Enhanced Habitat for Cerulean Warblers on the Chattahoochee National Forest

Nathan Klaus, Nongame-Endangered Wildlife Program
Jim Wentworth, Brasstown District Biologist, Chattahoochee National Forest

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The Cerulean Warbler (Dendroica cerulea) has been experiencing an average annual decline of 4.2% per year from 1966-2000 according to breeding bird survey data (Sauer et al. 2001).  This rate of decline was the greatest for any warbler species.    Several studies in the last decade have determined that the Cerulean Warbler is highly selective in its habitat requirements.  Specifically Cerulean Warblers as well as many other bird species favor mature, mesic hardwood sites with a diverse and well developed canopy structure including canopy gaps and associated midstory and understory vegetation.  Several mechanisms lead to a well developed canopy including natural mortality of old trees, storm damage, and uneven-aged timber harvest.  Because of historic land management most Georgia hardwood forests have unnaturally low levels of tree mortality and a poorly developed canopy.  

In 1999 the Georgia Dept. of Natural Resources and the USFS set about to improve this situation.  Thirty sites were identified based on forest type, elevation and other characteristics as being suitable habitat for Cerulean Warblers.  Pretreatment surveys were conducted to ensure that no birds were present in treatment areas, and in the winter of 2004-2005 a combination of shelterwood and group selection harvests were installed, 15 in Ivy Log near where Ceruleans were already present and 15 on Coopers Creek WMA where no Ceruleans were known. 

We are excited to report that spring of 2005 we had our first Ceruleans move in, just a few months after the loggers left.  One male was detected in a shelterwood during point counts and at least two other males singing in other treatment areas spotted by birders.   We are hopeful that point counts in the coming years will show further increases in Georgias small Cerulean Warbler population, maybe even the addition of another population on Coopers Creek!