To be sure what is meant by a "thayeri" wingtip, see p9 below:
|Martin T Elliot ©|
|(1) The under-side of p10 on the far wing is a shade paler than the upper-side of the right wing. |
Brevard County, Florida. January.
Now consider the open wing on an individual with a thayeri wingtip:
The objective of this post is to discuss the underwing of individuals like the one pictured above.
|(3) Although the outer webs of p8-p9 are obscured by the inner webs of the adjacent primaries, it's clear from this image that the underside of p10 is paler than the upperside of the wingtip.|
UpperwingI've observed several adult type Herrings with primaries that appear paler than usual on the upper-side. It's these birds that I'd expect to have very pale under-wings, but that hasn't been my experience:
|(6) Another Herring with thayeri wingtip. Note the slaty-gray color to the upper primaries. Otherwise, this bird is a typical Herring in every respect. |
Porter County, Indiana. November.
|(7) Same individual above.|
|(8) Same individual above.|
|(9) Same individual above.|
|(10) Same individual above. Note how the under-side to the primaries has a similar shade to the upperside - not as strong of a contrast as I'd expect.|
|(11) Same individual above.|
Questions to Ponder
Clearly not all American Herring adults with thayeri wingtips show paler under-primaries. In fact I'd guess only a small minority do. A very important consideration is how much lighting (reflective properties of the under-primaries and over-exposure) is effecting what is seen in my images - something I'll have to pay extra attention to in the future.
- Are individuals with paler underwings (such as image #4 & 5) within range for American Herring?
- Do Herrings with non-thayeri wingtip patterns show pale under-primaries?
- Can the color to the upper-side of the primaries look like #6 & 7 in pure American Herrings?
- If these birds aren't Herrings, then what explanation can possibly be given for the lack of melanin in the wingtips?