Project PROTHO Funded for Second Year!

In 2009, with help from TogetherGreen, Audubon South Carolina successfully initiated Project PROTHO, an innovative citizen-science project which is helping us learn more about the breeding biology of Prothonotary Warblers within old-growth forested wetlands at Francis Beidler Forest while educating visitors and students about their habitat requirements. Last year, we requested funds to build a foundation for Project PROTHO, this year we will restore 103 acres of Prothonotary Warbler breeding habitat within Four Holes Swamp. The innovative nest box design we are to use will be constructed from recycled materials. This year's summer campers created nearly one hundred nest boxes out of recycled ½ gallon milk/juice cartons.

Our target is the Prothonotary Warbler (Protonotaria citrea), a vibrant yellow, cavity-nesting bird that breeds in forested wetlands throughout the eastern United States. Point counts conducted in Beidler Forest during 2008 suggest that we may have as many as 2,000 pairs of Prothonotary Warblers breeding within the sanctuary. Due to its striking plumage and high nesting density along the boardwalk at Beidler Forest, the Prothonotary Warbler has become one of the bird species that most visitor’s associate with our sanctuary.

Prothonotary Warblers are neotropical migrants with wintering grounds from southern Mexico to northern South America. These birds are listed as yellow on the Audubon WatchList and as a high priority species on federal conservation plans for the southeastern United States. Breeding Bird Survey (BBS) data suggest that Prothonotary Warblers have declined in number by nearly 40% since 1966. Prothonotary Warbler population declines are likely a result of habitat loss and degradation. From 1960 to 1990 nearly 7.5 million acres of forested wetlands were lost in the United States, a decline of nearly 13% (Tulloch 1994). There are precious few forested wetlands left in the U.S. that support old-growth forest, the ideal nesting habitat of the Prothonotary Warbler because of its abundance of nesting cavities.

On their breeding grounds, the highest densities of Prothonotary Warblers are often found in mature forests, where there are abundant tree cavities. However, it is well-documented that Prothonotary Warblers will use nest boxes, particularly in areas that lack natural cavities.

Two hundred nest boxes will be placed on 69 acres of disturbed wetlands within the Francis Beidler Forest, while one hundred nest boxes will be placed on 34 acres of disturbed wetlands on private lands within the Four Holes Swamp watershed. While Beidler Forest contains 1,700 acres of old-growth, bald cypress-tupelo swamp, most of the remaining forest has been logged during the last 100 years. In these young forested wetlands, the natural nest cavities that Prothonotary Warblers require for nesting are less abundant than in the old-growth portions of the swamp. Studies have shown that installing nest boxes in these areas will increase nesting density and reproductive success.

Twenty five to fifty volunteers from the South Carolina Master Naturalist program will help us install the nest boxes at the five sites within the Four Holes Swamp watershed. A Project PROTHO intern will be hired to monitor the boxes throughout the nesting season. Upon conclusion of the 2010 breeding season, we will hold a meeting for private landowners in the Four Holes Swamp watershed to recruit additional landowners to participate in the nest box program and restore Prothonotary Warbler breeding habitat in 2011.

Images by Mark Musselman