LBBG and leucistic or hybrid Canada Goose - SW MI 12/21

[chipperatl 682]

I think this first bird is a good candidate for juvenile Lesser Black-backed Gull.  Profile seems less HERG, and it looks a little bit smaller than the nearby HERGs, along with what looks like darker back.  

 

I tagged this as Domestic x CANG hybrid instead of leucistic.  I thought the rounder, larger head along with the orange legs and chunkier body leaned more towards some domestic goose background.  

[AlexHenry 1,826]

I wouldn't exactly say a 1st cycle Lesser Black-backed Gull has a darker back than 1st cycle Herring Gull, just more distinctly patterned - for example, the scapulars have broad white edges sharply contrasting with dark brown centers, giving a sort of "scalloped" look to the scapulars, while the greater coverts have horizontal brown bars on white or creamy feathers, giving a checkered or barred look to the coverts. Comparatively, Herring Gulls can range from fairly light to quite dark in first cycle plumage, but the patterning on the back and wings is generally less distinct, less organized, more washed out. Herring Gulls are more likely to be quite dark underneath. 1st cycle Herring Gulls which still have juvenile scapulars will look darker on the back than those that have molted their scapulars; it is possible to have both around this time of year.

Lesser Black-backed Gulls should also have a wholly dark bill, while Herring will likely have some pinkish or paler tones at the base.

I wouldn't be confident making a call from the pictures above, it looks like a possibility for Lesser Black-backed, but could well be a Herring Gull. It does look a little smaller in the top photo but there is always some degree of intraspecific variation.

Here is a range of 1st cycle Herring Gulls (top one is most juvenile type, others have begun some molting of scapulars) - 

Versus a 1st cycle Lesser Black-backed Gull - note the distinct patterning on the back, all dark bill -

 

Perhaps someone else can give a definitive answer, I'm just not confident given the distance of the photo.

[AlexHenry 1,826]

As for the goose varying degrees of white on the head and neck is not unusual for Canada Goose, but as you mention, the orange legs, the shorter, thicker neck, and the chunkier body especially in the breast area seem suggestive of some sort of domestic parentage. So I agree with your assessment.