Audubon Louisiana Avian Biologist Katie Percy displays a Prothonotary Warbler for Bluebonnet Swamp Nature Center volunteer John Hartgerink and visiitors, from left, Frances Pallotta, 7, Cagney Pallottta, 6, and Liam Dennon, 3. Percy is collecting data on the health of the Prothonotary Warbers and offered the visitors a close up view. Prothonotary Warblers have seen a 40% decline in population since the 1960’s. The Prothonotary Warbler research program monitors nesting sites for nesting success and breeding productivity. The program also deploys small 0.5-gram geolocators on a number of birds to track migration.