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To predict the distributions of breeding birds in the state of Georgia, USA, we built hierarchical models consisting of 4 levels of nested mapping units of decreasing area: 90,000 ha, 3,600 ha, 144 ha, and 5.76 ha. We used the Partners in Flight database of point counts to generate presence and absence data at locations across the state of Georgia for 9 avian species: Acadian flycatcher (Empidonax virescens), brown-headed nuthatch (Sitta pusilla), Carolina wren (Thryothorus ludovicianus), indigo bunting (Passerina cyanea), northern cardinal (Cardinalis cardinalis), prairie warbler (Dendroica discolor), yellow-billed cuckoo (Coccyzus americanus), white-eyed vireo (Vireo griseus), and wood thrush (Hylocichla mustelina). At each location, we estimated hierarchical-level-specific habitat measurements using the Georgia GAP Analysis18 class land cover and other Geographic Information System sources. We created candidate, species-specific occupancy models based on previously reported relationships, and fit these using Markov chain Monte Carlo procedures implemented in OpenBugs. We then created a confidence model set for each species based on Akaike's Information Criterion. We found hierarchical habitat relationships for all species. Three-fold cross-validation estimates of model accuracy indicated an average overall correct classification rate of 60.5%. Comparisons with existing Georgia GAP Analysis models indicated that our models were more accurate overall. Our results provide guidance to wildlife scientists and managers seeking predict avian occurrence as a function of local and landscape-level habitat attributes. [ABSTRACT FROM AUTHOR]

Perfluoroalkyl acids (PFAAs) are widespread contaminants emanating from, among other sources, the production/degradation of fluorinated chemicals used in surface repellant applications, such as carpet manufacturing. The goal of the present study was to assess the concentrations of PFAAs, including perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUA), and perfluorooctane sulfonamide (PFOSA), in surface waters both near a wastewater land application system (LAS) in Dalton (GA, USA), home to North America's largest carpet manufacturing site, and distant to this location (Altamaha River, GA, USA) to understand the fate of PFAAs in freshwater. Levels of PFAAs were high in the Conasauga River (GA, USA) downstream of the LAS (PFOA, 253-1,150 ng/L; PFOS, 192-318 ng/L; PFNA, 202-369 ng/L; PFDA, 30.1-113 ng/L; PFUA, 58.0-99.2 ng/L; PFOSA, 162-283 ng/L) and in streams and ponds in Dalton (PFOA, 49.9-299 ng/L; PFOS, 15.8-120 ng/L), and were among the highest measured at a nonspill or direct-lease location. Perfluoroalkyl acids in the Altamaha River were much lower (PFOA, 3.0-3.1 ng/L; PFOS, 2.6-2.7 ng/L), but were a source of PFAAs to Georgia's estuaries. A preliminary hazard assessment indicated that concentrations of PFOS at two sites in the Conasauga River exceeded the threshold effect predicted for birds consuming aquatic organisms that are exposed continuously to the PFOS levels at these sites. Assuming that toxicity for all PFAAs quantified is equal to that of PFOS, the sum total PFAAs at two sites within the Conasauga River exceeded PFOS thresholds for aquatic and avian species, warranting additional research. [ABSTRACT FROM AUTHOR]