This presumed hybrid Great Black-backed Gull (Larus marinus) x European Herring Gull (Larus argentatus) was seen on 20 March 2011 at Vejle Harbour in Denmark.
Considering the massive amount of variation shown by some gull species, mixing genes can create quite a mix of plumage features. However, sometimes they can be surprisingly easy to figure out. This is due to the fact that a significant percentage of hybrids show obvious intermediate characters compared to the parent species.
While most birds of the Great Black-backed Gull x European Herring Gull combination give the impression of being a Great Black-backed-like gull with an intermediate mantle, it is also possible to find birds that are structurally more similar to Herring Gull (as shown below). The darker mantle of this hybrid alerts the observer to something interesting. However it is clearly much too pale to be a Great Black-backed Gull. The size (and relatively large bill) combined with pink legs, squarish head and primary pattern; seem to exclude a Lesser Black-backed parentage, leaving little doubt to this identity.
Other possible GBBG x EUHG hybrid candidates can be found here, here, here, here, and here.
Considering the massive amount of variation shown by some gull species, mixing genes can create quite a mix of plumage features. However, sometimes they can be surprisingly easy to figure out. This is due to the fact that a significant percentage of hybrids show obvious intermediate characters compared to the parent species.
While most birds of the Great Black-backed Gull x European Herring Gull combination give the impression of being a Great Black-backed-like gull with an intermediate mantle, it is also possible to find birds that are structurally more similar to Herring Gull (as shown below). The darker mantle of this hybrid alerts the observer to something interesting. However it is clearly much too pale to be a Great Black-backed Gull. The size (and relatively large bill) combined with pink legs, squarish head and primary pattern; seem to exclude a Lesser Black-backed parentage, leaving little doubt to this identity.
Other possible GBBG x EUHG hybrid candidates can be found here, here, here, here, and here.
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