Wednesday, July 29, 2009

Molting Mess!

Prothonotary Warblers (Protonotaria citrea) continue to be seen along the boardwalk at Audubon's Francis Beidler Forest, although they have become much quieter and are now more difficult to see. Many of the warblers that have been spotted in the past couple days are showing signs of molt. Several of the males spotted along the boardwalk did not have any tail feathers. You may also notice the color of the bill is changing from a jet black to straw-colored. It is a surprise to many that during the winter months Prothonotary Warblers do not have a black bill, but rather it is straw-colored.

The images show birds prior to molting and during the molting process.

Many adult birds molt their feathers at the end of the breeding season before heading south for the winter. Prothonotary Warblers only molt their feathers once per year and it typically occurs between early June and late August. In this way, the birds will have a fresh set of flight feathers for their long journey to Central or South America. Some of our Prothonotary Warblers have probably already embarked on their southward migration and most will have left Beidler Forest by the end of August.

Molting is not a pretty process, but it is critical and helps ensure that the Prothonotary Warblers of Beidler Forest will complete their migrations and return in the spring to provide additional data for Project PROTHO.

Images by Jeff Mollenhauer

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