Brown Thrasher With An Unusually Long Bill

This afternoon at A.D. Barnes, in Miami, we came across a Brown Thrasher with an unusually long bill -- like, several times too long. Unfortunately, none of the pictures convey its full magnitude, because they're either taken at an angle, or the tip is obstructed. If anybody knows any conditions that might be responsible for this, or whether abnormalities of this nature are at all common for thrashers, or mimids, generally, please  let us know in the comments.

UPDATE:
For anyone interested, Bill Pranty has been kind enough to share two articles on the subject of abnormal bill length in Florida's Brown Thrashers:

http://www.fosbirds.org/FFN/PDFs/FFNv04n1p11-13Brown.pdf
http://www.fosbirds.org/FFN/PDFs/FFNv01n2p6-8Taylor.pdf