I spent a few hours at the BP Refinery in Whiting, Indiana on Saturday. Highlights included a good count of 13 Great Black-backeds, an adult type Glaucous, a presumed GBBG x Herring and a Kumlien's/Thayer's type.
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Clearly a shade paler than the pure GBBGs, the dark-backed gull (front-right) seen here is likely a GBBG with some pale-backed genes. Whether this is Herring or Glaucous influence (the two most likely mixes) is not clear. |
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Four of thirteen GBBGs on Whiting Beach. Whiting, IN is one of the best sites to see Great Black-backeds on southern Lake Michigan. The birds are very skittish here, but can be found on the east side of the beach in relatively good numbers. |
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First cycle Great Black-backed. |
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Adult type Glaucous Gull (still growing outer primaries and central secondaries). |
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Adult Bonaparte's Gull. It's getting a bit late for Bonnies on Lake Michigan, but there are still a few filtering through. |
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My favorite bird of the day, I couldn't decide whether I wanted to call this a Thayer's or dark Kumlien's/Thayer's intergrade. |
The wingtip pattern is fine for Thayer's (and that's probably what it will be logged as), but the pigmenation to the wingtips was a bit more slaty than I like. In particular, the outer web to P10 (which I expect to be dark) was wahed out and dark gray:
But as is always the case, at different angles, the bird appeared darker (especially from behind):