and breeding behaviour (Barth 1968, Bergman 1982, Cramp and Simmons 1983, Hario 1992, Strann and Vader 1992). |
 | | Heuglin's Gull L heuglini is specifically distinct from Lesser Black-backed Gull, Baltic Gull, Armenian Gull L armenicus, Pontic Gull L cachinnans, Yellow-legged Gull L michahellis and Vega Gull L vegae based on qualitative differences in morphology and behaviour, and differences in ecology (Grant 1986, Filchagov et al 1992, Hario 1992, Kennerley et al 1995). |
 | | Herring Gull, Vega Gull and American Herring Gull L smithsonianus are specifically distinct based on qualitative differences in morphology and vocalizations (Frings et al 1958, Hoffman 1979, Grant 1986, Mullarney 1990, Kennerley et al 1995, Dubois 1997). |
| www.dutchbirding.nl /comm/csna/tax2.html (2157 words) |
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