![\"sage-thrasher-7952\"](\"http:\/\/featheredphotography.com\/blog\/wp-content\/uploads\/2012\/04\/sage-thrasher-7952.jpg\" "\\"sage-thrasher-7952\\"")
<\/a><\/p>\nThis is what a normal bill on a Sage Thrasher looks like.\u00a0 Notice that the upper mandible is slightly longer than the lower one with a curved tip\u00a0at the terminus and that both mandibles fit together tightly showing no evidence of a gap between them.<\/p>\n
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But in this thrasher the upper mandible is significantly shorter than the lower and the\u00a0curve of the two mandibles doesn’t match so they don’t fit\u00a0together well, leaving a gap.\u00a0 This is\u00a0definitely not<\/em>\u00a0a temporary, voluntary\u00a0position 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.\u00a0 The two mandibles never fit together cleanly and the upper one is definitely shorter.<\/p>\n <\/p>\n <\/p>\n With this head turn you\u00a0can see the other side.\u00a0 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.<\/p>\n <\/p>\n <\/p>\n An extreme crop of the previous image.\u00a0 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.\u00a0 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 is exactly\u00a0the same color as the background…<\/p>\n <\/p>\n <\/p>\n Another example of a bill deformity – this time in a Red-winged Blackbird.\u00a0 Notice the crossed mandibles which is definitely not normal.<\/p>\n <\/p>\n <\/p>\n And some of you may recall this Red-tailed Hawk we found last fall in the west desert.\u00a0 This bird apparently had “long-billed\u00a0syndrome” – more about the condition here<\/a>.\u00a0 And here<\/a>.\u00a0 We contacted several bird conservation and research groups about the possibility of trapping this bird to see if anything could be done for it but in the end the consensus was to not make such an attempt.\u00a0 This hawk was still actively feeding (we watched it catch and eat several voles) and it hung around the general vicinity for several weeks before it apparently moved on.<\/p>\n I\u00a0find this apparent increase in bill deformities disturbing, as do\u00a0some of the experts we were in contact with about the hawk.\u00a0 The cause(s) is unknown.<\/p>\n Ron<\/p>\n","protected":false},"excerpt":{"rendered":" I’m seeing more bill deformities “out there” than I used to and that disturbs me.\u00a0 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.\u00a0 Notice that the upper mandible is slightly longer than the lower one with a curved tip\u00a0at 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\u00a0curve of the two mandibles doesn’t match so they don’t fit\u00a0together well, leaving a gap.\u00a0 This is\u00a0definitely not\u00a0a temporary, voluntary\u00a0position 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.\u00a0 The two mandibles never fit together cleanly and the upper one is definitely shorter. With this head turn you\u00a0can see the other side.\u00a0 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.\u00a0 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.\u00a0 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…<\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n