Tag: bill deformities
Bill Deformities
I’m seeing more bill deformities “out there” than I used to and that disturbs me. The latest example was a Sage Thrasher we found on Antelope Island four days ago. This is what a normal bill on a Sage Thrasher looks like. Notice that the upper mandible is slightly longer than the lower one with a curved tip at the terminus and that both mandibles fit together tightly showing no evidence of a gap between them. But in this thrasher the upper mandible is significantly shorter than the lower and the curve of the two mandibles doesn’t match so they don’t fit together well, leaving a gap. This is definitely not a temporary, voluntary position of the bill as I have about a dozen shots of the bird over a period of about a minute that show the same thing. The two mandibles never fit together cleanly and the upper one is definitely shorter. With this head turn you can see the other side. I can only imagine how this would interfere with normal preening as the bird attempts to draw the individual feathers through the bill to lock the barbs together. An extreme crop of the previous image. Notice how the back of the mandibles touch each other and prevent the rest of the bill from coming together because their curves don’t match along the entire length of the bill. At first I thought that the end of the lower mandible looked damaged or eroded but perhaps there’s just something on the bill that…
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Bill Deformities
I’m seeing more bill deformities “out there” than I used to and that disturbs me. The latest example was a Sage Thrasher we found on Antelope Island four days ago. This is what a normal bill on a Sage Thrasher looks like. Notice that the upper mandible is slightly longer than the lower one with a curved tip at the terminus and that both mandibles fit together tightly showing no evidence of a gap between them. But in this thrasher the upper mandible is significantly shorter than the lower and the curve of the two mandibles doesn’t match so they don’t fit together well, leaving a gap. This is definitely not a temporary, voluntary position of the bill as I have about a dozen shots of the bird over a period of about a minute that show the same thing. The two mandibles never fit together cleanly and the upper one is definitely shorter. With this head turn you can see the other side. I can only imagine how this would interfere with normal preening as the bird attempts to draw the individual feathers through the bill to lock the barbs together. An extreme crop of the previous image. Notice how the back of the mandibles touch each other and prevent the rest of the bill from coming together because their curves don’t match along the entire length of the bill. At first I thought that the end of the lower mandible looked damaged or eroded but perhaps there’s just something on the bill that…